Is my pressure gauge broken? I recently got an xtech pressure gauge that reads up to 160psi. My bike is a road bike that uses presta valves on the inner tubes.

Here's the gauge (the one at the bottom):
http://www.moruyabicycles.com.au/contents/en-uk/d377.html

When I pop it on the valve the reading only seems to go up to about 40 psi. I feel if I inflate my tires much more they might explode (they are pretty much rock solid and I was expecting a reading of something more like 100) - they seem to have the same level of inflation as I bought them.

So my question is, is there a special way in which I should be hooking this up? At the moment I'm just unscrewing the metal release thing on the presta valve and pushing the gauge on firmly. The gauge holds its reading even after you remove it, and I've tried resetting it by pressing it's release valve button but that doesn't seem to make any difference.

I'm guesssing it's busted but maybe I'm doing something silly.

I suggest borrowing a pump with a pressure gauge and pumping up your tyres with that. Then try your gauge once you know the tyre pressure. Bike shops and a lot of cyclists have a floor pump because they work better than the little portable pumps than most cyclists carry. And those have a gauge on them that's usually fairly accurate.

You say the pressure release button on the gauge "doesn't seem to make any difference". What do you mean - does the gauge drop back to zero? If not it's definitely busted.


Can I use titanium axle bolts on a steel frame? I'm thinking of doing so for the non-corrosive properties of titanium. Weight isn't an issue.

The thing I'm not sure of is the hardness of the titanium vs steel.

Presumably you're talking about a Profile or one of the other BMX hubs with ti hop-up bolts available. Yes, there is no issue. Were a bolt loose and able to rub dynamically against the frame, they could in theory chew it up because they'll probably be way harder. But if you're riding around with loose axle bolts you'll have other much more imminent problems.


Plastic rims and brake pads I have a pair of 16" plastic wheels on a scooter-bike that is slowly being refurbished.  The brakes have been tweaked to remove slop, and I have fitted new cables and brake levers.

The brake blocks are a bit old and I can hear them sliding on the plastic rims, so replacement seems in order.

Question What brake pad types are most suitable for plastic rims?   Pads for CF are supposed to be "gentle" on the rim, which is not really needed here.

Note this is not carbon fibre, it really is plastic.

I've searched the site and we have no answers about plastic wheels at all.

I have tried fitting some single and dual pivot road bike calipers but they just don't have enough reach, so I'm stuck with these stamped metal ones for now.

Edit - more detail, and photos with some decent zoom.

Closer shot of the wheel in question  The back is identical, cos there is no cassette.

Closer photo of the wheel's brake track.   Seems to be curved with age and/or wear.

Here's what looks to be the underlying problem - the pads are old and hard and are also intended for alloy wheels.

Finally - some clarification on the "Adult" in Adult scooter.  I'm 185 cm tall (6 foot 3 inches) and I can ride this with both hands on the handlebars, while standing straight.   Its not a kid size.  Also, I'm 9x kilos and this carries my weight fine.  It goes off a normal kerb/curb okay, but not up one because of the small wheel size.

I'm not sure what the style is named, but I've referred to it as a Macklemore scooter, and my calls it a Scooterbike.

Update - have replaced the pads with new ones.  The caliper arms were quite bent too, forcing uneven wear in the original pads.  Once brakes have bedded in, will compare braking.  If no better, will source some replacement 16" rims, probably two front wheels from kid's bikes will do

Kool Stop Composite Continental pads are designed for use with composite wheels. They are available in different colors to match the wheel. Many BMX riders complain of streaking on the brake surface. I would carefully clean any residue off the braking surface. Failure to do so will likely result in uneven braking. If these pads are unavailable check for BMX "mag" wheel pads or pads for composite wheels.


Andel crankset, BB axle length and chainline I was planning to buy an Andel Standard Track crankset. It uses 110mm axle bottom bracket, but the stock bracket on my bike is 103mm. Will this mess up my chainline?

It will be 3.5 mm off, and that is quite bad. Square taper bottom brackets aren't that expensive or difficult to replace, just get a correct one.


Cause of severe brake judder? I've got a 2018 Canyon Exceed (XC mountain bike) that has recently developed alarming judder in the front brake (SRAM Level T), to the point that it makes the forks "twang" backwards and forwards, depending on speed and braking effort. The headset adjustment is fine, it's just that the forks are lightweight XC model (SID) and therefore a little flexy and they really don't like the brake pulsing.

Holding a constant, light pressure on the brake lever while rotating the wheel by hand reveals that the brake grabs as each of the rotor arms pass through the calliper. Inspecting the rotor shows that the pad coverage extends a surprisingly long way down the arm:

Same thing but different lighting:

I was surprised by the inconsistency of the pad surface too, which seems to correspond to which bits of pad the long cooling slots pass over:

The bikes got a little over 700km on it, most of them quite dry. The last 50 were wetter. The rotors are the originals, but are well away from their wear limit (1.55mm) and don't vary in thickness (1.87mm all the way around). I did wonder whether the calliper spacer was on the wrong way around, leading to the pads being closer to the wheel centre than they should be, but according to the direction arrow, it's correct (from factory).

I can't explain why this has suddenly become a problem. My trail bike has similar brakes (Level TL), also still on the original rotors, has lead a much harder life (3x the mileage, more severe terrain), pad also extends down the rotor arm, but it has never shown this problem. The same light-pressure, turn the wheel by hand test shows no hint of grabbing.

Is the solution just a new set of pads? Bedded in differently? How can I avoid this problem returning?

Severe juddering causing movement in the fork when braking is unlikely to be because of the pads or rotors. I would recommend checking the tightness of your headset immediately. Even if the bolt doesn't seem loose while you're adjusting it, tighten it up a bit anyway, then take it for a ride to see if it solves your issue.


Rear wheel odd shape (goes up and down) fixit or buy new? I have what I think is Specialized  Hardrock mountain bike.

Recently, when riding on a flat surface the back wheel has a noticeable up-and-down movement with each spin. It is like ridding a horse in the merry-go-round.

When inspecting the wheel spin, I don't see a side movement and can't visibly see the up/down movement, but I can easily feel it to the point that I do not want to ride the bike.

What are the options and costs? Consider I am not a fix-it-yourself bike person.

Your description sounds like the wheel is out of true, out of round, or some of the spokes are so loose that they're flexing as the wheel rotates. However, for it to be as severe as you describe I would expect it to be visible on spinning the wheel and watching it, even to a novice mechanic.

Whatever the case, you should take your bike to a qualified mechanic. The problem may be fixable, possibly as simple as tightening and loosening the appropriate spokes. This is a relatively difficult job for a novice mechanic though. It is also perfectly possible that you need a new wheel. An experienced mechanic would have to visibly inspect the wheel to be sure.

If it's a simple fix, it could be as low as $15 US. If you need a new wheel, I would expect it to be around $75-125 for a bike that age depending on what quality you would like to get.

I would also recommend checking with a couple mechanics. Some are quick to sell new parts when an older part is serviceable.


Does a torque anchor prevent an IGH (Rohloff Speedhub 14) from being pulled forwards and crooked whilst riding? Assume a bicycle with horizontal fork ends (like the rear facing horizontal fork ends on a Surly Troll), with an IGH (Rohloff Speedhub 14) and no chain tensioner.

On a steep uphill in the easiest gear, the rear wheel might be pulled forwards and crooked.

Does a torque anchor prevent this? Or is a torque anchor used to solve a different problem? (I'm refering to this answer (https://bicycles.stackexchange.com/a/56660/31142) to my question about Surly + Rohloff which mentions a torque anchor.)

No. The torque anchor is on the non drive side and only serves to counteract rotation of the inner part of the hub. Use Tugnuts or equivalent if you think the wheel might be misaligned due to pedaling force.


What is considered a small hand for shimano? The new shimano r7000 offers two options r7025 and r7000 in the brake levers, the first one is for small hands.

What is considered small hands?

You'd probably have to try it and see which is most ergonomic for you; even if you have large hands, the small hands lever may feel better. Older levers came with a rubber piece to stick in the brifter to adjust for smaller hands, but this has limited differences versus a different lever.

Most females would fit into the small hands group. Younger males up to some age might as well. Adult males of average or larger size would likely not.


Carrera Crossfire 2 Hybrid Bike to a road bike I have a Carrera Crossfire 2 Hybrid Bike. I would like to convert this to a full road bike. Is it possible?, if so what changes will I need to make.

it is possible, but in most cases does not worth it.

Components cost more if sold separately, so usually you end up spending a same amount of money or even more than buying a new bike.

if any seller does discounts on bike - consider you have all the components discounted

planning and implementing conversion is not easy and time consuming


What is the difference between disk brake rotors? Differences in rotors include size, thickness, pattern cut out of the metal and attachment to the hub. What other differences are their and why? Reason I ask is I recently built up a budget mountain bike and most parts I bought or borrowed from other bikes. One part I borrowed is the discs from another very cheap mountain bike I had (an Apollo) - they seem thicker and heavier than the discs on a Kona Hoss that I have. The brakes on my bike build aren't working brilliantly. Braking is ok but there isn't much modulation. They aren't expensive brakes but they were bought new - Shimano alivio and I'm wondering if the type of discs do play a part?

This question has another answer here

There's also the rotor design.   There should be holes such that the whole brake pad presses over a void, and several times in the rotation.  Some really poor rotors don't have holes arranged right, so one circle of rotor is plain metal the whole way.  This doesn't clean the pad and contributes to bad braking.

Thickness is partially to cope with heat.  More mass takes longer to heat to extreme levels.  Less mass is lighter for riding.  Also thicker rotors will resist bending more-so than thinner ones of any quality.

Rotor Size or Diameter is a design thing, not a quality thing.  You need the rotor to suit the location of your calipers, and they will depend on the fork mounts and the rating of the fork.  Same goes for the ISO 6 bolt holes or for the centerlock style - it is yet another competing standard with relatively minimal effective braking differences.


What are the most highly attended US & International charity bicycle rides? Yep, it's all right there in the title. Thx!

I am not sure how you would find the individual rides with the highest participation, but there are a few organizations that reach thousands of cyclists across the US by holding rides in several communities.

In the US you tend to rarely see huge rides because the logistics and regulation hoops in many areas is to great to overcome.  Many rides are capped at 2000 or 3000 riders.

The list below is based on my perception that they hold the larger rides in the most areas:

MS Bike Rides (National Multiple Sclerosis Society): Most are two day rides and many rides attract 3,000 riders or more.

LIVESTRONG (Cancer - Lance Armstrong Foundation): In addition to 3-4 of their own large rides, they have begun to sponsor other large ride like RAGBRAI.

Tour de Cure (American Diabetes Association) Their site reports that between the 80 or so rides they sponsor they get 40,000 participants.

There are a lot of others like Team in Training, American Lung Association Rides, etc, but those three have charity rides as one of the primary fundraising activities and are fairly well known throughout the US.


Where can I find vintage hardware to mount a Raleigh 3 bolt chainring? I need hardware (3 short bolts) for my Raleigh Super Course 10 speed made in Nottingham England in 1973.

The bolts hold the front large chainring to the smaller chainring that the pedals are mounted to.   Can these bolts be purchased?

Based on the "three bolts"  you have something similar to this image, which appears to use three simple bolts, although I can't find what the threading is.

  TL;DR, there's an updated answer below all this waffle.

Sheldon's relevant page is at https://www.sheldonbrown.com/raleigh26.html and specifically fingers the Nottingham factory for making up their own standards, and did this right through to the 1990s.

If you have access to one of the bolts, then its possible to identify it using some basic machining tools.

A Thread pitch gauge will tell you how many turns per inch (TPI) (aka the "pitch")
A micrometer or Vernier caliper will tell you the outer diameter.  It will probably be a straight thread - if the diameter changes along the length, then it could be a tapered thread
Eyeball the thread form - is it an even triangle (most likely) or something weird.

More info at https://www.classicfasteners.com.au/content/Identifying_threads.pdf and

A couple of useful thread identication charts are

http://almetal.nl/en/techinfo/gti/ticas.htm
https://www.portlandbolt.com/technical/thread-pitch-chart/
https://www.boltdepot.com/fastener-information/printable-tools/default.aspx

I'd just about guarantee its not a metric thread, but it could be Imperial,  UNF, UNEF, or something older and weirder like Whitworth.  Heck I even have some "BA2" bolts in my British Landrover from 1973, that standard dates from the days of steam boilers!

Still possible that Raleigh were completely alone and used their own standard bolts too - which may need to be made specially.  You could potentially retap the holes to a normal metric standard bolt too.

Finally if you don't have the bolt, all this is possible to measure using the threaded hole in the crank too.  Just a lot more fiddly.

If you do buy commercial bolts, try for stainless steel or high tensile (or both if you can) and use antisieze.  Try and avoid using the cheapest low-carbon chinese cheese bolts from the local discount store.

UPDATE

  I believe the 3 chainring bolts are 9/32" Outer Diameter and the thread is a 26 tpi whitworth thread.

From https://www.bikeforums.net/classic-vintage/703071-chainring-bolts-cottered-3-arm-crankset.html

There is also some discussion that a metric M7x1.0 thread will "fit"

The observant will object and point out that

Metric flanks have an angle of 60 degrees whereas Whitworth is 55 degrees,
Metric pitch of 1.0 translates to 25.4 tpi while Raleigh's propriety threading is 26 tpi
and 9/32"= 0.28125 " = 7.14375 mm which is pretty close to a 7mm bolt.

Add some thread locker to help stop it walking out, or you might have room for a jam-nut on the other side, maybe.


how much can i raise my stem? I've got one of these stems:

It's currently fully inserted into the bike, and it's too low for me.

Can I simply loosen it, raise it 5cm and tighten it again?

What's the minimum length that should be inserted? will there be markings like on the seatpost?

The stem is Aluminum. The frame is Steel.

With most older quill stems, there must be a minimum of one inch of the stem (above the binder wedge) inside the frame for safety.

Most stems have marks on them similar to seat posts, yes. The longer the quill, the more of the stem needs to be in the frame. I suggest 25% of the length as a minimum.

The scratch marks on the stem in the photo you linked show about where that one should be inserted as a minimum.

Yes, you can loosen the bolt and slide the stem farther up, to raise it, with this style stem. How much you can raise it varies by model and your frame.


Tube constantly getting punctured near the valve I have been using my bike for a few years now, and for the last month i am constantly getting this problem. After riding a day or two, it looks like my tube gets rotated a little inside the tire, and the valve becomes bent. If i continue riding, the tube gets torn. So i have to remove the tire, wiggle the tube a bit, and it's back to normal for a few days.

The tube seems to fit very well, and i don't notice any inconvenience when inserting it, so maybe my problem is not caused by bad tubes (or maybe it is? how can i make sure?)

Another thing that might be relevant: i started riding moderately technical terrain in the last year (going down rocky roads, riding downstairs in the city). The problems started just a month ago; maybe the additional stress, combined with the warm weather (25-30°C now), is the cause?

I also use anti-puncture tape.

So, what causes my problem? How can i fix it?

New tube:

After some riding:

After a puncture:

I would bet this is caused by a tire with rubber that got "old". This tends to happen to MTB tires that are repeatedly ridden on mud, and I had some tires with this behaviour before.

The problem seems to be insuficcient friction between the rubber and the rim around the bead, specially on those tires with a material resembling fabric on that region (like it seems to be your case, judging by the first photo), and are worse on the front tire since it applies traction only while braking - the rotational force is always applied in the same direction.

One measure to take, as already mentioned, is to put a higher pressure on the tire. It might allow you to get home without damaging a spare tube, but it's not the ideal solution since the slipping tendency is still there anyway, and sooner or later the tire ends up slipping, most probably when you don't expect.

One other measure, that actually works very fine, is to "reactivate" the rubber on the groove where the rim and the tire "seat" against each other, considering that:

In tires with old rubber, many times the said surface is "shiny", or "glassy", or "vitrified", or "mirror-like";
In tires with fabric in the bead, the rubber "disappears" with use, and the slippy underlying fabric is left to make contact with the rim.

Both conditions contribute for the slipping due to reduced friction coefficient. So, to REACTIVATE the grippiness of the material, you should:

Take the tire from the bike and wash it with plenty of water until it is completely wet. Since the tire is off, you can wash the rim either;
Brush the bead groove vigorously with a properly-sized brush, applying some abrasive soap mixed with water. Mechanics soap could be great but maybe too violent. I had excelent results with toothpaste (seriously!), and even with glycerin soap without abrasives. In any case, adding water enough to get a good foam is much better than just rubbing the dry product on the rubber. Rinse repeatedly after this with pure water, aiding with the brush;
Optionally, at last you can apply those products to make car tires "shiny". These tend to somehow protect the rubber from getting dry and glassy again.
Important: assemble and inflate the tire while it is still wet.

I had tires almost unusable because of this slipping problem, and the problem disappeared like magic after performing these steps.

As an additional fact, any modifications I tried to make in the rim (cleaning, sanding, filing, grooving) had no effect.

Hope this helps!


Best chain lubricant for commuter/utility bikes? What's the best chain lubricant for a bike used for riding in normal(ish) clothes, year-round?

I've been using Tri-Flow, but that tends to leave black greasy/dirty stains on pants, shoes, etc. I've heard of melting solid parafin, but that seems too labor-intensive.

Most important: not picking up dirt; not staining anything that touches the chain.  (yes, I know of various ways to keep clothes away from the chain, but none are perfect)

Must also work in a wide temp range and wet conditions. For my area, I'll ride in temps from 30F (-1C) to 106F (41C). With heavy rains in winter. Just this last week I've ridden in drizzle, 55F (13C), and 107F (42C)…

Would be nice if it was long-lasting…

Tri-Flow works the best.  Any wax or lubricant that contains wax is only somewhat useful on a brand new chain, or a chain that has been thoroughly cleaned.  Wax lubricant does not work well when riding in wet conditions because a lot more road grime gets kicked up into the drive train and the wax tends to do the opposite of what is advertised.

You aren't going to find a chain that doesn't leave stains on your clothes.  Your best bet is to get a chain protector to keep your clothes and your chain separated.


Biking Target Speeds On a road bike what is a good target solo speed for someone who wants to be a better than average cyclist?
Like is there a certain speed where you know as a cyclist you are doing pretty good like 20 MPH+ for an extended period of time?
What is the speed and duration in time/distance one would need to be able to sustain in order to consider semi-pro racing (male rider)?

I agree with Criggie's answer, but there's another way to look at it. Speed is mostly a function of power output. And you can quantify a cyclist's fitness in terms of their power-to-weight ratio, that is, W/kg.
This article shows what cyclists of different levels can produce in terms of W/kg, how long they can maintain different levels of output, etc. There's a lot there.
You can take that information and plug it into this calculator to estimate speed based on power and other conditions. You'll note that it takes a lot of additional power to go just a little faster.


Can I trust a carbon-fiber repair? https://www.kijiji.ca/v-road-bike/city-of-toronto/felt-z4-carbon-road-bike/1497484952

That's the bike, I'm just concerned about the carbon frame repair.

Seller said he did it himself and has done many frames before, and can guarantee its lifetime in writing.

Are there any specifics I should look for when I examine the bike ?

How do I know it is safe to ride ?

It might be hard to tell by closely inspecting the repair how well the work was done, or for that matter how badly the frame was damaged. I would ask to see pics of how the damage looked prior to repair. I would inquire about his experience repairing carbon frames, see if he has any testimonies from other customers. I assume he buys cracked frames and repairs them to resell as a business or side job? It might be great work, but a testimony would help me decide. I would also dig around a little to figure what the value of that build would be if the frame had not been damaged.Maybe you can find a similar build priced well that hasn't been damaged?
Take it for a good test ride. See if he can offer a return if anything goes wrong at the damaged stay within a set time frame. Try to talk him down? These are all things I would try. It really just depends on how much you want the bike and how much you trust the guy you are doing business with.


Front tire & downtube clearance - extremely dangerous? I recently moved cities and met someone to buy a used "vintage" bike from them. While test riding at a slow speed I gradually applied the brakes. The front brake seemed to jump from light pressure to completely locking the front wheel at once and threw me over the top promptly!
My first thought was that the front wheel was out of true - causing the brake to apply harder as the other side of the wheel came around. However, the wheel was mostly straight.
Eventually I discovered that when braking, the frame and fork were flexing enough to cause the downtube to contact the front wheel. This contact caused the downtube to completely seize the front wheel instantly.
Has anyone else encountered this before? What fix would you even go about to stop the downtube from striking the front tire? I searched online and didn't find similar stories - so perhaps this super dangerous maintenance issues is rather uncommon?

Shogun Selectra - old frame, probably from the 90's
62cm frame
700c wheels
Rubino 28mm tires (seller said previous owner had 32mm tires) I didn't get the exact rim measurements. Tires seamed an average height for modern road tires
wheels mostly true
plenty of clearance for the tires in the fork (next time I'll have to check the downtube too)

edit - photos from comment

The frame paint was indeed worn away at the contact point between the front tyre and downtube - though looked like erosion over a long period of rubbing.

Yes, extremely dangerous, as evidenced by your falling over the handlebars
It's evident from the photograph you linked, that the fork is pushed backwards, bringing the wheel much too close to the frame. The most likely reason for this would be crash damage, given that the fork is facing the right way.
There are two hazards then, one is locking the front wheel instantly under braking, while the other is hidden (or even visible) damage to the fork, risking structural failure. This is likely repairable with a new fork and inspection of the frame, but happily you've passed on purchasing this time. Caveat emptor I suppose


Is there any significant gain of the bell super 3r mips over the 2r mips? I am looking into buying a full face helmet with a removable chin bar, both the bell super 2r mips and bell super 3r mips seem to a good choice. The super 2r is about 90 pounds cheaper than the 3r and i would like to know if there is any big reason to get the 3r over the 2r.

Thanks.

I would imagine the 3R is just more refined. We don't do product recommendations so to speak but comparing the two on the Bell website should suffice in helping you determine if it is worth the extra money for what you will be using it for.

The website lists the major difference as:

  For the new Super 3R, we’ve added the new Float Fit system and dramatically improved the fit and comfort by revising the shape both inside and out

In addition i would compare the product specs and see which is better for you, your wallet and your intended application.

2R -

Breakaway Screws
Fusion In-Mold Polycarbonate Shell
Goggleguide™ Adjustable Visor System
Integrated Breakaway Camera Mount
MIPS-Equipped
Overbrow Ventilation™
TAG™ Fit System
Wraparound Protection™
X-Static® Padding

WEIGHT: 694 Grams
VENTS: 23 helmet, 4 brow ports, 6 chin-bar

3R -

Breakaway Screws
Float Fit™
Fusion In-Mold Polycarbonate Shell
Goggleguide™ Adjustable Visor System
Integrated Breakaway Camera Mount
MIPS-Equipped
Overbrow Ventilation™
Wraparound Protection™
X-Static® Padding

WEIGHT: 784.1 Grams
VENTS: 23 helmet, 4 brow ports, 6 chin-bar vents

Seems to me the major difference is the 3R uses an improved fit system while also weighing nearly 100 grams more. Other than this my guess is the price difference is simply because the 3R is the newer aka latest and greatest.

Also i would recommend trying them both on if at all possible, when it comes to full face helmets a large of one brand is totally different then the large of another and the fit and comfort can very greatly.

My personal opinion would be to go with one with permanently attached chin bar, but that's just me. If i'm depending on something to guard my mouth, i would rather it not easily detach and reattach. I ride the tamer trails around me with it as well now that i am used to it, it really doesn't bother me. I do get some odd looks every now and then though.

Hope this helps


Climbing techique with panniers and cleats In the last year I started using cleats (2 bolts SPD) on my touring bike, which I often use with rear panniers on biking holiday (travelled about 2000 km with this set up).

The struggle I have is when cycling on a steep climb: in certain cases, when I am already using the shortest gears, I have to trade off between two opposite necessities:

if I push harder without standing on the pedals I end up lifting my front wheel
if I don't push harder I go too slow to keep a decent equilibrium

Until I used clip less pedals I could easily put my foot on the ground in case of necessity, but now the concern of having locked feet adds another source of uncertainty.

I have tried releasing one foot during the climb, but it goes without saying that pedaling gets way more clumsy.

What is a good technique to climb steep road with cleats and back panniers?

One thing that may help a lot is shifting some load weight forwards.  In other situations I've found that a surprisingly small amount of weight shifted from behind the back axle to the front forks improves handling a lot.  For example rather than mounting a D lock behind a child seat, I put it on the front forks. That's something like 1% of the total weight, or 4% of the non-rider weight.

This may lead to a bar bag, bar/fork-mounted bottle holders, or front panniers, though I'm trying to avoid the latter (as it seems are you).

Even loading differently within the panniers might make a difference.


Is it worth rebuilding a wheel myself to save money? The bearings and hubs on my bike have worn out and need replacing. The local bike shop charges $120 to have the wheel rebuilt with a new hub not including the part cost. I am considering doing this myself to save the money. I have never rebuilt a wheel before but I have done other maintenance on my bike and watched some videos on wheel rebuilding.

After considering buying the tools needed and the risk of breaking any parts, is it worth building a wheel for the first time just to save money?

I have done other repairs like chain replacements and brake pad replacements. I don't mind spending a weekend messing with it and I have other bikes I can use in the meantime.

For most applications, most of the time, in the global north, if you're trying to save money then just buying a new wheel is the most economical. The main exception  that comes up is if you have a premium quality hub that's built to go indefinitely and is worth re-rimming.

But, good handbuilt wheels offer the highest level of reliability and longevity, and that can have its own economy depending on your situation. In practice a major example of this is that they don't break spokes from fatigue over the course of the service life of the wheel (and really ever with properly stress relieved spokes, but that's a bigger topic) whereas the cheaper end of machine built wheels often will, pushing back against the cost savings of buying one for a bike that gets ridden. And there are also times and places where a rim with life left isn't something you'd throw away. So there is no one answer here. A person who really needs their bike to work as best as possible and also needs to spend the minimum amount of money possible might be perfectly well advised to rebuild the rim.

Another factor is that the world has an overabundance of functional cheap or free used hubs with life left from wheels where the rim died. If you can get a suitable one of those and if minimizing cost is literally the only goal and if you've definitely got a rim with life left, then you're only out the cost of spokes and rebuilding it might make all kinds of sense.

Most rim brake rims are going to be pretty haggard by the time a hub has actually worn out. (Note that 'worn out' implies a different situation than a hub that had issues or failed.) There are exceptions here too; I've rebuilt one or two Dura Ace C50 tubular rims whose hubs died by pressure washer. That's obviously kind of an extreme example, but it happened.

Disc rims that aren't being mountain biked on can have pretty easy lives, especially when paired with a fat tire that's minimizing the severity of the fatigue cycles it experiences.

When rebuilding a used rim or contemplating it, it's a good idea to check for any out of round or out of true spots that are intrinsic to the rim itself, i.e. acquired via damage. A very good way to do this is take the bare rim and lay it on top of a new, high-quality, preferably machined sidewall rim of the same size. Any radial or lateral deformation should be apparent. To be able to get a true wheel with even spoke tension, you want the bare rim to have zero perceptible radial deformation, either flat spots or ovalisation, and 1-2 mm of lateral imperfection at most. (There are methods and tools for getting rims with any of these issues back into shape or at least making them better, but that's another topic.)

When unlacing a rim you intend to rebuild, be gradual so you avoid bending the material around too much. I do half turn loosening passes until the spokes are slack, then I do the rest all at once or cut if they're not being re-used (which they usually shouldn't be).


What makes a bike stay upright when moving? What makes a bike stay upright when it is in motion?  What is the relationship between speed and stability?  Is it a linear relationship?

I could ask this on the physics site however I am hoping for a relatively simple answer.  I took an introductory class in physics in University so basic physics is appreciated but nothing too gnarly.

I think that it is not the spinning mass of the wheel that is keeping the bike upright.  I read a study recently stating that if you have a wheel with identical mass spinning backwards beside the bike the bike will not lose stability.  (I am not sure where I read the study).

Why do bikes stay upright when on a roller?

This question was recently the subject of a lengthy article in New Scientist magazine. To summarize:

  "Why does this bicycle steer the proper amounts at the proper times to assure self-stability?" the paper asks. "We have found no simple physical explanation."

http://www.newscientist.com/article/mg21028141.700-bike-to-the-drawing-board.html

This article also cites the study that you could not quite place - gyroscopic forces, for so long thought to be the be all and end all of bicycle stability - have been scientifically proven to not be of the consequence popularly imagined.

As for staying upright on a roller, that is not covered by the article, however, it does discuss what happens when you send a bike off down the street with nobody on it - seemingly the weight and steering adjustments made by the rider have nothing to do with it.

I don't think that the New Scientist article is the last word on the subject. However it is recent (a few weeks old) and is a good introduction to the mystery. Enjoy!


Least worn tyre: front or back? Where should I put the least worn tyre? on the front or the back? This is for XC MTB.

The Good or less worn tire should go on the front wheel as indicated in this Sheldon Brown Article on Tire Rotation
Although the article does hint to the fact that you should not be really rotating tires to the front wheel that may have been used on the rear wheel.

The only time tire rotation is appropriate on a bicycle is when you are replacing the rear tire. If you feel like taking the trouble, and use the same type of tire front and rear, you should move the front tire to the rear wheel, and install the new tire in front.
The reason for this is that the front tire is much more critical for safety than the rear, so you should have the more reliable tire on the front.
If you have a blowout, if it is on the rear tire, you have a very good chance of bringing the bike to a controlled stop. If your front tire blows, you can lose steering control, and a crash is a real possibility.


Commuting 36 kms, 5 days a week My workplace is 18 kms ( 11 miles ) away from home. I am planning to commute to and from every workday, 5 days a week.

My stats -

6'1" (185 cms )
82 kgs (180 lb )

I generally average around 22 km/h while going and coming (13 mi/hr). The commute takes about 50 mins, I am in the  zone for 30-35 mins.

I am able to follow this routine, but worry that I am overdoing it. I feel that I am loosing muscle mass.

So far, I do no weight / strength training. Eat a normal and healthy 3 course.

Can anyone please give me idea about -

Diet regiment. ( I really hope suppliments can be avoided.)
Body weight exercises if any is required. I hope I can avoid the gym.

The aim that I am able to achieve is to keep continue cycling with this routine hopefully generally around 15mph ( 25 kmph )

If you are feeling physically worn out by the commute and you are not used to, well, you are just tiring yourself out and not allowing you muscles to recover between rides.

Keep riding and your body will eventually adapt. Maybe you want to do this commute every other day for a while, or at a slower pace to help you your body strengthen itself.

Simply riding will build strength and endurance. Doing some body weight core exercises will probably help stabilize you torso and let your legs work efficiently.


Can I replace a 135mm/5mm QR hub with a 10mm-diameter IGH? I have a bike whose rear wheel has "quick-release 5 x 135mm". Will I be able to replace this rear hub with an in-gear hub that has "Length 135 mm, Axis diameter 10 mm" (this is the N380 hub)?

With a quick release system there are two potential width measurements: the inner width of the axel (which a skewer fits into) and the outer width of the hollow axle.  The "quick-release 5 x 135mm" likely refers to the width of the quick release skewer diameter/width and the "Length 135 mm, Axis diameter 10 mm" is referring to outer diameter of the axel which fits into the frame.

For your hub swap, the outer diameter of the axel is matters as this is what fits into your frame.  As rear quick release systems used a 10 mm rear axel, the hub should fit.

Finally, if your frame is a quick release frame, you likely have vertical dropouts.  These are not always compatible with internally geared hubs.  You should ensure your frame is compatible with your internally geared hub.


How to extend a chain for a cargo bike? I have a KMC x10e chain which is 162 links long on my Xtracycle electric cargo bike.  The chain is worn and I am trying to replace it.  From what I can tell it is available only in 136 links. Is the way to get to 162 to buy two and combine them?  Or is it possible to buy a custom chain at exactly the length needed or buy a long one and reduce it to 162?

Your local bike shop might (see comments on the might) buy chain in bulk and can cut it off at precisely the length you need. Get a quick link at the same time so you can easily put the chain on or remove it.

They may have limited selection, though, especially as you’re looking at a speciality chain- a 10 speed chain designed for ebike torques. So they may not have this as a bulk item. Bike shops that specialize in cargo bikes and recumbents are your best bet.

Otherwise, you’ll have to break and conjoin two shorter chains. Be sure to get the same brand and model chain as slight differences in chain width or profile can cause shifting issues. You’ll need a 10-speed compatible chain tool to break one of the chains to length. There’s generally no problem using the quick links to put the chains back together again as long as they’re the links provided in the box.

But back to the speciality chain issue. Many of us think there’s a great deal of “marketing” and much less “engineering” around ebike parts. Given that a top sprinter can easily put out 1500 watts, a high quality 10-speed chain should be able to handle many mid-drive motors which are 750-1000 Watts. My main caution would be to make sure your motor controller has a shift sensor so it de-torques during derailleur shifts as shifting under max epower can snap even the strongest chain.


How to prevent hood covers from slipping up? I noticed my hood covers (the rubber one) are slipping up -- I pull them down, align with hoods, some time later again (when riding of course) -- they are up. It is really annoying. Granted I put my hands on them, and with the force it is expected in sense of the physics, but I would like them to stay put as they did last year.
Is it a matter of time, I use those hoods and covers the 3rd year, or there is a way/trick to make them sit put and don't move? Hardcore gluing hoods and covers together is not a best option since this in turn blocks access to hood screws and makes replacing bar tape harder.
My brifters are Shimano Sora STI.

I've also got Sora brifters, and the hoods do eventually wear out. I replaced the rubber parts after about 2 years, maybe 20 000km, and several gear cables. They're readily available as spares, but be sure to get the exact model


Is it ok to hang the bike by the frame, if the bowden is on the bottom? Related: there are plenty of Q&A's (both here and on other sides), according to which, apparently, it is ok to hang a bike by its wheel.
What I didn't find though is, if it is ok to hang the bike by the frame, if the bowden goes below the frame, thus the bowden cable and the frame would be pushed together. Could it e.g. cause the bowden to wear quicker? Or slightly misadjust the rear brake?
Especially if the bike hangs for longer periods, say up to six months.

Not going to do anything, unless the bike weighs 300 lbs or something.
Worst case if you're hanging and removing repeatedly you could scuff the paint, from the housing rubbing against the frame. But of course, your mounts pose the same risks.


When do my brake pads need replacement? I have a bike that is almost two years old. It still has the original brakes (side pull caliper brakes), which seem to still be functional. However, they are worn and I am going to be doing a lot of biking out of town during the next two weeks.

I think I know how to replace my brake pads, but I don't know if they still have plenty of life left or are about to go. What should I look for? How can I tell when they need to be replaced?

There must be some wear indicating lines on your brake pads. If you don't see them - it's time to replace the pads.

Here is an example of wear indicator lines:


What can I expect within a year? I've just started road cycling 1.5 months ago, I'm a 15 year old guy with no serious experience, my avg speed on a road bike is 16,8mph is that a good speed?, what can i expect in one year in terms of my speed?

You're still young - at 15 you are still growing, so work on endurance and technique, and not too much on raw power.
And remember its not about ultimate top speed, there's got to be an element of enjoyment too.  So work on enjoying your time on the bike, but also have a life off the bike.


Parking rear-wheel first: which sprocket to put rear derailleur in? So, I want to keep this from happening:

To that end, I like to park my bicycle rear-wheel first, which was discussed in answers to this question, where I'm taking the images from. Since almost everywhere I need to leave my bike the stands tend to be of the variety you stick your front wheel into (image below), I like to park my bike rear-wheel first and lock the frame to the rack. Most of the time, the rack has space for the rear derailleur either inside or outside the rack.

This brings me to my question: Should the rear derailleur be between the tines of the rack, or should it be outside the structure? In other words, which sprocket should I have the chain on when it goes to the rack? For purposes of this question, please assume I don't have a kickstand.

You're unlikely to get the derailleur outside the rack with much clearance, so the chances of knocking it getting the bike out again are quite high. It may even be possible for someone to bump the back wheel and bend your derailleur.

Selecting a bigger sprocket also puts the derailleur further forward. This is likely to improve the clearance around it but of course that depends how your bike sits in the rack.

Cross-chaining into a big ring and a big sprocket brings the derailleur even further forwards, but change out of this when you get going.

You may also want to invest in security skewers and/or an extra lock for your front wheel. Your local bike thieves sound like they have a surplus of bikes without front wheels.


Can I put a 8 speed bike on a Elite Suito 11 speed direct drive turbo trainer I have recently ordered an Elite Suito Direct Drive FE-C turbo trainer. The main use is for indoor, winter cross-training for my young son who's a keen athlete (we don't want to send him out in the dark on his own and I can't keep up with him any more) but I and my wife would like to use it too and we'd all like to use the same bike on the trainer. The tentative plan is to put my wife's step-through Dawes Discovery 301 hybrid bike on the trainer, as the frame is small enough for my son to manage and just about big enough for me (I might need to put a longer seat post in), so no frame swapping would be required.
The Dawes 301 has 8 cogs/sprockets at the back and 3 at the front, i.e. 24 speed. From a bit of googling, the rear cog (cassette?) on the bike may be a Shimano CS-HG30 11-30T, the rear wheel hub a Shimano FH-RM60 36H QR and the front cog (crankset?) a Shimano FC-M191 48/38/28T.
The specs for Elite Suito trainer include the following info:

"Compatible with 9, 10 and 11-speed Shimano and SRAM cassettes (not included), can be adapted for Campagnolo using adaptor TT14233 or SRAM XDR using adaptor TT14279"
"Compatible with 130 and 135 mm quick-release frames as well as 142 x 12 mm thru-axles, adaptors for BOOST 148 x 12 frames are available separately"

My question is, can I use this Dawes bike frame with the Elite Suito trainer and if so, what is the best way of doing this? For example:

can I take the 8 speed cog off the back wheel of the bike and use it to replace the 11 speed one that is supplied with the trainer; I'm guessing not because the trainer specs say it's only compatible with 9,10, or 11 speed cassettes but is there a workaround?
if not, what is likely to be the cheapest solution to get a basic, mid-size frame up and running with the trainer, e.g. would I need to swap out all of the drivetrain on the Dawes bike (front and rear cogs, front and rear derailleurs, shifters, chain) and if so, would it be cheaper to buy a compatible 2nd hand bike instead (if yes, what specs am I looking for)?

Apologies if my terminology is incorrect but I know virtually nothing about the technicalities of bike design and maintenance, as you can probably tell. Thanks in advance.

Yes, you can also use your 8-speed cassette on 9/10 or 11 speed hubs. They just ignore it as 8-speed is something too cheap and people using such a trainer would probably have something "better".
You need to use the same 1.85 mm spacer you would use for 9 and 10 speed cassettes on the 11-speed hub. If the spacer did not come with the trainer, you have to buy it.
The frame should also be perfectly compatible.


Absoluteblack oval chainring doesn't completely fit GRX crankset I'm trying to install an absoluteblack oval chainring on a GRX FC-RX810-1  crankset.
After assembling and tightening the bolts I noticed there's a gap between the chainring and the crankarm.
Basically, only 1 out of 4 bolts puts the chainring totally flush, the other 3 have about 1mm gap (see the photos below).
I'm wondering is this acceptable or should be considered a defect?
Thank you.

For future reference, these particular chainrings will fit just about any Shimano 4 bolt EXCEPT the GRX. They mount a bit strange compared to many chainrings as you can see in this image, the bolt comes through the crankset from behind and screws into the chainring.

Compatibility
Shimano Dura-Ace 9100, R9120, R9150 & R9170 Di2, Ultegra 8000, R8020, R8050 & 8070 Di2., >105 R7000, R7020, R7070, Dura-Ace 9000, Ultegra 6800, Shimano 105 5800, Tiagra 4700 ; 10 >/ 11 / 12spd compatible. In short ALL Shimano 4 bolt cranks except GRX.
Chainring has 1.5mm offset towards frame for perfect chainline.

Source: Absolute Black


Is this new wheel out of true? I just got a new road bike. Is this front wheel out of true? Or is it an acceptable amount of movement? I'm only using it to commute 10 miles a couple times a week.

Thanks.

https://streamable.com/m30il

The pads are positioned reasonably close to the rim so the brakes are probably be adjusted correctly. The does not appear to be rubbing on the pads. It will most likely not be a problem.

Whether this is acceptable on a new bike depends on the quality and cost of the bike. Most bicycle purchases come with a free tune-up after a short period of time, and a good bike store should deal with minor issues for no cost. Have the store take a look at it.


How can I fit 6 bikes on a hitch rack? How can I fit 6 bikes on a hitch rack for my Toyota Sienna van?  Thank you!

Here's a rack that will do six. I have no personal experience with this one and the fact that neither of the top two rack companies (Thule and Yakima) do a six bike rack makes me think you should approach with caution.

[Link removed due to the old link being expired/stale. The link was to a "Northshore 6 Bike Rack"]

I have seen, with mixed success, 4-bike bike racks where folks have strapped an additional bike into the mix. Again, proceed with caution.


New wheels for Trek 7.3 I broke a spoke on my rear wheel the other day.  When I took it to my LBS they recommended replacing the wheel all together; stating that it could no longer be trued effectively because the spokes were "frozen" (basically they were difficult unscrew the spoke & nipple).  My wheels are original, as are the spokes and hub (except for the one replaced spoke).  They also mentioned that my rear cassette and chain was about to wear out and brakes needed to be removed and cleaned because they are sticking.

The stock rims are bontrager nebula 6000 series (622x15).

In the land of replacement wheels what would be and equivalent wheel?  Should I consider getting a new hub as well?

Is it worth (I know subjective) having all this work done simultaneously?

Some of the answer depends on what kind of riding and how much riding you do and how much money you want to spend.  As a previous responder indicated some of the stock factory wheelsets are fairly inexpensive.  Check Nashbar and elsewhere on the Web.  But if you want to buy some time replace the spoke and put some liquid wrench on the spoke nipples and wait till they loosen up.  Mostly brakes tend to stick because of old cables/housing.  Replace the cables first.  An easy way to check the chain is with a simple ruler.  Any rivet to a given rivet should be at or no more than 12 1/8 in.  If it is more, throw the chain away and get a new cluster.  As an aged ex bike mechanic, I have noticed a tendency for these days for shops not to fix stuff but rather to replace and sell new stuff.  Thus their eagerness to sell you a new wheel.


Where do people in Netherlands wash their bikes? This would seem to be an absurd question, but I would like to know (especially from the Dutch or people staying in Netherlands) where do they clean their bikes? I am talking about:

a) Cleaning bike that's badly covered in mud / sand.

In Netherlands there are not many trails, but there is a wonderful beach nearby. I would love to ride on the beach but won't because I am staying in an apartment that has an extremely small bathroom and there is no balcony / terrace that I can use. I would not like to choke the bathroom outlet with too much of dust and dirt.

b) During rainy season after a few rides where to rinse the bike with normal clean water?

My situation:
I do not have the facility to use a water spray / jet spray that I can for cleaning my bike on the pavement outside my apartment.

My bikes
I own an MTB currently and am soon planning to buy a nice road bike as well. Despite what bike I own I love it and would like to keep it in the best possible condition.

People in Netherlands are passionate about biking and often ride good road bikes, and I'm sure the enthusiastic riders would've also definitely have faced such situation while caring for their bikes.

I am looking for some useful ways of cleaning here.

I use a portable weed sprayer with warm water in it.  Like one of these - Portable Pressure Sprayer.  They aren't high enough pressure to cause problems to bearings and light enough to carry up and down stairs in an apartment building/small enough to store under a kitchen sink.


short cranks for new Brompton JIS bottom bracket The bottom bracket on my new Brompton is this one (I believe):
http://www.sjscycles.co.uk/brompton-bb-cartridge-jis-for-spider-crankset-119mm-prod31207/

It is a JIS BB with 119 mm spindle length according to the description. The bike comes with 130 bcd chain ring/right crank, the crank length is 170 mm. I now want to use a shorter crank, 165 mm or shorter if available. So what cranks out there that I can use? The current crank is a single chain ring. Ideally, I want to just swap the cranks and use the current chain ring.

It seems to be fairly straightforward, I found a number of links around the web to people who have done it. Any crankset can take a single chainring, just make sure you mount it on the correct side of the spider when you do the swap. Try to match the existing chainline.

You may need to change the bottom bracket to maintain chainline and crank-frame clearance, but none of those links mentioned it as a problem.

FWIW I'm 180cm tall and run 150mm cranks on my commuter because they were the shorted I could get without paying silly money. They were the same price as cheap standard cranks. Unfortunately they're also made of low-quality aluminium and have bent somewhat in use. If you're strong or heavy I suspect the same may happen to you, but a Brompton is sufficiently flimsy that it may not be an issue (you might not be able to apply enough force without breaking the bike). IMO the best solution is to wait until it happens and buy more expensive cranks then, rather than paying up front when you might not need to.


Should I wait for clear views of the sky before turning on my Garmin Edge GPS? I have a Garmin Edge 200 GPS unit. I commute from the center of Melbourne CBD, where there are many tall buildings and not a good line of sight to satellites. I park in an underground garage, so there isn't an option to turn on the GPS for a few minutes before I set off.

I've found through experimentation that if I turn on the GPS as soon as I start riding, it takes longer to get a satellite lock than if I wait until I have clearer views of the sky and then turn it on.

So if you consider the first 5 kilometers of the ride, if I turn it on at kilometer 0, it can be 5 kilometers (or even longer) before it gets a lock. But if I turn it on at kilometer 2 (when I'm clear of the tallest buildings), it will get a lock almost immediately.

Is there any basis to my experience? Am I better off waiting until I'm a bit clearer, or is there another strategy I can use to try to capture my entire ride?

Update:

I've experimented with a few things, and have found that the most reliable method seems to be to turn it on and then not move until I get a fix. This works quickly regardless of the buildings around me. It seems that temporarily blocking a satellite by moving makes it take a lot longer.

I don't have any experience with that particular unit, but I do have a Garmin Oregon 450, which is a "hiking" GPS, but I find it works great for cycling.  I've found there's 2 important things to getting a lock on satellites. First, as you mention, is a clear view of the sky. The second important thing is don't move.  The faster you are moving the more difficult it is for the unit to lock onto a satellite.

The best advice is to turn it on before you ride and wait until it has a lock before you start riding. I've found that I don't really need a view of the sky, as I can turn it on in my house or in my garage, and get a signal no problem.  I can't however, turn it on in my office, where there's quite a bit of concrete around me.

I also find it helps if you turn it on in the last place you turned it off. I think the GPS assumes that it's in the same spot it was last time, and tries to lock onto the same satellites. I find if I travel with the unit turned off, it takes longer to get a signal when I do turn it on.  I don't know if this is how it actually works, but this is how it seems to work for me.

Signal is also affected by where you are on the earth.  It works better when you're closer to the equator. You're in Melbourne, which isn't close to the equator (-38 degrees latitude, but a little closer than I am up in Canada (45 degrees latitude).  I don't think you're far enough that it should be a serious problem.


Options for a super-compact crankset for touring (replacing Shimano 105 crankset) I plan to use my new Canyon Endurace AL (11-34, 52/36) for some touring and I'd like some slightly more pleasant gears as I'll be carrying some weight (I have a tailfin rack I'm using with it) up some hills.
My ideal setup would be buying a 46/30 crankset for around £100-£150 which I could just swap in when touring (a couple weeks a year) (readjusting the front derailleur of course) and swap out when doing normal riding (95% of the year). I realise I'd also probably need to swap over the chain or shorten it each time.
Are there any such 46/30 or 48/31 cranksets that would work with a 105 setup and standard Shimano BB? I wouldn't want to change the BB over each time. I saw the RX600 but assume this would need a new FD as well due to the chainline difference. Are there any hacks to make it work? Are there any parts in Shimano's lineup that could help - I don't mind if it's not perfectly permitted by Shimano, just need it for a couple weeks a year really.
If not, I guess my options are just to switching the chainrings down to 50/34 - a small decrease of about 6% vs 17% for 46/30 but better than nothing. Would that be just a case of buying two new chainrings and installing them?

I assume your current crankset has a 110mm BCD? You could go down to 46/33 teeth. (example 33 teeth chainring: https://www.bike-components.de/en/TA/X110-Chainring-4-arm-Inner-110-mm-BCD-p46803/)
The Shimano RX600 crankset puts the rings and pedals slightly more outwards. It might work with a normal road front derailleur, otherwise (officially) you need a GRX front derailleur.
I’d rather go for a traditional width, something like the FSA Supercompact with 46/30t.


How bad is this broken brake cable strand? I just bought a new bicycle. While I was fiddling with things (removing tags, mounting a light, etc.) I noticed that the boot on the rear brake cable was loose. When trying to reseat it, I found that one of the strands of the brake cable was broken, and poking through the boot. Furthermore, the cable is un-twisted just before the bolt that clamps it to the right side of the brake. These seem like very bad things to me which I should immediately get fixed (and complain about). Am I correct? Is the bike unsafe to ride?

I wouldn't say that a single broken strand on a new brake cable would render the bike "totally unsafe to ride," but if it is an option you should bring it back to the shop and have them replace it. This might be a sign that whoever put this bike together or inspected it for sale doesn't have a very thorough shop ethic. If they were careless enough to install a brake cable incorrectly, there may be other - more serious - oversights which can add up rather unpredictably. Not totally unsafe, but not ideal for a new bike.

In any case, brake cables are cheap and should be replaced at regular intervals.


Suspension Maintenance How often do you need to have your fork and rear shock fully serviced?  My guess is that this depends on how many miles you are riding, so lets say 150 miles/ year.

Most fork manufacturers will actually suggest service based on Hours on the fork, I know Fox will suggest you breakdown and clean all seals and replace open bath oil systems every 30 hours ridden.  Also most sealed gas dampers suggest you send them back to the manufacturer every X number of hours to have them rebuilt by the factory.


9s rear deraullier with 10s chain I have a 9s rear derailleur in a 10s transmission. It works fine, but I have concerns about if this configuration could produce problems in the long term.

I know the 10s chain is narrow compared the 9s chain, but it fits properly in the wheels of the rear derailleur. But maybe I'm not taking into consideration other aspects.

If your cassette is 10 speed, you need a 10 speed chain. The derailleur will be fine.


New Continental Hardshells Having difficulty bedding my new Gatorskin tyres onto the clincher wheels of my audax bike. Campag Scirrocco wheels. There is a constant 'dip' in the tyre at the same point despite numerous reinflations.

Continental tires have a tendency to do this, especially when new. It's very common. Put some soapy water on the bead and temporarily overinflate. That will usually get them to seat.


Change-over rules for women's team sprint I have just been watching the women's team sprint finals, and sawsaw China lose the final race due to a rule infringement. Earlier the Great British team were disqualified for the same reason. There is a set region that one rider has to peel off and let the other pass through.

Despite the commentators' best efforts I still don't understand where this region is marked on the course.

Also I don't understand why there is such a rule at all. The lead rider allows the second rider to draft for the start of the race, so they want to stay in the race as long as they can, but they wouldn't want to stay in until the end. Is there a reason for a fixed change-over zone (e.g.safety), or is it just a rule that's always been part of the sport?

The rules for Track Races are here. In the Team Sprint:

  The leading rider shall lead the first lap and move towards the outside of the track and then drop back to leave the track without hindering the other team.

In Great Britain's semi-final this is what happened at the end of the first lap:

Jess Varnish (nearest to us in the picture) was the leading rider with Victoria Pendleton as the second rider. Jess Varnish should have lead for the whole of the first lap, unfortunately Victoria Pendleton overtook her before the first lap was completed and they were disqualified.

The same thing happened to the Chinese team in the final.


At what time of year can I buy a bicycle for the best price? Is there a month when new models come out and dealers discount stock like with cars?  Do they raise prices in the spring and lower them in the winter?

Probably not what you're looking for, but... if you live near a college campus and are willing to buy used, the end of May might be a good time to check Craigslist.


Removing the return spring of a rear derailleur I am trying to turn my standard shifting bicycle into an automatic shifter using a motor to increase and decrease the tension in the shifter cable. The problem is that a lot of torque is required to do this, so I was considering cutting the return spring off.

I know this is permanent, so I want to make sure that I am doing the right thing before making the cut. I am planning on installing a spring with a much lower spring constant on the cable itself (see image).

This is another thread with a similar topic. Móż suggested cutting this spring.

(Automatic Bike Project) amount of torque required to change gears?

I am really new to bicycle engineering, so please excuse my lack of knowledge on the topic.

It is called the return spring.  Without that spring you don't have return.

Without a return you would need a push / pull (stiff) activator.

Looks like commercial electronic use a cable (pull) activator.


Reinforced Shimano pin snapped before connecting chain - how to resolve? My previous chain snapped weeks ago and only got a new one sorted.

I've cut the chain to the right size, fed it through the derailleurs and onto the bike correctly.

The last step was to use the reinforced Shimano pin to connect the new chain together.  Unfortunately the reinforced pin snapped as it was being put into its slot.

My wife was doing it so I'm not 100% sure what happened but she said it snapped very easily and unexpectedly. My only guess is that the chain tool wasn't going straight?

Anyway, the actual link that you'd want to stay in and connected, wasn't far enough in yet so it fell out, the 'snapping' bit is now stuck pertruding out of the chain.

I've never replaced a chain like this before so I'm slightly weary of doing damage.  It'll be tricky, but should I be able to use the already snapped pin to connect the chain and hopefully it'll help push out the snappable portion?

Should I attempt to get another reinforced pin instead of attempting the above and start again?

I could attempt to pull out the 'snappable' portion with pliers but again slightly worried about causing damage!

You can often use the chain tool to drive the half-way inserted pin back out from the chain. I do not think it is advisable to attempt pressing it in again. It is certainly possible, I did re-pressed regular roller pins a couple of times when I or someone else accidentally pressed them out too far so that they fell off. It is not the most enjoyable experience, especially as the roadside repair.

You can get another reinforced pin and try again. Alternatively, you could get a so-called master link which replaces one of the half-links on the chain (presumably one at the end of your chain with the broken pin sticking out of it). The master link allows to close the chain using no tools at all, and often to open the chain using special pliers (or just bare hands, with enough swearing).

Several companies manufacture such links for chains of different widths (for cassettes from 8 to 12 speeds). They are generally compatible with chains of all vendors, e.g. you can use a KMC master link on a Shimano or SRAM chain with no issues.


Cantilever brakes for older narrow fork bosses (55mm)? I have an 80s cyclocross frame I am restoring. The fork's cantilever bosses are spaced at 55mm - much narrower than the modern standard (around 70mm I believe).

I tried to fit a pair of Tektro CR-720s, but despite using thinner pads and removing the spacers cannot get the pads to square with the rim.

Can anyone recommend a set of modern cantilevers (preferably wide profile) alternative to Mafacs that they known to work with this narrow spacing?

I'm hopeful the Dia Compe GC-999 might do the trick as they seem to be based on a traditional design.

I also e-mailed Velo-Orange and Paul Components as I thought they had cantilevers that would match, but they claimed theirs don't work at this narrow spacing.

What brake pads did you try? I had a heck of a time getting modern Tektro cantis working on a fork of mine until I used Kool Stop Thinlines with the spacers set for in their thinnest configuration.


Which durable Chain Breaker? I bought the cheapest chain breaker, XLC 10EUR, and its head got loose on the first try (maybe due to my poor handling or it is not well-done product).

I was on the journey and had to get it so did not have time to investigate for better long-term option. This reply raised the issue again, here.

The shop-keeper said that he used some very expensive tool because it "is much better in everything but for great price tag". Which durable chain breaker would you suggest to replace XLC? And if you have tips not to break it, please, do not hesitate to contain.

I use a park tool breaker in the shop, but when I'm on the road it's nice to have something very small and light. The Cutter Shorty is a packable bike tool that includes a chain breaker. While not quite as easy to use as a park tool, it's perfect for packing with you. That and a spare master link, and you're set.


Is it safe to ride with bent fork? My bicycle went from this when I bought it:

To this when I crashed (note the front fork bent where it attaches to the stem; front wheel almost touches the down tube):

Update: Just looked at the frame and saw cracks in the paint on top tube and down tube.

besides the structural issues, looks like this crash has changed your bike geometry rake, head angle, tail, and wheel base.  This will likely result in much more sensitivity to handlebar input.

If you can, I would advise against riding the bike, particularly on low traction surface since a small jerk can put it a handle-bar lock and you into an endo.

As others noted, the clearance from the down-tube is also cause for caution.  The steel fork can likely be bent back, provided that there are no frame fractures and wheel damage (hard to imagine the wheel being perfect with forks bent).

otherwise, it doesn't seem likely that the steel bike would disintegrate as you're riding.

good luck


Rim shot? Goes badly out of true at medium tension I am pretty sure this rim is shot, but wanted confirmation and/or a better understanding of what's up. I'm fixing up a donor bike that was pretty apparently stored outside for years. Despite that, many of the parts are salvageable -- so good in fact that I decided to just overhaul the bike rather than part it.

Except the wheels? Rear wheel was pretty badly out of true. So I put it in my stand, tested the spoke tension, it was all over the place on the drive side, from 80-140 kgf. Non-drive similar, but not such high tensions. I began backing off the spokes and trying to get drive side to about 105 kgf, non-drive about 65, and the thing got worse.

I backed off all the spokes until they were slack. The rim (a 23mm wide, 32-spoke aluminum with plenty of brake track, BTW) looked fairly straight. I had expected it to show evidence of being badly bent, but it looked no worse than plenty of wheels I've gotten nice and straight.

So, I began tightening again, moving up slowly. Probably 5-10 kgf per side. (It was tedious.) As soon as I got the drive side up to about 55 kgf (non drive would be about 17 at this point I guess) The thing started to pringle badly again. That's with tensions nearly perfectly even on each side. The rim's easily 1cm out of true.

I'm convinced this thing is a goner (not surprised given its history) but I've never seen a rim behave like this. Maybe all that weathering and corrosion has just made it completely and randomly unstable? I was thinking maybe the eyelets were failing in some spots, but of course, if I had eyelets failing or weak spots near holes, I'd see the move reflected on the tension. I don't. I get even tension and a really warped rim.

Anyone seen this on an old rim?

Yes.

Once the rim has taken a set (ie it is really bent), you can only true it so far with tensioning spokes.  Too much tension will strip nipples, or can even snap spokes outright.

You did right by backing off all spokes till they're all loose.  Then use brute force to "straighten" it once you've identified the areas of the rim that are out.  A large flat surface helps, or another rim that is known to be true.  Flip things over and over, use elimination to identify the bad spot/s.
The straighten the curves.  This is sometimes done using a street drainage grate as a lever or plain old stomping, like this:

As long as you can pressure the high and low spots and make it "flat" then it could be trued from scratch.

If its really dead, then its dead.

However you say the rim looks fairly flat with the spoke tension all slacked off.  That's puzzling, and I'd recommend a close look at the rim nipple holes.  Could be some of them are a bit softer metal than you might want, and they're moving under pressure.  Also check the hub end of the spoke to see if there's any damage to the flange.

Unless there's something really good about the wheel, it can suck up a lot of time and still come out with a sub-par wheel.

I have about 4 spare wheels for various bikes - as you come across good ones, then keep them.

I have a seriously dodgy wheel where one spoke has no tension at all.  It goes out of true if I so much as finger tighten that one spoke.  Its perfectly ride-worthy for me, but I'd not put it on someone else's bike without fully sharing the problem.   As a rim brake wheel, true is more important than spoke tension.

Separately, I've wasted 4 hours trying to true up a front wheel for a give away.  In the end I swapped the hub and spokes to another rim, and got the assembly and truing all done perfectly in 30 minutes.


How is the finishing stage of truing a laced wheel improved by adjusting spokes in groups of 4? The finishing stage of truing a laced wheel
usually consists of fine lateral adjustments
yet those meant to remove
the last perceptible errors often create
almost equal errors elsewhere on the rim.
These new errors include both tracking and spoke-tension inconsistencies,
even when spoke twisting has been scrupulously avoided
and the rim /spokes have been reconditioned by
overstressing and relaxing them after each adjustment.

This can be frustrating even if spokes are adjusted
in left-side / right-side pairs as suggested
in the section Lateral Truing on page 102 of
The Bicycle Wheel, Third Edition, by Jobst Brandt.

  Lateral Truing
   · · ·
  To correct a lateral error, tighten spokes in the error zone
  from one flange and loosen ones from the opposite flange.
  If the wobble is to the right, loosen the spokes on the right
  and tighten those on the left.

Some bicycle mechanics minimize fine-tuning surprises
by adjusting spokes in groups of four.

How is the finishing stage of truing a laced wheel
  improved by adjusting spokes in groups of four rather than in pairs?

(This is a
 leading question
 and as such has been
 answered by its poster.
 Feel free to improve that answer or add another.)

Note: This pertains to laced, not radially spoked, wheels
because a radial spoke applies no torque to its hub.

When truing a laced wheel, adjusting spokes in groups of 4
eliminates distortional side effects that would otherwise be relayed by
hub torque to all other spokes.

Hub torque is a turning force between hub and rim,
generally recognized in two main forms
where the rim has a tire that contacts the road.

Pedaling produces a driving torque on the rear hub.
A disc or drum brake produces a braking torque on either hub.

This is explained in
The Bicycle Wheel, Third Edition, by Jobst Brandt,
beginning with the section Torsional Loads on page 22.
Three pages later,
Figure 11 exaggeratedly displays a typical complex of rim distortions
produced by hub torque
as half of the spokes experience increased tension
while the other half experience relaxation.

  Torsional Loads
   · · ·
  Spokes [. . .]
  transmit torque from the hub to the rim by becoming tighter and looser.
   · · ·

The converse is also true:
spokes’ tensions transmit torque from rim to hub.
Although a wheel being trued has no road to fight against,
its hub is nonetheless torqued relative to the rim,
by each and every spoke.

Spokes are commonly adjusted in rim-adjacent pairs
so that lateral or radial corrections
do not become, respectively, radial or lateral distortions.
This works well near such a pair spokes but the adjustment
often changes their combined hub torque enough to distort the rim elsewhere.
One example is a lateral rim adjustment made
by tightening one spoke while loosening its neighbor.

The preferred adjustment with four spokes includes
two additional rim-adjacent neighbors.

As spokes that are two holes apart on the rim
connect to symmetrically placed holes on the same flange,
equal adjustment of those spokes produces no combined change in rim torque.
Adjusting each spoke in this 4-wise group
half as much as its corresponding spoke in the pairwise adjustment
produces the originally intended rim correction,
as would be hoped, but without creating new errors elsewhere.


Mini-van for bicycle I realize this is on the edge of asking for a "product recommendation", and is also likely to be viewed as "off-topic" by some because it's not directly about bicycles, but I need to get a new motor vehicle (both because the old one is about to fall apart and because the new house where we're now living has a uncomfortably tiny garage).

So, what attributes should I look for in a vehicle?  Would be nice to have one that could carry my road bike in the cargo area (removing the front wheel if necessary), but it needs to be several inches narrower than my current enormous Honda Odyssey.  I don't really want to haul my bike to every auto dealer in town to see if it fits, so some clues as to "fit" might be good.

And, if no specific recommendations, you might suggest one or two to avoid entirely.

(Note that this is in the US.)

If its just yourself and one road bike, it will fit into the back a majority of hatch back style cars. With the seats folded down and front wheel off, you would be surprised how much space even a compact has.

Look for a car that suits you best then make sure the bike fits. As far as putting the bike in, look for rear seats that fold up quickly and easily, a wide rear hatch opening with a low sill would be important to me. A front passenger seat that folds forward (if a small car) might help.

Another option is some cars allow the rear seats to fold up, meaning the bike could be carried in the rear passenger foot well.  In this case you may want a chain cover to prevent oil getting onto the cars interior.

Consider how much time the car is used as a bike shuttle vs other uses and balance the the convenience and costs.  For instance a large car that you can leave the wheel on is more convenient but probably costs more to own and run, a small two seat sports car while  cool to own,  is not very convenient if you have to take front and rear wheels off to carry the bike.


How often do you need to lubricate alloy seat posts I own two tourers which I normally relubricate their aluminium alloy seatposts every spring with high quality grease. Due to moving to Cambridge and the coronavirus outbreak, both cycles are being kept safe 10 miles away but if I miss this lubrication will their seatposts become seized?

No they won't. It is often enough to lubricate once when the bike was built unless it is used/kept for a very long time. Especially if the bike is kept in a dry place. It is not necessary to lube it once a year. The lube stays there and protects the interface for a long time. If you pull a bike that hasn't been used for ten years from a shed, many things could be seized but even then seizing of the seat tube is far from guaranteed. It is even unlikely if it was well conserved before the storage.

Interface of two different metals could change it due to electrochemical potentials and rusting. I assumed aluminium alloy on both sides or steel on both sides.

Just do it the next year or when you get to your bike.


What are the pros and cons between an aluminium and carbon frame? I'm after a mountain bike and I've narrowed it down to the Cannondale F29 (based on reviews, plus I like the look of the bike).

My question is, should I go for the carbon bike or the alloy bike?  I'm 6'4" and weigh about 125kg; I know carbon is very strong but I've heard when it goes, it just snaps (rather than alloy that bends).

Do you think this is a valid concern?

What are the pros and cons of each?

Carbon is seen as expensive and light while Aluminum is heavier and cheaper. Both are, to all practical purposes, more than robust enough for the job. At the price point you are looking at (for a hard tail), Carbon is a no brainier and superior in every way.

If you are worried about failure mode, both are as likely to fail catastrophically as each other, although for different reasons. Aluminum will fatigue and stress crack then fail, while carbon tends to fail from impact damage.

Do not worry about the frame failing, it happens, but to be honest, I have seen plenty of guys in bandages, casts and hospital with fully ride-able bikes, and have never personally met someone who got seriously injured breaking a frame.


Converting from square spline to external bearings, what do I need to know? I need to replace the entire drivetrain on my circa 2000 MTB commuter. Quality groupsets all seem to use external bearings these days. Replacing my current cartridge bottom bracket for a modern external bearing BB is my main compatibility concern. What information do I need from my frame and a prospective groupset to determine if it will fit my bike?

Off the top of my head, I guess I need to know my frame's BB shell width and thread and the chainline. What else? Where do I find the corresponding info for the new parts, particularly Shimano? Anything I need to look out for?

Update:
The bike needs new a new bottom bracket, chainrings, chain, 8speed cassette and front derailleur. Replacing them individually costs almost as much as a complete modern groupset (which includes new levers, rear mech and two more gears).

Why not buy a new bike? Three reasons. One economic: the steel frame is sound, the wheels and brakes are new, and bikes of comparable quality are much more expensive than a new groupset. One philosophical: I don't like throwing things out while they still work. One emotional/irrational: I like my bike, it's been good to me, and I want to do right by it.

You actually guessed the only thing that you really need to watch out for: the BB shell width. And you don't even necessarily need that until you're actually putting it all together. Almost all BB shells are 68 or 73 mm. Most of the external BB's come built for a 73 mm shell and include a spacer for a 68 mm shell.

The odds are really really good that the threads and diameter coform to the British I.S.O. standard. If you have reason to think that your bike is non-standard, I'd recommend taking it to a shop and they can tell you what you need.

Unless your mountiain bike is a single speed, you don't need to worry about chainline. They're pretty standard and a derailleur adjustment will take care of any deviation from your current setup. If it is single speed, the BB isn't where you'll be looking to get that right. It's not like a cartridge-style BB where you can just get a different length spindle. Instead, you move the chain rings to the inner or outer side of the spider and/or mess with spacers in the rear wheel.


Discrepancy between old chain length and largest chainring largest cog method Putting on a new chain.  First counted the links on the old chain - which I never had reason to think was the wrong length. But since I felt like being thorough I also measured using the largest cog to largest chainring method.

Largest cog to largest chainring comes up with a measurement 7 links shorter than my old chain.  Advice on which to use?  Is it possible my old chain was too long and I just never noticed? Don't want to end up with too short a chain.

If you are counting links it’s easy to mess up, but it is possible your chain was too long if your rear derailleur had extra capacity to deal with the slack (but not 7 links I think).

Determine chain length using the method in the video below, mark the rivet where you would cut. If you do this properly, making triple sure the chain is on the biggest ring and sprocket, you will not end up with a chain that is too short.

Lay the chains next to each other to compare lengths instead of counting links or rivets.


Avoiding hydraulic brake system overfill when bleeding with worn pads I have limited experience with bleeding Avid Elixir 5, Shimano SLX and cheaper Shimano and Tektro brakes. I usually time the bleed just before brake pad replacement, in order to avoid the risk of contaminating the pads (because a rotor can be cleaned, but pads cannot).

The problem is, when I replace the pads with new ones, the disk rubs. This necessitates shedding brake fluid until the caliper pistons are allowed to move far enough back. The problems with this are:

risks introducing air to the system, because I use the lever bolt, instead of the caliper bolt
risks shedding too much liquid and voiding the bleed
it is tedious

Is there a trick to bleed the system just correctly, while mounted on the bike, with fully worn brake pads?

The problem you are encountering is likely because the pressure during the bleed process forces the pistons out slightly - this means that in effect you overfill the system.

You are best to push the pistons back fully with the old pads in place, then remove the old pads and replace with a bleed block.

You can buy specially designed bleed blocks, or you can see how to make your own here:http://www.epicbleedsolutions.com/blog/how-to-make-a-bleed-block/


3x increase in endurance in 3 months? I am currently using a hybrid bike, which weighs about 10kg (quite light for the category I've heard), and my longest ride has been 65km at an average of 18km/h in a mostly flat terrain.
In this ride for many kms I had a big muscle pain in my legs; by the end of the ride, stopping at traffic lights was extremely painful. Also, it took hours at home to go from huge pain to just normal muscle pain. I do not think I could have gone even one kilometer further.

I was pedaling at a good cadence, aiming for 90rpm. At no moment I felt like instant burning in my muscles; I would choose easy gears to keep me in high cadence and light strokes; it felt relaxed. But still, after 35km I felt 'loaded'; after that the pain started to increase more and more.

I will participate in a race of 180km with a time limit of 9 hours (so I need 20km/h and I am fine with finishing in 8h59m, I just want to finish), 3 months from now.

So I roughly need to go a little bit faster and improve my endurance 3-fold in 3 months.

My current plans for improvement are (my bike is 500$ Giant Escape; nothing fancy):

Buy clip-on aerobars. This should make me reach the speed I need, the terrain in mostly flat.
Buy clipless pedals. To help me use different muscles. I do not know how much would this help with endurance. I hope 10% or so.
Buy energy gels, I did not feel like I was lacking energy but I guess they will help. And on the race day I'll need them for sure.

What other gear, training techniques, and race day tactics can be used to improve endurance quickly?

If you did 65km (40 miles), then after recovery (maybe 1 week) you can probably do that distance again with much less discomfort.  You should then be able to increase your mileage about 10-20% a week, if you get in one max-length ride and one about 1/3rd shorter each week.
Conveniently, I've found that you can usually, if you push yourself, ride about 50% farther than your "accustomed" ride (though you will be dragging at the end).
You do need to eat and drink on a long ride.  I'm a big advocate of this stuff called "food" for that (hopefully provided for you on your ride), though it doesn't hurt to have some sugary snacks.  And did I say DRINK?
90 RPM is probably a hair too fast.  But you do need to keep your cadence up, especially as you begin to tire.  20k/h (12.5mph) is not a terribly fast pace (even allowing for rest stops), so it's important to not burn yourself out trying to maintain a fast pace.

Ultimately, for 180km (112 miles) you will be running on empty near the end -- that distance is challenging.  But by slowly working your endurance up you can probably make it.  DON'T expect to do it with "tricks", though -- the most important thing to do is to just steadily increase your distances.


MTB Shimano MT610 crankset with 32t: possible switch to 30t? I'm looking at the Raven 8.7 with its Shimano MT610 crankset with 32 teeth. The bike comes equipped with Shimano SLX M7100, 12-speed cassette and Shimano Deore XT M8100, 12-speed rear derailleur. I would need a more favourable ratio for the climbs so I'm trying to make sure the original 32t chainring can be swapped with the 30t version.
Here's the manufacturer's page (https://bike.shimano.com/en-EU/product/component/slx-m7100/FC-MT610.html).

How can I be sure I'll be able to swap the 32t chainring with a 30t one?

Yes, you can swap for a 30T chainring. The Shimano page (link you provided) states that the crank arm is compatible with a 30T ring, and they provide a link with a part number (Y0K430000) to the exact Shimano chainring that would replace your 32T.


Shimano 105 crankset Been reading from posts and can’t find my answer. Any help would be appreciated.

Scenario: I currently have a Felt AR5 10-speed with shimano 105 rear/front derailleur, 105 levers & brakes and a FSA crank 50/34 compact. I will like to change the crankset to 105. But I believe the 105 is only a 11-speed type crank.

Question: will the shimano 105 11-speed 52/36 crank work in this scenario? And what bottom bracket would be needed (BB30 or BB60 English). I would still run with 10-speed.

Thanks!

The width difference of 10 and 11 speed chains is very close (5.88 vs 5.62mm) so usually this works without issue. There is always some possibility that even this difference will cause rub against the large ring in some of the small/small combos. Very short chainstayed bikes like yours increase the likelihood. Chainring micro spacers such as the 0.2mm FSA are the fix if there are issues. You'll also need to make sure your FD can be moved up a little, but that shouldn't be a problem.

You haven't said what kind of BB shell your frame has. If it's threaded you need any ISO/BSA threaded Shimano road bottom bracket. If you've got FSA cranks with a 24mm spindle now then you can use your existing BB if it's not worn out. If it's BB30 you have the option of using any of the myriad adapter systems for 24mm cranks, which consist of reducer bushings, press-in shell adapters, and screw-together adapter bottom brackets. There are many questions here about the pros and cons of these systems. Your bike's cable routing arrangement in some cases can inform which is best.


What is the most efficient way to ride up or down hills, and into or away from wind? I'm trying to work out how hard I should push myself when riding up or down a hill. Similarly, how hard should I push myself when riding into, or away from, or perpendicular to wind?

My aim is to arrive at a location in the shortest amount of time possible. I would assume that if I output more power going up a hill, then I would have to compensate by outputting less power going down the other side (let me know if you disagree). So, what is the most efficient way to achieve this aim? Is it better to work harder (and save time) up hills, or work harder (and save time) down hills. Similarly, how does wind affect this, both on the flat and concurrently? For the purposes of this question, assume I am riding by myself and hence ignore slipstreaming

Extra points for justification of your answer with links and/or physics. (N.B. there are no extra points.)

As you have guessed, it is better to work harder on the uphill and rest on the downhill. And as others have mentioned, whatever works for you on the uphill in terms of balancing high cadence and mashing is best. However, there are a few guidelines that you can follow to approach each situation in the most efficient manner possible.

Downhill: Since wind resistance is the biggest factor in reducing your speed in this situation, you simply want to be as aerodynamic as possible. Tuck yourself into an aero position. Basically, you want your upper body as low and horizontal as possible. Check out pro riders on the downhill of a mountain for visual aids. Use this opportunity to rest and only pedal in short bursts coming out of corners that you've had to brake for.
Headwind: You want to maintain a somewhat aero position, so keep low. However, a complete aero tuck compresses your lungs in your abdomen and you can't breathe as fully as if you were sitting straight up. This means you'll need to find a balance between aerodynamics and being able to breathe efficiently while keeping up a constant cadence and pedal force. You'll also want to keep your arms farther apart because tucking them into the center also compresses your lungs within your chest. Most likely, you'll want to either be in your drops or hunched over a bit with your hands on the hoods.
Uphill and/or tailwind: You can pretty much treat these two the same way since wind resistance is less of a concern than your own aerobic fitness. Just sit up and keep your hands wide to keep your lungs as open as possible and pedal with whatever force and cadence works best for you. Studies confirm our everyday experience that standing while you pedal will increase your speed but is not sustainable for very long. You'll only want to stand up to maintain speed over short sections where the road rises steeply (or more steeply if you're already on a hill), when a brief gust of wind has slowed you down and then let up, or any other situation that briefly threatens to lower your otherwise sustainable speed. If you're running out of energy and only halfway up a hill, standing up won't help you.

Of course, in the real world you never have just a hill or just wind from the front or back. There are cross winds, cross-head winds, cross-tail winds, hills with wind from any direction, and everything in between. Add in traffic concerns, road conditions, etc., and you'll almost certainly have to find a balance between pedaling efficiency and dealing with the world around you.

If you'd like to read more, there is a great article on cycling up and down hills: http://www.sportsci.org/jour/9804/dps.html.

And the ever helpful sheldonbrown.com has an qually excellent article on the effects of wind resistantce here: http://sheldonbrown.com/brandt/wind.html.


How should I alight from the pavement? Whenever I'm exploring a new bike route or climbing a steep hill, I often need to get of the road and onto the pavement to avoid motorists, pushing my bike on the pavement until I feel it is appropriate to join the road again. I look left and right for passing cars, but I feel that I might be doing something wrong.

Is there a  signal I should use when I wish to join the road and is there anything else I must take into consideration regarding how and where I alight?

Depending on what you mean by "should", you possibly "shouldn't" be riding on the pavement.

After parking or walking on the pavement, I move back onto the road in a way that's similar to setting off from/in a parked car.

Stand on the pavement/side-walk, side by side to my bike.
Lift the bike down onto the road, close to the curb, facing in the correct direction (i.e. with the traffic)
Look to make sure there's still nothing coming.
Mount the bike (standing on the side-walk, holding the brakes, swing one leg over and sit on the saddle, with the other leg still on the side-walk)
Now I'm on the bike, and the bike is on the road: stationary, and at the curb, and now ready to move off when traffic permits.


What hanger is compatible with Shimano Claris RD R200? Trying to find a rear derailleur hanger that works with the Shimano Claris R2000 8 speed, on my REI Co-op bike. Have done  lots of searching on Shimano's site and Amazon and Google. What am I missing? I think Shimano doesn't have branded/proprietary  hangers; if that's the case, how can I find another brand of hanger that I know will fit?

If helpful, the bike specs here: https://www.rei.com/product/106309/co-op-cycles-ard-11w-womens-bike.

Derailleur hangers are specific to the frame, not the derailleur. Do you not have a hanger at all or is it just broken? If it's broken, then it's usually not too hard to find a matching aftermarket one from Wheels Manufacturing or derailleurhanger.com. Have you contacted the manufacturer to see if they sell it separately?


Peloton Trainer - what style of cleats are used? I was wondering what cleat standard is compatible with the Peloton Trainer ?

What cleat standard is installed in the default configuration ?

Actually, IT DEPENDS. Peloton sells a home version that uses LOOK and a commercial version (to most hotels and apartment buildings) that cannot use a LOOK but that have a shoe-cage on one side and an SPD SH51 clip on the other side. Most Peloton reps do not seem to know this (for all the money they charge you think the company would train its people...) so check your bike carefully. It might be easier to take a picture of the bike pedal and bring it to the bike store so you don't accidentally buy the wrong clips--or shoes. (Not all shoes take SPD and LOOK, many only take one type or the other.)


Which puncture-resistant tires? I commute on city streets and have had two punctures in 5 months: first a roofing nail, second a small shard of glass.

Punctures are a nuisance.

I've read some people recommend Schwalbe "Marathon" tires. A comment in reply to Are slick tires worth it for commuting? also mentions "Conti Gatorskins, Specialized Armadillos, Soma Everwears, et al."

Is there anything to distinguish one from the other? For example if an LBS stocks Conti Gatorskins should I say, "No, I'm looking for Marathons"? Or are they more or less equally effective (price and, more importantly but less easy to measure, puncture resistance and rolling resistance)?

My wheels are 700x32.

The Schwalbe Marathon Plus (not just the Marathon) is widely regarded as the most flat-proof tire out there. It's also heavy and expensive, but if your priority is avoiding punctures, I don't think it can be beaten. ISTR reading about a round-the-world rider completing 50,000 miles on a pair without a flat.

Specialized Armadillos are not, in my experience, particularly flat-resistant, although there might be a beefier version than the one I was riding on. I have no experience with the Gatorskins.

Anyhow, there are definitely differences between flat-resistant tires. There are even differences between Schwalbe Marathons variants.


Cons of using an infrequent use long range e-bike battery trailer using SLAs So I've recently purchased an ebike and started thinking about how I could go long distances without charging.

It occurred to me that whilst sealed lead acid batteries can't go through many cycles, for the odd long distance (~100 miles) some deep cycle ones could be perfect, especially if mounted within a trailer.

I have a 48v e-bike, so I'd need 4 SLAs in series. I'd probably only use this a few times a year so other than the discharge from using them they'ed always be topped off with charge.

Can anyone see any potential disadvantages of doing this? Perhaps SLA's are just too heavy and I wouldn't get the range I want?

Lead acid batteries are heavy. Too much extra mass, even in a trailer could to put strain on the motor and brakes. You'd have to figure out what the mass of  batteries you would need, and see if it would exceed the bike's maximum load specification.

Also, is it possible to run an eBike from an external DC power source?