Braking one-handed to signal down steep traffic-heavy slope I've just recently picked up biking and will be cycling to work when I start in a few weeks. One thing that's really bothering me on my route is a very steep hill that gets very busy during rush hour. At the bottom there's a traffic light where I have to turn right (I live in the UK, we drive on the left).

I've been doing the route off-peak to practice. Thus far it's been clear behind me each time, so I've just looked back and drifted right to position myself correctly before the right turn. However, if there's traffic behind me, I would not feel safe doing this manoeuvre without hand-signalling to the right.

Is it safe to just brake with my left hand on a steep hill? (I believe that's the rear brake on British bikes.) Can I initially brake with both hands then briefly take my right hand off to signal? I've literally never braked one-handed, so it kind of terrifies me. Sorry if these sound like dumb questions; I just don't want to get injured!

Thanks!

As an confident road rider I'd do two major things.

I'd turn my head, look backward and make eye contact with the driver(s) just behind me to show intention, and maybe signal at this point.  Or I might not signal at all.  Then
take the lane.  You will be moving fast enough to slot-in with the cars because of the downhill.  I'd avoid being sidelined on the side of the road.  I'd also do this well-before the intersection; hard to say how far but even 50-100 metres out.

If I'm needing to brake hard, I'll use both hands, and leave signalling/indicating out of it completely.  You've already shown your intent by taking the lane and moving closer to the center-line.

Since your experience is lesser, feel free to not do any of that.  You have to be comfortable with your intent and actions.  So instead you could:

Get off and walk this bit.  Brake early, loose speed from the downhill, and simply walk across the roads before the intersection.
If permitted, you could ride on the footpath, though the UK doesn't allow this unless it's a specific shared path.
Find another route to work.  There's a fair assumption that the best route for a car is also the best route for a bike, when frequently there are alternatives only available to bikes.

Also, if other cyclists traverse this intersection then watch and observe their methods.  If it makes sense then emulate them, and if not, then don't.


Can I use silicon spray to lubricate my hybrid cycle chain? Can I use silicon spray to lubricate my hybrid cycle chain? (Of course,  after de-greasing it using a de-greasing spray)

Thank you for your help

Can you? Yes. It is not optimal for use on chains though. It washes away rather easily leaving your chain unprotected and un-lubricated. It would work in a pinch but a light oil or something specifically made for the application will work much better and last a lot longer.

Wet or Dry lubes depend on the riding conditions and where you live. WD40 makes a good bicycle chain lube, their bike line, not the generic stuff in a can. Don't use that. RocknRoll, Triflow, ProGold all also makes good lubes.


Where to find specific vintage rim/wheel? I have a 1983 Lotus Unique that came with 27 x 1" Ukai rims. The front wheel went missing and I'd like to find an original replacement. Lots of 27 x 1 1/4" or 1 1/8" out there, but I haven't been able to find 1" rims. Any suggestions? Thx

A web search for “bike rim nos ukai” has some hits, but they’re very expensive and steel, which is undesirable in a rim. If you’ve got a historically significant bike you were restoring, it might be worth it. Otherwise, I’d recommend against trying to match the original.


How to use a single caliper truing stand (vs dual caliper)? I have used a Park Tool TS2.2 on a bicycle course. It has a caliper for each side of the rim. As you turn the dial, both calipers converge evenly toward the rim. This allows you to know which side of the rim has the biggest wobble, and therefore which side needs adjusting next.

Single caliper truing stands measure only one side at a time. Let's say the caliper is on the left. A 'peak' is detected on the left side of the rim, you tighten the right hand side spokes. I get that if you repeat this process the wheel will eventually be true, but you've only tightened right hand spokes. Won't the rim be pulled over to one side and have an imbalance with tense right hand spokes and loose left hand spokes? We were taught not to adjust either side more than 3 times in a row (When needed, the instructor would 'kick out' one of the calipers when he only wanted to use the other one, by wedging a screwdriver underneath the one he didn't want to use)- we would use both left and right caliper, therefore tightening both sides of the spokes, which would be more balanced.

So in my example with the single caliper on the left, the only way to detect 'peaks' on the right hand side of the rim would be to look for gaps on the left hand side, using the caliper as a visual aid. This doesn't strike me as very precise. The only other way being to constantly flip the wheel in the stand.
I think there's something critical and probably obvious I'm missing here, help would be very much appreciated.

When truing a wheel (such that the rim lies in a plane perpendicular to the axle) it is only necessary to measure against one side of the rim, as rims have a uniform width around their circumference (assuming there are no dents in the sidewall.

The other aspect of wheel geometry is correct dish (rim lies in a plane exactly halfway between the axle shoulders). Another question here indicates that the Park TS 2.2 needs calibrating to achieve correct dish. I believe most wheel builders use a separate dishing tool to ensure dish is correct.


Washing road bike with iron-rich water I was searching for information concerning washing the bike with iron-rich water, but haven't found anything so far. The water coming out of my garden hose is naturally rich in iron. I have cleaned couple of times both mine and my girlfriend's road bikes, but I noticed no problem. I was wondering if continuing doing so might have bad effects in the short and long periods. Is there anybody of you having experience with it?

Thanks in advance for the responses.

I doubt the iron-rich water will cause problems unless you put the bike away wet.

So, wash and then let it dry in the sunlight for a while, then turn the bike around and let it dry on the other side.   Or you could use an automotive chamois or a powered air blaster to help dry the bike off.


Can an individual gear/cog on the rear cassette be replaced? I'm trying to figure out how the rear cassette is put together, and I found this related question that suggests at least maybe the lowest gears can be replaced. I'm trying to figure out if in general any and all of the cogs in a rear cassette can be swapped out with new replacements should any get damaged or worn? I imagine some may be designed to be an all or none deal, but if one's rear cassette supports replaceable cogs what would be the giveaway to do a visual inspection for?

This question is also distinct from Is it practical to replace two sprockets on a cassette? where the focus is on practicality of replacement but not so much of how to discover if replacement is applicable to a given cassette. It's also distinct by relating to the whole cassette in general with respect to all of its cogs.

According to the late great Sheldon Brown, yes you can change an individual sprocket in a cassette, at least for Shimano.  Some cassettes have small bolts or rivets holding the gears together, but this is for convenience.

Most Shimano cassettes made in the '90s or later have a feature called Hyperglide (probably a registered trademark) that enables smoother shifts, by allowing the chain to engage two adjacent sprockets simultaneously.  Hyperglide works by giving each individual tooth a more complicated shape to facilitate shifts to and from each sprocket.  In order for Hyperglide to work, the adjacent gears have to be carefully matched to each other.  So if you change a sprocket for another sprocket with a different number of teeth, then shifts to and from that sprocket won't be as smooth.  But as Sheldon pointed out, that's what everyone was used to for decades before the invention of Hyperglide, so that needn't bother you.

I haven't been able to find anything on Sheldon's site about changing sprockets for Campagnolo or SRAM, but I would assume that those brands shape their sprocket teeth similar to the way Shimano do, and so similar concerns must apply for those brands also.

Personally, if a few of the sprockets in my cassette were worn, I would just change the whole cassette (and the chain also of course).  You're unlikely to save any money or hassle by just changing one or two sprockets, because the vast majority of bike riders change the whole cassette.  Most people who want to change just one or two sprockets want a particular combination of gear ratios for specific reasons.


How strong are pedals? Pedals are obviously a critical interface with the bike. A broken pedal axle would be catastrophic, most likely causing injury or even death, especially considering that pedal failure would really only occur during massive impacts. In light of this, is there a standard for how strong pedals and pedal axles have to be? Are road/XC pedals necessarily weaker than their burlier MTB counterparts? I've never seen a pedal marketed with a maximum load rating or anything. Pedal breakage, although rare, does occasionally occur for reasons other than manufacturing defects, so it is a valid concern.
Hypothetically (or in real life!), would I be able to safely ride a road pedal down Red Bull Rampage or some other similar event with gigantic drops and jumps?
What about other components of the pedal interface? The threads? The threaded insert in a carbon crank? How about the cranks themselves?

What about other components of the pedal interface? The threads? The threaded insert in a carbon crank? How about the cranks themselves?

I'll use the "pardo" durability index to answer. The durability index is based on the number of failures at http://pardo.net/bike/pic/index.html.
For pedals, we see three failure events.
For cranks, we see 55 failure events.
So it seems based on this that the crank pedal eye fails far easier than the pedal connected to it.
One reason is that the pedal to crank attachment has a design flaw, and the crank, being made of aluminum, is the component that suffers as opposed to the pedal spindle made from steel, a far stronger material. The design flaw can be seen from the left pedal having a left hand thread -- a proper design would not be sensitive to threading direction. It can also be seen from old cranks, from which the removal of pedals sometimes is a Herculean effort and even when it isn't, the pedal eye of the crank is visibly worn. The pedal to crank pedal eye attachment should have a 45 degree taper, similar to automotive lug nuts.
Of course, non-catastrophic failures of cheap plastic pedals happen often. Those are used only in inexpensive bicycles intended for little kilometers in their lifetime, for light riding.


Bike fitting for sore hands, Peugeot ~85 used as commuter I'm having problems with my Peugeot from ~85. I get sore hands quite fast when I ride it and it really feels like the pressure on my hands are too much (compared to when I ride other bikes with flat bars).

This is my first bike with dropped bars (but I have been riding a lot on flat bar bikes before).

There are a million questions like. Are the frame too big? Or are there any other signs? What am I doing wrong? And how do I know :)

The frame is 60cm and I'm 187cm.

Thanks in advance and have a fantastic weekend!

A few thoughts/suggestions:

Try wearing cycling gloves with some gel padding (perhaps you normally do but just were not
for the photo)
Check that your saddle is level - I find that if the saddle tilts down towards the front, then you end  up sort of sliding forward and to stop that, you put more weight on your hands.
Older style brakes are not well shaped for riding "on the hoods" as you demonstrate in the photo.  If you look at modern Shimano, SRAM or Campag brakes (especially the high-end ones) you'll see that they present a wide and flat surface to rest your hands on when in that position.  Older style brakes have a round (cross section) and often U shaped (long section) brake hood.  I have that on my commuter and I agree it means for sore hands quite quickly if the road surface is rough.
Good core strength will help. Can you ride with your hands off the bars, but right next to them?  I.e. Still bent forward, but without being able to rest your hands on the bars?  Actually that's probably too tough a test, and most cyclists who aren't racers can't do it.  But you get the idea: if you can support your weight with your core/back muscles, then you wont get such sore hands.
Compare the drop from seat to bars between your flat-bar bike and the Peugeot.  If the drop is greater on the Peugeot (i.e. the  bars are further below the seat than they are on the other bike(s)) then it may just take some time to get used to it.

Good luck - that's  a great looking bike!


Would you ride with this tire with cuts in the sidewall? I have a next to unused GP5000 road tire, 25mm, which unfortunately has three cuts in the sidewall. I would like to ask, if it these constitutes a safety problem - or if they rather are to be looked upon like regular cuts in the tread.
What is the verdict: dead or not dead?
Thanks,
Morten

I would not ride that tyre.  Pretty sure I can see tube in the second photo, and that's asking for a sudden blowout.

You might choose to put a boot/patch on the inside of the tyre, and use this as an indoor trainer tyre only.   Might be okay on rollers, would make a great front-wheel tyre for a direct-drive trainer (ie, the wheel that doesn't turn at all.)

I certainly would not ride on the road with that ever.

It is dead, buy a new tyre.


Are there any generic hose extensions for frame pumps? I see two kinds of portable frame pumps to carry with me on my riding:

Pmps that have a flexible hose that is either integral or pulled out and/or screwed on (e.g. Topeak Road Morph, or Lezyne).  The nozzle is at the end of the hose.
Pumps that have a nozzle that is right-angle to the pump tube, directly part of the pump itself.

The former are generally quite expensive, and the latter ones don't provide good leverage and are prone to bending the valve tip or coming off the valve while pumping, etc.

It seems so obvious to me that there should be a simple hose of, say 8 inches long, that would have a nozzle on one end to attach to the bike tube and the other end a fake Schrader or Presta valve head that the bike pump's nozzle would attach to.

However, I have not seen them online or in stores.

This product, if it exists, would be able to provide a lot of the convenience of those fancier pumps at a fraction of the cost, not to mention it would be a generic way to upgrade existing frame pumps.  Of course, the extension should be able to handle the air pressure used for bike tires.

Can anyone tell me if they do exist and, if so, where I could get one, or what they are called?

Actually, yes, they do exist and are quite cheap.

The old stype frame pump, the very old style was just a stick with a straight shape. At the business end there was a threaded hole in wich you fitted the little hose. It was a arround 6 inches (15 cm) long, and had the propper head for the valve in one end, and in the other ussually had the same thread as the Dunlop Valve.

Here is the only picture I could find:

These pumps had a receptacle in the handle end, where the hose could be stored. There was a spring inside the telecopic handle, such as to dampen the hit at the end of the stroke, this also alowed you to "compress" the pump a little. The bike frame had a couple of "spikes" pointing at each other alongside some tube of the frame. So to store it you slide the hose inside the handle and inserted the pump between the spikes mentioned before, the pressure from the spring kept the pump in place. That is what you see in the picture, the longest, most shiny tube that is not being held, ia a pump stored in the green bike frame.

Those pump hoses are still available, and they look like this:

There are hoses threaded for Presta (Or Dunlop, it is the same threading) or Schrader. The end that attaches to the pump usually has dunlop/presta threading, so, if this end is long enough can easilly be used as an extenssion for a modern stick pump.

By the way, I managed to get the example picture by typing int the search term "bike pump hose" on eBay. There will be many different options, most are generic replacements for various types of pumps, but these small hoses usually are sold as "adaptors" so the word "adaptor" may be somewhere in the product name too. Use the reference picture to locate the type of hose you need.

If this option is not accesible for you at a reasonable cost, all the DIY aproaches are valid, but the easiest would involve a replacement hose for(from) a cheap pump. A very easy trick for the hose to pump fitting would be to source a good valve stem from an otherwise unusable inner tube. Use the one you like the most (Schrader or presta).


Make bike suspension softer I got a mountain bike with suspension. I'm a pretty light rider so when I actually got on the bike there was no sag what so ever. I believe that it's a spring suspension and it comes with preload.

Is there anything I can do to make the suspension softer since I plan to go head out on some trails. I have already consulted my bike's manual which didn't specify anything and simply stated that I should look up my suspension manufacturers manual. Thing is the suspension is made by the same company and I can't find it anywhere online. Does anyone have any advice? Thanks in advance.

Given the limited info in your question, this answer has great limitations as well.
Preload adjustment is simply a mechanism that adjusts pressure on the spring coils. Increasing preload puts pressure on the spring, slightly reduces the distance between the coils, and results in a firmer/stiffer suspension.  The spring, under increased tension, requires more initial force to respond.  Increasing preload, reduces the amount of sag.

Much of the opposite happens when preload is reduced. The mechanical mechanism that puts pressure on the spring is physically raised away from the spring (everything is still in physical contact), the spring's coils relax a bit, and the suspension becomes more plush: less force is required to move the suspension.  Sag increases.

You state a desire to soften the suspension and reducing preload will accomplish this to some degree.  Try reducing the preload--probably all the way in your case as a light rider.  However, as alluded to in the comments, a lighter (or heavier) than average rider may need a different spring (less stiff in your case being a lighter rider).  In other words, you'll replace the current spring with a different one.   What I think in your case is that since you couldn't find any info online and the spring suspension fork carries the same branding as the bike, it's likely to be cheaply made, difficult to find parts--especially one offering choices of springs of various weights---and essentially not worth further time and cost to change out.


Do I need to replace hydraulic fluid in my brakes? I've had my bike (GT Avalanche 1) for maybe four or five years now.  I've changed the pads once, removed and cleaned all parts on the bike a few times now, but I've never touched the brake fluid.  Does this need to be changed, and if so, why and how?

I couldn't honestly say whether performance has deteriorated over time - they still stop the bike and I don't notice any fade - I'm just curious.

Brakes are Tektro Auriga Comp.

Mineral oil based Hydraulic fluid will build up water condensation in the hoses over time. How much time depends on a lot of factors, like humidity, temperature, bike storage conditions, and similar things.

After 5 years, I would expect that the level of contamination would be high enough to be noticeable, and that the fluid should be replaced. The specific instructions for that brake are found here.


Cannondale SAVE frame technology in entry price I'm wondering if the so called "SAVE" technology from Cannondale makes any difference in the enry-mid price such as Cannondale Trail 4? (they publicize as a micro-suspension technology). In concrete comparing with similar price-range bikes from other manufacturers such as Giant.

Thanks!

All frames flex to some extent due to impacts or road shocks or vibrations. Some frames are better at absorbing this than others. All frame designers engineer their frames to attenuate these imperfections in riding conditions appropriately (for control/comfort reasons) by varying the size/shape of tubes and their compositions

SAVE is Cannondale's marketing term for this engineering. It isn't really honest to call it a "micro-suspension" anymore than any other rigid bike -- its just the frame engineer doing their job.

In a complete bike, you also have to take into account the rest of the bike beyond the frame like the saddle, handlebars, fork, tires, etc. in order to determine how comfortable/controllable the bike is. This is what you should assess the bike on, not some random marketing term.

You should go for a test ride before deciding on a bike. You may find that a bike without some marketing term like SAVE is more comfortable or better value to you than one with that. Or, you may like a bike with it. It would not be advisable to base the decision on buying a bike based on whether or not it was marked SAVE (or equivalent from other manufacturers).


Techniques for patching a tube I asked this question and got very good answers, but now I have a related question.

Do you have any special techniques for patching a tube outside of the generic instructions that are supplied with patch kits, if so feel free to post them, this can include how to locate the leak, buff and clean the area, how to mark the position as to center the patch, etc.

We can assume this is patching done at home and not on while we are on a ride, but you can post techniques for that also, but please make a note about a repair while on a ride.

Comments on types and brands of patches welcomed if they are not already covered in my original question linked above.

Let the Patching advice begin!

Generally you should use a patch kit similar to this  , which consists of patches with rounded corners & feathered edges, a small tube of glue, and a bit of coarse sandpaper.

Usually you can locate the leak by over-inflating the tube (to about twice normal diameter) and then either moving your hand along it or moving it around near your face (your face skin is quite sensitive to air movement) to feel the leak.  Sometimes it helps to move it around near your ear to hear the leak.  As a last resort, fill a basin with water and use that to detect the bubbles.

Discard any tube with a leak within two inches of the stem, or with a leak within an inch or two of an existing patch.  And of course discard any tube with a slit or blowout (except in extreme emergency).

Marking is tricky.  Often the leak is near enough to the center of the tread area that you can simply center on the tread area and only need to mark the position around the circumference.  Other times the leak is more on the sidewall, and you need to mark both X and Y (so to speak) positions.  (Or you can wing it and try to remember where the leak is.)

But remember that you need to abrade the area of the patch (plus at least a half inch beyond its margins) and then spread glue on this area.  This will obliterate any nearby marks, so you need to mark farther away than that.  It's often best to mark on both sides, so you can conceptually draw a line between the marks.

Chalk, a soft pencil, or a fine-tipped felt pen can be used for marking.  (Be sure to test marking first and be sure you can see the mark.)  Avoid using a grease pen, since the grease may get onto the patch area.

Abrade the area of the patch.  If the patch will fall on top of the mold sprue (seam) on the centerline of the tube, you need to abrade that pretty well -- not necessarily enough to remove the "seam", but enough to make it lay flat.

Spread on the glue, going about 1/2" beyond the patch margins.  You don't need a lot, but enough to make the whole area shiny and smooth.  (Note, you WILL get glue on your fingers, especially since the finger is the best way to spread the glue.  Be prepared with some sort of towel to wipe your hands, and don't do any of this on your wife's new hardwood diningroom table, nor should you wipe your hands on the upholstery of the new couch.)

Allow the glue to dry.  Here I may diverge from "conventional wisdom" and the instructions in the patch kit, since I like the glue to be not quite totally dry before applying the patch.  Others like it thoroughly dry, but I find I get better adhesion my way.

Apply the patch.  It comes with a clear plastic top cover and a foil backing.  The trick is to remove the foil without removing the clear plastic, so that you can use the plastic to cover some of the glue while pressing.  After the patch is in place, press it thoroughly, by, eg, rubbing your fingernail back and forth across it.  (The smooth, rounded end of a plastic tire "iron" is useful for this function.)  It's important to do this pressing well, crossing the patch first one direction, then another, applying considerable pressure.

If the patch is on the sidewall where you will fold it while folding up the tube for stowage, allow the patch to "set" for at least another 15 minutes, preferably a couple of hours.  And, before folding for stowage, place a bit of tissue over the glued area (even if the clear plastic is still covering it) since the glue, over time, will want to stick to parts of the tube it touches when folded.  (Another option is to thoroughly dust the area with talc.)  You need the same consideration when installing the tube back in the tire, to prevent the patch from sticking to the inside of the tire.  (In a pinch, when you need to put the tube back in a tire and ride immediately, roadside dust is a good stand-in for talc.)


Are there any studies on fat burning in performance cyclists? I know if you're dawdling along you can eat pretty much anything to keep you going, but if you're putting in effort you need to take on carbs/sugars, right?

Anecdotally from a pro coach who said it varied by rider, as in one of his riders could last for hours on water and a banana, whereas another needed four gels an hour; lots of other anecdotes from amateur riders who can do 80 miles on an espresso etc. But is this non-reliance on taking on carbs in-built/genetic or can it be trained into everybody?

Look at the work of Jeff Volek https://scholar.google.com/scholar?hl=en&as_sdt=0%2C5&q=Jeff+Volek&btnG=
Rethinking fat as a fuel for endurance exercise  is one of his many papers, also Metabolic characteristics of keto-adapted ultra-endurance runners
He has also writen a book The Art and Science of Low Carbohydrate Performance
Low-carbohydrate diets for athletes: what evidence? Is likely to be cited by most recent papers.
These days most of his work is in Type2 diabetes, hence I dont' think he has published much on sport since his book.  Some of his sport research was done with static bikes using
professional long distance cycleists.
Ignore any research that had people on a low carb high fat diet for less then a few weeks before measuring performance as it is a common error other researchers make.


TdF - Mountain stages without a front derailleur? An article on VeloNews about EPO use featured the following photo of Lance Armstrong from Stage 8 of the 2003 Tour de France:

I noticed that Lance does not have a front derailleur. His left shifter has been replaced with a simple brake lever and it appears the front derailleur cable is missing. Contrast this to his teammate's bike (4 cables, both shifters present).

On a flat or medium mountain stage, this setup could make sense as a way to potentially simplify the drivetrain. However, in 2003, Stage 8 finished at the summit of Alpe d'Huez.

It's true that Lance raced using a number of banned substances and pro cyclists are capable of high power outputs. However, given that most (if not all) of his competitors on that day looked to have front derailleurs and that his bike was presumably at the UCI weight limit (set at current levels in 2000) without dropping the front derailleur this seems like a brash decision.

Was this a "Lance thing" or did other pro cyclists do this in the mountains? Are there examples of other pro cyclists going without a front derailleur, post 2000?

Looking at related discussions on reddit it seems he was using a "old style" down tube shifter instead of one on the brake lever.

In the photo, you can see the shifter close to his left knee.

There are other photos showing the same set-ups.


Stack measurement help I'm trying to determine where I fit on the Cannondale Slate geometry because it doesn't seem they use top-tube actual or seat tube, but rather they're using the Stack? I see a great sale on a 56cm bike but that is classified as a Medium and I'm generally a large. I'm 5'11" with around a 33in inseam. Long arms. I believe my other road bike is a 56cm and I'm going to assume it was measured correctly for me. This is sort of an "all road" bike that will be taken on mild single-track, if that changes my measurement decision. What I don't understand is, it appears they're using stack as the bike measurement?

Is a 56cm too small for me? It appears the top tube and seat tube are tiny and has me really confused. I'll also mention I'd prefer not to ride with an overly aggressive seating position.

** edit - These are 650b wheels.

Stack and reach are a 'system' of alternative bike frame measurements always used together. They are supposed to be meaningful absolute values, unlike seat tube length (or 'effective' seat tune length, where top tubes are not horizontal).

They are based on two datum points: the bottom bracket axle axis and the top of the head tube. Stack is the vertical distance between those two, reach is the horizontal distance.

If you have a meter long ruler (or a tape measure and something long and straight) and a level you can measure the stack and reach of your existing bike and make a comparison to the Slate geometry.


Best grease for drum brake? I have a city bike and it started doing some weird noises when brake.

I talked to my local bike shop and they said I should use some specific grease.

Unfortunately in the place where I am currently these brakes are not common at all and I will have to buy it in the Internet. I find several types though and  I am not sure what I should use.

https://www.amazon.de/Hanseline-Bremsmantelfett-Tube-45g/dp/B00O7YCRB0/ref=cts_sp_1_vtp?pf_rd_m=A3JWKAKR8XB7XF&pf_rd_p=1212178327&pf_rd_r=H51QEQ0XKJQCKF4P9SHV&pd_rd_wg=0FzNk&pf_rd_s=desktop-detail-softlines&pf_rd_t=40701&pd_rd_i=B00O7YCRB0&pd_rd_w=5Yy6j&pf_rd_i=desktop-detail-softlines&pd_rd_r=H51QEQ0XKJQCKF4P9SHV&_encoding=UTF8
http://www.ebay.com/itm/Shimano-Roller-Brake-Grease-Fett-fur-Fahrrad-Rollenbremse-100g-Tube-149-50-KG-/400940846506?hash=item5d59efcdaa:g:q8MAAOSwDNdVg7se#shpCntId
http://practicalcycles.com/products/233125--shimano-roller-brake-grease-100g-tube.aspx

Which type of grease should I use for drum brakes?

Are you sure you have a drum brake? A "drum brake" is external to the rear hub and would normally be actuated by a hand-lever (rather than pedaling backwards).

Drum brakes (hand actuated types) themselves don't need grease. If there's contaminants on the drum or shoe, you should just get some "drum brake cleaner" from your auto supply shop. However, more than likely the 'noise' you're experience may be from the wear indicator on your drum brake, indicating you need a new brake shoe. Given that you don't know the manufacturer of your brake, this replacement may be hard to obtain but a new drum brake itself is cheap.

I wouldn't use any 'grease' on a hand-actuated drum brake unless I saw something from the manufacturer. Instead, for noise I'd first try drum brake cleaner from the auto-shop -- and if that doesn't work, maybe use some sandpaper on the drum shoes to deglaze them and take off any leading edges.

Related: When do I know the drum brake is at the end of life and needs replacement?

Coaster brakes on the other hand are actuated by pedaling backwards.  You'll note that the mechanism is internal to the hub.  Some use a variant of a drum and shoe; some use roller clutches - but even the ones that use drums aren't called "drum brakes" by most folks as that refers to the external drum-brake design above. In either case, Sheldon Brown notes:

  Single-speed coaster brakes are intended to be pretty much packed with grease. There is no part of a coaster brake that can be harmed by grease, so be generous in applying it. You should use a grease with tolerance for high temperatures, such as automotive brake grease, but even so, coaster brakes used in mountainous terrain can "cook" any common grease.

  An internal-gear hub with a coaster brake may need more than one type
  of lubricant. Follow manufacturer's recommendations.


Bike sizing question - are these two sizes actually that different? Could use some advice on bike sizing. I'm in the market for a new commuter and after a lot of research I ended up picking this one:
https://www.bergamont.com/gb/en/product/bergamont-vitess-n8-belt-gent#geometry

Unfortunately it's online only so couldn't try it and returns cost £35. I'm 6'0" (183cm) with 33" inseam (84cm). I ordered the large (56) frame but when I hopped on, the top bar was too high and couldn't rest comfortably when standing over it without strong pressure down there.

I'm thinking of ordering the smaller one (52) but wanted to check with you if it's not too small (and avoid another £35 return). Comparing the two sizes - there doesn't seem to be much difference apart from the shorter stack/standover! The seat and head tube are slightly shorter (shorter stack) but the reach is the same. Does that mean that the smaller bike will fit just as well or am I missing something?

Here's a comparison of the two frame sizes (you can see the comparison if you click 'Shadow bike'):
https://www.bikegeocalc.com/#9Bergamonta0b4c789.58314d280e624.25905f788.81524g993.29239h427.82039i340j340k1446.65227l926m1194.58314n765.75095o1251.33031p1005.28465q1272.29156r1404.18714s1006.29693t31.8u40v6w7.75408x10y280z40A0B150C25D458.77624E42F172.5G30H30Z6Berg+Ma0b4c791.02661d280e642.17724f752.08989g995.28771h435.49726i340j340k1443.36749l907m1198.02661n765.60378o1248.09764p986.28465q1275.73503r1391.63503s986.28465t31.8u40v6w7.75408x10y280z40A0B150C25D458.62011E42F172.5G30H30Z

Also full geometry is on the bike website: https://www.bergamont.com/gb/en/product/bergamont-vitess-n8-belt-gent#geometry

Thanks!

You'll get 40mm more stand-over clearance with the 52 over the 56.

As the reach is about the same on both sizes you will not be cramped by the frame, but I suspect the 52 may come with a shorter stem. You may need to buy a longer stem with a little more rise to get the effective (to the handlebar) stack and reach that you need.


How does pedaling power transfer to the bearings in Hollowtech II bottom bracket? I just installed a Shimano Hollowtech II crank and bottom bracket on my bike, and I'm wondering how they work together.

My understanding is that the bearings are located in little cups that screw into the outside of the bottom bracket shell. They are sealed but can spin freely. To install the crankset, first you insert the pedal spindle (with drive-side crankarm already attached) through the bottom bracket shell. Then you attach the other-side crankarm to the pedal spindle via a splined interface and then tighten its two bolts. That much makes sense.

But how does crankarm-spindle-othercrankarm assembly interact with the bearings? In particular, when you apply power to the crankarm (via pedaling), how does that power get transferred to the bearings? The outside of the bearing housing is flat (see first photo below) and I can't see how the inside of the crankarm would interlock with the outside of the bearing housing. The inside of the bottom bracket tube is smooth too, and recommended to be greased up. It seems like the only thing connecting the crankarm to the bearing housing is friction, and that seems like it would slip and be generally unreliable. The only thing determining how tightly the crankarm is set against the bearing housing is how much you tighten the other-side crankarm with the "bearing preload cap" (see second photo below) but the bearing preload cap is plastic, kind of flimsy, and explicitly recommended to be not very tight.

Can anyone explain how this all works together?

You seem to be assuming that "power has to be transferred to the bearings". That is not the case. There is no "interlock". All that needs to happen is that the crank spindle can spin with low friction.

As you pointed out, the inside of the bearings is smooth and so is the spindle. I guess it's possible that they slip relative to each other, but so what -- the spindle/crank still rotates, the chainring rotates, and power is transferred from the pedals to the crank arms to the chainring to the chain to the rear wheel.

In practice, the friction between the spindle and the inside of the bearing is probably greater than the friction between the inside of the bearing and the outside of the bearing, and therefore the bearing spins.  I assume this is the case because the bearing is designed to have low friction, while the spindle inside the bearing is basically like a shaft inside a bushing (a cylindrical hole), which has more friction than a bearing; otherwise we would not use bearings.


Extraterrestrial thing found in my suspension fork! I have recently disassembled my suspension fork and found an extraterrestrial piece of rubber in the coil spring. After some highly accurate measuring it was safe to say that this rubber piece is actually preventing the spring to compress properly. I have removed the thing and the measured travel of my suspension fork doubled from 45mm to ~90mm. I didn't yet have the opportunity to test how it works out on the trails, however.

Do you know what this thing and it's purpose is? If it actually has a purpose, would it be a dumb idea to cut it in half so that it doesn't reduce travel?

It's an elastomer damper, see figure 6 on the image below. Without a damper, the fork would bob uncontrollably like a pogo stick, which is not good at all when riding a bike. Elastomer dampers are a sign of low-end forks, while more expensive forks use oil damping or other forms of damping. You can replace the stock piece of elastomer with less rigid or shorter one to adjust the fork feel.


How do I figure out which size chain my fixed gear bike has My fixed gear bike is going to want a new chain soon, how do I figure out which width I should use?

There two sizes of chains that can be used on a fixed wheel bicycle 1/8" and 3/32".  It all depends on the width of the teeth on the cog and the chain ring.  The most common one is 1/8" as that is what is used on the track and BMX.  On bikes that have been converted from gears to fix are more likely to be 3/32".  My Son's bike has a 3/32" cog, chain ring and chain.


Can no longer shift to lowest gear I recently worked on my derailleur a bit to fix some issues in high gears, however, now I can no longer shift down to my lowest in the cassette when in either crankset.
I have tried the L screw at about any setting, including turning it so far it came completely out, but am still unable to downshift to the largest cog.
I also turned the barrel adjuster quite a bit, with no noticeable difference that I could detect. (Is it possible I need to do many, many turns to get it where it needs to be? It seems unlikely considering I didn't have to make massive changes before to get the other cogs set, but I admit I'm a novice.)
I'm thinking either the spring itself is bad or maybe I need to tweak the B-screw, but I'm afraid of undoing my work that got the higher gears working and going back to square one, or worse, with my shifting. Any help is much appreciated. Thanks in advance!

This sounds like a situation where you should have a professional bike mechanic look at the problem.  If you have attempted to resolve the problem by adjusting both the correct limit screw (you did make sure you were adjusting the correct limit screw, right?) and the indexing via the barrel adjuster, then something else is wrong.  One possibility is that your derailleur hanger is bent, although without seeing it I could not say that is the problem for sure.  Whatever the issue is, if you can't find it yourself, you'd be best served by pulling in some additional help rather than floundering and potentially throwing everything else out of whack.


Can I replace 1 inch threaded fork by a 1 inch threadless one? I have a road cycle with a 1 inch threaded fork. I wish to replace the fork in order to allow larger tires on this bike, but will have to replace the fork.
I find in some shops 1 inch threadless forks. Is it possible to adapte this kind of fork (I guess I will have to change the fork bearings, and stem, too).

It is possible. You just have to remove the old bearings and get a new complete headset for the frame. You then treat it as you would any threadless system.
Note, it is possible to do without replacing the current headset, but it requires you to know exactly what top race and seals you would need. Sealing is specially hard and you will likely end up with a gap and the elements will destroy your headset much more quickly. I would save some hassle and just replace the whole thing outright.
It is also possible to take your threadless fork into a bike shop and cut threads into it, this will likely cost you more in labour than replacing the headset. You also haven't mentioned the material of the work, and this process will depend on that too.
Also remember that the fork steerer lengths are different for threaded and threadless steeres, so make sure the new fork will be long enough.


Is it worth switching from regular "rim brakes" to the new disk brakes? I have an old Haro mountain bike I love. One feature request I have for a new bike is disk brakes. Is it possible to install disk brakes on an old bike? Is it worth it?

It isn't wise to install disc brakes on a frame and fork that weren't designed to withstand the unique forces that disc brakes generate,  and you'll just damage your bike in the process.

If your Haro does have disc brake mount tabs,  then you can install them but likely only with smaller disc rotors.  Remember that you'll have to get new wheels too,  which increases your total cost.

Disc brakes are great for many riders,  but then again so are rim brakes.  Do you really need to switch?


Is "Greased Lightning" safe to use for bicycle cleaning? I am specifically interested in cleaning my chain and drive train. Will it be too corrosive and degrade my 10 speed chain?

A neighbor mentioned he uses Greased Lightning, but I could not find anything on the product website about being safe to use on bicycles (but most everything else), or on bicycle review sites of people using this on their bicycles, many people using on car engines though.

Note: I have used Simple Green (still do) for most my cleaning, and always rinse it off but have been cautious about using it and looking for alternatives, ever since a friend had chain degrade and break after using Simple Green. Lennard Zinn Q&A article about Simple Green eating chains.

In the kitchen section of their web site GreasedLightning says to avoid painted or aluminum surfaces. In my case that is 90% of my bike


Looking for ideas on how to track bike wheel rotations or distance traveled I want to build a hack where when my stationary bike hits 0.1 miles, it sends an information to a webserver which would trigger a web API call.

I understand how the webserver and API call would work. I wanted some ideas on how the said hardware(mcirocontroller or other) would function on the bike itself.

Two main technologies picking bicycle speed are magnetic sensors and pickups counting wheel revolutions and ANT+/Bluetooth sensors with accelerometers  counting wheel revolutions.

Magnetic sensor into a micro controller would be trivial and is not really a bicycle question. ANT+ sensors follow a standardized API so you could look for a micro that support ANT+ and look at the ANT+ API for bicycle sensors.

Not sure how the accelerometers go on stationary bikes as they auto calibrate distance/revolutions, and a stationary bike has 0 distance.

I will ignore GPS...


How to keep my bike safe around campus? I am a new student in the US. I noticed that a lot of bikes were left with only a tire locked on a post. Therefore, I usually locked my bike on the water pipe outside my apartment. I put a U-lock between the water pipe and my bike frame. However, after I left my apartment for a week, it was gone!

Now I have got a new bike, which is an impressive red Giant. I was really worried that it will be stolen again. Can anyone help me by telling me what else I can do to keep my bike safe in that terrible area. Thanks a lot.

This series should prove informative (I have linked the first of three):
Hal will show you!


How to fix numb hands on new gravel bike despite professional fitting and shorter stem? I just bought a new Salsa gravel bike with carbon frame. Despite a professional fitting and shorter stem my hands get numb after only a mile. I wear padded gloves when riding. I have ridden a Trek road bike for over 15 years and never have had this issue. Any ideas on how to fix this problem? I'm ready to return the bike.

Look at the position of your shifters. It is often overlooked, people talk about positioning the handlebar by lowering/raising the stem, shortening the stem, but you can also move the shifters on the handlebar. Make your wrists comfortably straight. Many people (and shops) place their shifters too forward/low. Try to bring them back/up a little.


Wheel with Centerlock hub for disc brakes and rim for caliper brakes Does it make sense to build a wheel with a hub with Centerlock for disc brakes and a rim for caliper brakes?

My idea is to use the front wheel with a dynamo on two bikes, if I decide that I need a light on my more sportive bike, or to use the wheels for a future bike with disc brakes.

E.g. Shimano Deore LX DH-T675 + Mavic A 319

I've used such wheels for some time on my hardtail. First with V-brakes back and front, then switched to disk brakes as the frame allowed both types of brakes. I cannot say that I have experienced any issues with such wheelset.

My centerlocks hubs even came with plastic covers on disk mounting surfaces so that they would not become dirty when no disks are present.


11t-40t/42t cassette on 3x9 system I need your help about gear ratio.
I am currently riding 3x9 drivetrain, Deore m592 rear (SGS-Shadow), Deore XT m770 front.
My gear ratio is:
11t-32t (rear) and
22t-34t-44t (front).
My local hills and trails consist of hard uphill and some small downhill tracks. The hard uphills are the reason why i want to make a change in my cassette ratio.
I am planning to upgrade to a bigger, 11t-40/42t cassette, but I'm confused if this is possible with a 3x system or not.
I've read that the max cog (rear) for some derailleurs (including my SGS Deore) is 36t, but a lot of people say that 11t-40/42 or even 46t is possible. Are these cassettes too large for a 3x9 drivetrain? Do I need to convert to a 2x in front as well?
Will a hanger extender + the b-link somehow make it possible to get the cassette size i want?
Any help would be appreciated.
Thanks in advance :)

It's not clear why you would want to use an 11-42 cassette in a 3x drivetrain. 11-42 cassettes are typically used with 1x or 2x systems. With a 22 tooth chainring and 34 tooth sprocket you already have a pretty low gear ratio (0.65) - lower than a typical 1x drivetrain with a 30 tooth chainring and 11-42 cassette (0.71), and only a little higher than a 2x 36 tooth small chainring and 11-42 cassette (0.62).
Just to give you a definitive answer on compatibility: the two derailleur specs you need to know about are the max cassette sprocket size and the total capacity. Max sprocket sizes is obvious, total capacity is the ability of the derailleur to take up slack chain and needs to be greater than or equal to (difference in largest/smallest sprocket size) + (difference in largest/smallest chainring size). Your current setup requires capacity of (34-11)+(44-22) = 45.
You can find Shimano specs here: https://productinfo.shimano.com/#/, in the archive PDF spec sheets. The M592 SGS has max sprocket of 36, total capacity of 45 - which obviously precludes a larger range cassette.
If you used a Alivio 2x9 crank with 36-22 rings and a 11-42 cassette the capacity requirement would be (42-11)+(36-22) = 45, but your derailleur still can't handle a max cassette sprocket over 36 teeth. (Although, I've heard of people successfully using a derailleur hanger extension to accommodate a large range cassette.)


Shifting is crunchy in Shimano CB-E110 Looking for advice for my GFs Pelago Brooklyn, which has a coaster brake Shimano CB-E110 hub. When shifting gears, the chain hops and crunches. The chain also looks a bit saggy. I only have experience with maintaining single speed and fixed bikes, so I was wondering what can I do for it?

Pelago web site says this bike comes singe speed or with a 3 or 9 internally geared hub, CB-E110 is a single speed coaster brake hub, so perhaps you actually have one of the IGH options.

If the chain is skipping over the rear sprocket the the chain tension needs adjusting, just as on a single speed.


Polite/Proper Way To Notify Pedestrians and Bicycles A question on a bell had a lot of comments on how to notify pedestrians.

How do you notify a pedestrian you need to pass?

How do you notify a bicycle you need to pass?

I imagine this will be region dependent so please state your region.

This is getting a bit of response and it clearly varies by region.  I will give it a couple more hours and just award the answer to the most votes.

From Southern California, when approaching slower traffic from behind on bike lanes and paths: "On your left" meaning that you are passing them on their left-hand side. Only left. People hear the "On" portion of the call and they start moving to their right.

I can't ever recall hearing "On your right". Good thing, too. Would be a mess.


Pendulum motion when riding out of the saddle When riding out of the saddle, you will often have to rock the bike laterally for stability.
My question is: how do most people synchronise this pendulum motion with their pedal stroke?
In which direction and when should the lean be in relation to the moment you push down on one pedal?
Personally, on each stroke I lean the bike on the side of the foot pushing down, but this GCN video seems to demonstrate the opposite: leaning the bike on the side of the foot not pushing down.
EDIT:
More specifically, what I do is I am leaning the away from the 'push down' side just before I push down. At the instant I do push down, the bike inevitably leans towards the push down side, reaching maximum lean when the foot pushing down reaches the bottom of the stroke (which is when the other foot starts the next stroke).

You lean the bike in the direction of the leg pushing down? That's quite unusual.
When you sprint, you're effectively throwing all your weight on one leg, then the other. If you were to just stand on one pedal with the bike vertical, you'd flip over the bike from the one-sided force. To counteract this asymmetry, most people lean the bike opposite to the downwards leg.
This also gives you an effectively longer crank for more leverage, as the leaned-up side will have the pedal higher than normal max, while the leaned-down side will have the pedal bottoming out at lower than normal minimum height.


E-bike speed limit in Ontario, Canada In Ontario, Canada, may I pedal my e-bike up to the road's posted speed limit without motor assistance?

Like if my bike does 31 mph but the speed limit is higher, can I travel to that speed without motor assistance?

I think your question is "can I go as fast as the speed limit of the road if I'm not using the electric motor?"  The answer, in Ontario (thank you Google) appears to be yes.
The "Ministry of Transportation" of Ontario has a page on electric bikes as well as a FAQ, both of which say that the bike can't exceed 32km/h.

No modifications to the motor to allow it to exceed a power output greater than 500W and a speed greater than 32 km/h.

But this seems to apply specifically to operating the bike on motor power, though it's not clear from the quote.
Digging a bit further, the governing law (the "Highway Traffic Act") defines a "power-assisted bicycle" as:

“power-assisted bicycle” means a bicycle that,
(a) is a power-assisted bicycle as defined in subsection 2 (1) of the Motor Vehicle Safety Regulations made under the Motor Vehicle Safety Act (Canada),
(b) bears a label affixed by the manufacturer in compliance with the definition referred to in clause (a),
(c) is fitted at all times with pedals that are operable to propel the bicycle, and
(d) is capable at all times of being propelled on level ground solely by using muscular power to operate the pedals;

That appears to defer to a parent law (the "Motor Vehicle Safety Act (Canada)") in the parent jurisdiction.  The relevant portion of the "Motor Vehicle Safety Regulations" states:

power-assisted bicycle means a vehicle that:
(a) has steering handlebars and is equipped with pedals,
(b) is designed to travel on not more than three wheels in contact with the ground,
(c) is capable of being propelled by muscular power,
(d) has one or more electric motors that have, singly or in combination, the following characteristics:
   (i) it has a total continuous power output rating, measured at the shaft of each motor, of 500 W or less,
   (ii) if it is engaged by the use of muscular power, power assistance immediately ceases when the muscular power ceases,
   (iii) if it is engaged by the use of an accelerator controller, power assistance immediately ceases when the brakes are applied, and
   (iv) it is incapable of providing further assistance when the bicycle attains a speed of 32 km/h on level ground,
(e) bears a label that is permanently affixed by the manufacturer and appears in a conspicuous location stating, in both official languages, that the vehicle is a power-assisted bicycle as defined in this subsection, and
(f) has one of the following safety features,
   (i) an enabling mechanism to turn the electric motor on and off that is separate from the accelerator controller and fitted in such a manner that it is operable by the driver, or
   (ii) a mechanism that prevents the motor from being engaged before the bicycle attains a speed of 3 km/h; (bicyclette assistée)

So the actual requirement in governing law is that the motor can no longer provide assistance beyond a speed of 32km/h, not that the electric bicycle can't go faster than that.


Frame manufacturer not covering crack as saying it was crash damage My Ti frame developed a huge crack in the frame a week or so ago. A pain I thought bit it'll be covered by warranty...

The frame builder is now saying that it's crash damage.

I really really doubt it's crash damage.

I have fallen off this bike twice, once I went into the back of a slowing cyclist, the other my front wheel came out from under me and I slid along the ground.
Both of these were nearly 2 years and around 10,000 miles ago.

What can I do? It's my word against theirs.

They said that scratches on the hoods mean that it's been crashed! Those scratches are 2 years old when the bike slid along the ground. Scratches on the frame are from when I leant it against my garage wall and it fell over. They can't use scratches to determine if it's crashed.

Absolutely fuming about this, I hope some of you guys can help.

I live in the UK for your information.

Some pictures:

Despite what others have said, a warranty is a bona fide contract between the company and you. It's used in the selling of the product thus is covered by decent consumer protection law (in the UK anyway). This article from Which suggests a good process to follow.

Keep a record of the contact with the company, try to follow their warranty procedure. If you're sure that the warranty exclusion isn't valid (crash damage), then it'd be worth getting an independent opinion on whether or not the crack was crash damage. A good bike shop should be able to write something up for you. Then show that to the company.

If you end up in a deadlock with them, then contact the financial ombudsman. Another avenue to follow might be section 75 of the Consumer Credit act.
"Don't forget that if you pay for anything with a credit card between the value of £100 and £30,000, your credit card company can be jointly responsible for any faults that develop. You can either claim for a refund using Section 75 of the Consumer Credit Act or, if you are looking to get the product repaired, you can claim for the cost of repairs."


I bent a rim, what kind of new rim should I buy? I bent a rim on a wheel that has a tire that’s 25-622 (700x25E). What kind of new rim should I buy?

What kind of rim is compatible with this tire? I do not know how to size rims.

You say you want to replace the rim, but unless the hub is something special, or you're going to rebuild the wheel yourself, it's probably cheaper to replace the whole wheel.

If you're replacing the rim, apart from approximately matching the rim width (see Sheldon Brown) you also need to match the number of spoke holes if you want to reuse your hub, and it's a good idea to replace the spokes that have been damaged. If you have rim brakes also need to make sure your new rim has a braking surface.

If you're replacing the wheel, you need to match the hub type and size. The type could be quick release (QR), thru axle (of which there are a couple of sizes) or nutted with dropouts (again multiple sizes). The relevant size is the over locknut distance - the width of the hub. You also need to know whether your old wheel used disc or rim brakes, and if did, what type and rotor size.


Information about Olympia bicycles There is a bicycle dealer in my area selling "Olympia" bicycles. I haven't seen any athlete riding those bikes and I was unable to find any reviews on the internet. I know that the company is one of the oldest ones in Italy.
What I want to know is where do the Olympia bicycles stand in comparison with the other top brands like GIANT, Trek, BMC e.t.c.

Olympia bicycles are as good as any, and the company has been doing for about 100 years longer than any you mention.

Having said that Olympia produce good bikes, they have a different brand for pro-level equipment: Scapin, one of which I am privileged to ride.

I gave an Olympia to my brother-in-law, three years ago. He's been riding it 500 km per month ever since without problems.


Does greasing the threads of an inline barrel adjuster cause slippage? I am considering adding a hint of grease to an inline barrel adjuster.

When the barrel adjuster (C) fully gobbles up the metal threads (B), it can be hard to determine whether turning the barrel adjuster actually increases/decreases the tension in the cable (center line). It could be that the cable housing (A and D) are slipping against the metal parts (B and C).

Swifty commented on this issue:

  I have used both grease and oil on barrel adjusters, depending on what
  is at hand. Oil will get it moving but not last as long, grease will
  reduce friction and stick around to protect the threads. No issue
  around the adjuster moving when you don't want it to, it's
  held/compressed together by all of that cable tension anyway.

But I'm worried. If I add a hint of grease between B and C, wouldn't the constant compression between the two threads (B and C) cause the B part to gradually disappear inside the C part, ruining whatever fine tuning you started with?

Another way of asking this question, by way of analogy, is this. Say you have a piano swivel chair. The top spins to adjust the height of the chair. But if you lubricated the joint well enough, someone sitting on the chair and lifting their feet off the ground momentarily will find themselves spinning from the pressure exerted by their own weight on the two helixes that are the threads. The cable housing is likewise under constant compression. Does compression + lubrication cause slippage?

Update

The barrel adjuster in question is made of aluminum, which can only be polished so much. For barrel adjusters made of stainless steel (do these exist?), it's perhaps possible to rely on the sheer polish of the surfaces and never need to grease the contact surfaces, but for aluminum, it appears almost necessary to add a hint of grease.

It is very unlikely that the constant compression on the joint would result in any turning of the barrel adjuster.   Two factors affect this:

firstly the friction between the threads and the friction between the adjuster against the cable sleeve has to be overcome.  The way friction works is that until a minimum threshold force is reached there is no movement.  Multiple tiny jolts do not add up over time, they have no effect at all.
Secondly there is a negative leverage effect when turning the threads.  When tightening a bolt the bolt applies a much greater force on the job than the spanner applies on the bolt.  In this case you are working in reverse, so the compression force on the threads results in a very much weaker turning force on the barrel.*

It is extremely unlikely that the return spring on a brake caliper or gear shifter could provide anything like enough force to overcome the friction and turn the adjuster barrel.

Any turning effect that did happen would probably come from mechanical vibration or something banging or rubbing against the adjuster.

* one way to look at this is that the flats on a bolt with a 5mm head travel 3.14 x 5mm in each turn.  The bolt moves forward maybe 0.5mm.  So the force gets amplified approximately 30 times.  In reverse the pressure on the bolt is weakened by a factor of 30 when it tries to push the flats around.

UPDATE

For anyone interested in how lubrication makes a difference:

There are two types of friction, static friction and dynamic friction.  Static friction states what the resistance to movement will be for two stationary surfaces in contact.  For any two surfaces the sideways force needed to make them move is proportional to the force pressing them together.  Typically for dry metal-metal contact this coefficient of friction is about 1, i.e. a 1 Newton force pressing the surfaces together means a 1 Newton sideways force is required to make them move.

Once the surfaces are moving then the coefficient of friction generally falls to a lower value.  For dry metal-metal surfaces the static and dynamic coefficients are about the same, getting the surface moving does not change things much.

Lubricating surfaces typically lowers the coefficients of friction.  However, the lowering is not equal: for typical metal-metal contact lubricating lowers the static coefficient a bit, it lowers the dynamic coefficient a lot.

So, lubrication does not make the barrel adjuster much easier to turn, but once you have got it turning lubrication does make it easier to keep on turning.

Finally: we need to consider the difference between force and impulse.  If I tap my car with a pencil it applies a high force to the car (listen to the sharp explosive sound it makes).  The car does not move because the duration of the force is transitory, the impulse imparted by the pencil is minimal.  If a tow-truck rolling very slowly gently nudges the fender the car moves along the road.  The force is low (no sound, no damage) but the duration is long and the impulse is considerable.

Imaging a pencil tapping the barrel adjuster.  It may well have enough force to make the adjuster move, but the duration of the force is minimal.  Theoretically it will get the adjuster to move, but in a random direction and for an infinitesimal distance.

On the other hand the return spring, a twisted cable etc might be able to apply a smaller force for a long time in a consistent direction.  It can't get the adjuster to start moving, but if it could then theoretically it might be able to keep it moving one-way for a non-negligible distance.

However, lubricating the adjuster still won't allow the spring/twisted cable to get the adjuster moving because lubrication does not change the static friction much.

Add lubrication and the pencil tap together and they might make a difference.  The pencil tap adds a negligible movement in a random direction.  Even so it is a movement, and the lubrication has lowered the dynamic friction so that might allow some other force (low but in a consistent direction) to keep the adjuster moving for a while in one direction.


DIY solution for carrying kids on a long-john: ideas? I ordered a long-john (namely, a Bullitt Clockwork) and - the official folding seat/composite honeycomb bottom being way too expensive for my budget, I am now in the process of building a passenger seat for my son (1,5 years old).

I wish my seat to:

Be safe
Be cheap to build
Have the possibility to tilt backwards (or anyway having it designed in such a way that when my son falls asleep during longish rides his head won't bounce all over the place).

My first impulse was to build something akin to the box the bakfiets comes with:

But while being cheap to build and relatively safe (the kid is enclosed in a solid structure) there is no support for the neck/head, nor the seat can be reclined.

My second idea was to still build the box but enclose/fix on the bottom of it a forward-facing child seat designed for cars.  Not owing a car, I'm not sure of how that works, but I know as a fact that my friends children routinely sleep in them.

However this solution is relatively expensive/heavy, and in addition I either fix permanently the seat to the box (and then I need to always shelter the bike from rain/snow) or I make it releasable (and then I'll have to carry it around if I don't want to get it stolen / be soaked by rain).

Finally, the last idea I had was to mould a box-cum-integrated-seat in FRP (fibre reinforced plastic, think "fiberglass").  I have some experience with previous projects and the end result is light and durable, but getting it done is a labour-intensive process.

So, my question is: does anybody have an alternate idea on how I could build the seat for my son? Or an off-the-shelf solution that won't cost me an arm and a leg?

Putting child seats designed for car use into or onto cargo bikes is very common. The basic idea is to work out how you can mount it to your bike using something similar to the way the seat you have is mounted in the car so the mounts work properly. Just grabbing one and bolting it to your bike could easily result in it ripping off in a crash.

That said, I've seen a lot of people just drop the seat into the box and vaguely tie them upright. If you're going short distances at low speed, and you don't crash, that works. There's no real benefit in having a proper car seat if you do this, whatever baby container you have will work just as well/badly as long as the baby is somewhat strapped in and it's reasonably robust.

If you have a pram or push chair that you can remove the wheels from making a mount for that on the bike is probably going to be the cheap option.

The next step up is to anchor it properly by using the bracket that holds the box onto the frame and attaching straps to that that attach to the seat where the seat-belts do. Often that just means a piece of timber and some old seat belt straps held on with screws and washers. It's a bit crude but it works.

A different approach is to buy a seat that's designed for a rear rack and mount that in the box somehow. The easy way is the run a length of 2x4" timber the length of the box and bolt a rear rack to that (if the seat has quick-release mounts for the rack) or just bolt the seat to the timber. Then make a frame for that bit of timber that you can attach securely to the box but also remove when you need to. The advantage of that is that you can get a seat that has a headrest for your kid.

But if you're comfortable working with timber, I'd be very inclined to make something that does exactly what you want. Have a look at how standard bikes seats work and build something similar, probably with more padding. I'd be really tempted to make a wooden "cowl" that the seat can lean back into to support the kids head, but when the seat tips more upright doesn't get in the way. And use 100mm thick foam for the lining, rather than trying to suspend a wooden box.

This is based on what I've seen around the place since I don't have kids of my own. I'd say less than 10% of new parents that ride have a special baby-on-bike carrier, they almost all use a car carrier or similar and tie it into the bike.

cargo bike with two kiddie seats


Fork trail vs chainstay length in steering Is fork trail or chainstay length is a bigger determinant in the overall steering of the bike?

Consider an arbitrary frame that I think is steers too slowly.  I'm going to rebuild it because I want a fun project, have some scrap metal, all the parts, and I want to build another similar bike that steers a bit quicker and is more racy.

All other things being equal, mainly the head tube angle, would building another frame with shorter chainstays be a better way to go about it than using a fork with less trail?

I'm interested in the rate of change in the steering of the bike while changing those two factors, and which one affects the steering more, and by how much if it can be measured - i.e. 1mm change in trail could be offset by 2mm change in chainstay length (that's probably wildly inaccurate - I'm hoping to hear from some frame builders).

Because you steer a bicycle with the front wheel (and weight offsets), the steering of a bicycle is almost entirely determined by the geometric parameters of the front wheel and where it is located. The most determining factors are:

Trail
Wheel flop factor
Front wheel radius

Trail and wheel flop factor are determined by steering angle, fork offset and wheel radius.

The chainstay length is irrelevant in this respect, but it does matter for the overall handling of a bicycle. For example it has an influence on how well a mountain bike climbs. For road bikes it has some influence on the weight distribution between both wheels.

There are tandems which handle like a good road bike (except for the turning radius). They essentially have "chainstays" that are almost 1.5 m long.


Triban RC 100 upgrade I hope you're all safe.
I'm looking to upgrade my Triban rc 100.
It includes Shimano Touney groupset and Microshift x7 cassette.
Currently, the groupset that attracts me the most is the Shimano Tiagra 4700 2 or 3x10 and a compatible back wheel.
However, I'm want to ensure that I can mount this groupset on my bike.
Therefore, I would like to know if this groupset would be compatible with my bike frame.
Could someone please help in discovering this, as well as other considerations I have to take into account before upgrading?

Thank you in advance for your time.

It should be quite possible. Even the rear wheel hub might work as is if it really is a cassette (most likely CS-H072 12-28) and not a freewheel. You will also need a new bottom bracket with the new chainset. You may decide whether to keep the brakes or not, it is possible.

Overall it will not be cheap and you will have a cheap frame with a good groupset and potentially cheap wheels. It is up to each individual to decide whther it is worth the investment. Cheaper groupsets, like Sora and Claris are also decent, but have less speeds. Again, up to everyone's individual decision. The no-longer needed components can be sold, but will not be worth that much.

I would suggest to think twice about the 3x cranks. They are not very popular today, because modern modern gearings allow wide range of gears with 2x cranks. The difference between those two chainrings is now most often 16 and that is more than it traditionally used to be. With 10x speeds in the rear the spacing still should be good enough even though modern rear derailleurs allow cassettes with a wider gear range.


What's the best way to fix up my used bike? I bought a used bike on craigslist, for cheap, and while I wasn't expecting it to be great the brakes and changing gears don't work perfectly.

The front brakes are very tight and the back ones are pretty loose... I can stop and everything but just would rather have a better performing system.

The gears change but sometimes don't work that well and I have to move the shifters all around for it to "stick" in a gear. Is there some way to simplify the gear structure? I wouldn't mind a single or fixed gear transition (since I live in NYC) but still want the ability to coast and use my brakes (assuming I can fix those too)

Simple adjustment

It may be that your brakes and gears are simply out of adjustment. The easiest way to confirm this would be to take it to your local bike store (LBS) and ask them for advice. Most stores are pretty friendly and helpful towards keen amateurs.

If they advise that it's just adjustments they can do it themselves, or show you the adjustment screws so you can try it yourself.

More significant work

It may turn out that there is more work required, such as replacing brakes or gears. Also the chain, cassette and chainrings may need replacing.

In this case I'd be very wary of investing too much money into the bike. Buying components individually is a lot more expensive than buying a complete bike. Plus making sure parts will fit can be confusing and unreliable. If there's much wrong with the bike I'd say it'd be cheaper to buy a new bike where you know that all the parts are at least compatible and in good condition.


Looking for a narrow-cage 16T capacity FD I'm putting a 46x30 chainring with a pretty narrow tread on a frame. On the advice of my LBS I got a Sun XCD double FD, but I'm starting to think it's not right for this application. When I have the derailleur on the big ring and far enough out to avoid rubbing, there's razor-thin clearance between the outer plate and the crank arm. And that's just on the stand -- I'm worried that once I'm on it and things are flexing, the crank is going to hit the cage.

I think a narrow-cage derailleur, and maybe one that is designed for smaller chainrings (the Sun is listed at max 56T) will be a better fit. Does anyone have any recommendations?

There will be only very small differences in the widths different FDs (assuming you are talking about the inside to outside dimension). One that is designed to be minimum sized so that it provides a best fit for 46t large chainrings is Shimano's CX-70, intended for cyclo-cross:
http://bike.shimano.com/publish/content/global_cycle/en/us/index/products/cyclocross/cx70/product.-code-FD-CX70-B.-type-.fd_road.html
It does have a 16t capacity. It is also compatible with the bar ends (which don't index the front anyway).
I have purchased one of these to use with a similar chainring setup and 105 dual-STI brifters, but I have not yet installed it.


What happened to hardtails in the past 15 years? So, last time I bought myself a new bike was around 2004 - that was a Trek 4300 hardtail which was a mid-range model and I got it for about $300. I upgraded it with better derailleurs, disc brakes, wheels, better front fork and it had served me faithfully over thousands of miles of road trips for 7 or so years until I'd moved.

When I moved I picked up a used newer gen (2009 or so) Trek 4500 for $300, had done similar upgrades and had been pretty happy with it.

I consider myself a fairly typical MTB rider. I don't compete, I don't focus on a single discipline (like BMX or downhill), I would just leave my home with friends or kids on a sunny weekend day and do anywhere from 20 to 60 miles over mixed terrain - some asphalt, some forest roads, some hills, some trails, occasional downhill segment. I'm happy with the workout I'm getting and I'm happy with 26" wheels with semi-slick tires (slick center, grippy edges) which allow me to enjoy riding fast on paved roads and get a decent grip on muddy/gravel trails.

However, every time I step into a bike shop now, I raise my eyebrows a bit - two things surprise me greatly:

It seems that you can't get a new cross-country bike from a decent brand for less than $2,000 anymore.
All MTBs have single chainring now and 10 or 11 sprocket cassette in the back.

On the account of chainring - I am surprised that people settle for much lower max gear ratios in riding scenarios like mine. I read stuff like this and the authors admit that single chainring means compromising your top speed but make the argument that you shouldn't really bother. I'm not quite buying the argument - I find myself using the 3-10 combination at ~90rpm pedaling cadence every once in a while when I want to ride fast on a paved road.

The prices just surprise me - there are no more $300 MTB hardtails in bike shops (or the ones that are there are kids models or horrible no-name brands or knockoffs). I understand that a lot happened since 2004, but going from $300 to $2,000 still seems a bit steep. E.g. browsing through Trek website, I can see that Procaliber 6 is roughly similar in terms of component quality to what 4300 used to be 15 years ago, but 6x price increase seems a bit unjustified. Also, looking at the single chainring on that one - I just don't see why I would replace my good old 4500 with that.

I'm sure I'm missing something here. What was the generational shift that happened? Are people enjoying mountain biking differently these days? If I embrace the new way, dump my old 4500 in favor of Procaliber, will I experience 6x the fun? What's the deal with single chainring? Is it that much better?

To focus discussion better - let me ask just one question:

Why should I buy a new bike these days (other than the "smell of new leather")?

To paraphrase the question: Why aren't there any quality hard tail mountain bikes for $300?

Wouldn't it be reasonable to expect prices to go up since 2009?
None of the following examples are an endorsement. Only an attempt to point out that there are still less expensive good bikes available.

In an aluminum frame Trek has the Marlin 5 that sells for a little over $500.
It does have 29 inch tires but it does have triple chainrings and a seven speed cassette.

If steel is OK then the Trek 820 is $400.
It has 26 inch wheels and triple chainrings with a seven speed cassette.

Maybe the shop you visited didn't have these bikes on the floor.
Less expensive name brand hard tails with triple chainrings do exist.

Most major brand bicycle companies define a type of bike and a price range they want to compete in. For example "road bikes in the $500 price range" would be a product slot in their lineup. In this case "mountain bikes in the $400 to $500 price range" would be a product slot. Specialized slots their less expensive mountain bikes between $600 and $750. All that to say - Trek isn't the only one with bikes in this slot.

The single chainring bikes you are seeing are the result of the increase in the number of speeds on cassettes and/or a focus on cross country or down hill riding. With as many as 12 speeds on the cassette some people have seen an opportunity to get rid of the front derailleur and simplify the bike for some types of riding.

Edit:
The question shifted while I was writing my answer!
I think this answer is still relevant.


How to mount SRAM snaplock? I am trying to join PC-1 SRAM chain, it has such snaplock:

And the problem is, the distance between holes is slightly less (IMHO) than distance between the pins. Every hole on its own fits any pin, but so far I am unable to put the golden part onto the pins, either one holes fit, or the other -- and I cannot make them both snap at the same time.

I have manual for this chain, but irony, it describes how to use silver power lock (asymmetric), not this one.

So, how to mount it? Should I use tools like pliers?

Put link into chain, hold chain on either side, use thumbs to hold snaplock over link. Gently pull chain using thumbs as fulcrums...this will put pressure on the pins forcing them just a tiny bit inward. Snaplock should slide over. (Think of it kind of like bending but not breaking a pencil...both hands on pencil (chain), thumbs next to each other, gentle pressure.


Chain shortening only one link? Is it possible to shorten or extend a chain only one link as shown in the photo (in red square). Or do I have to shorten at least two links in order for the other end to match?

The reason I'm asking is that with my current setup (front 52/36, rear 32/11) if I remove one link the chain becomes too short to shift to 52 front and 32 rear. If I extend the chain one link and shift to 36 front and 11 rear, the chain rubs on the derailleur.

For 1/8" chains as used on singlespeed bikes (or with hub gears), half links are reasonably common.

They do exist for 3/32" chains (which are sometimes used without derailleurs) but are much less common as single speed 3/32" chains are. They're not needed if you've got a test derailleur as the derailleur provides much more chain length adjustment. A chain tensioner can do this on a singlespeed.

The main reason for using these appears to be on singlespeed conversions, when they lack the horizontal dropouts of a frame built for single speed.


Chain guide/tensioner for 2011 Giant Reign 2 (Press Fit) Can someone recommend a chain guide/guard/tensioner that will be mountable to a 2011 Giant Reign 2 which has Shimano Press Fit and 3-ring crankset? The best I could find is:

Kore Chain Reactor - available at ebay.co.uk
Brand-X Chain Tensioner
Bionicon c.guide 2 - reported as not very durable (breaks)
Bionicon c.guide eco - hopefully more durable

I need something that ships to European Union (Czech Rep.). Thanks in advance!

One possible and modern solution is: none. Go 1x10 or 1x11 with a narrow wide chain ring and a RD with a clutch.


Is there a title that refers to the person who selects the athletes who will join the national team? Is there a title that refers to the person who selects the athletes who will integrate the national team (for instance, in the Olympic Games)? In football(soccer), there is a Selector (Sélectionneur in French) that will create the national team. What is the equivalent in bicycle racing?

The correct title in English speaking nations is Selector. The Selectors use their knowledge of the capabilities and nature of the riders to select those that represent their region or nation. Results are important but if look up any selection criteria you will quickly see behaviour standing out as one of if not the key decider on who gets to represent their country of the elite riders. Selectors work in groups and often are made up of head and team coaches and other national federation members.

Selectors also play a role in identifying talent and bring young riders into the high performance programs offered by the national federations.

There are many hoops to jump through before being selected as a representative. Firstly a rider must be eligible this involves:

being a citizen
holding a racing licence
clean drug tests
attend sanctioned events and training as required

Once eligible selection is then based on a number of factors:

results and performances at national and international events
UCI world cup points
performance in selection trials
ability to work well in a team
would the athlete win an Olympic spot and could they go on to win a medal
technique in team races
behaviour and attitude
sport science results
fit in team composition (mainly in track events)

So in short, selection is based on not only results but a wider analysis of the rider. The Selectors still have a large role in ensuring that the national team is the best group of riders rather than the group of best riders.


Bike keeps suddenly changes gears w/o me shifting I've noticed that there are times that my bike suddenly changes gears, without me touching the shifters. It usually happens when I'm on a hard gear and I suddenly power out of a full stop, it pops into an easier gear and my foot drops from the pedal. What's happening, and how do I prevent it from happening again?

If your chain is dropping on the front ring, it can be:
1. your BB is lose and shaking.
2. your derailleur not properly adjusted.
3. your crank is lose and shaking.
4. your derailleur or crank is bent.


How to fix a sluggish bike? I just bought a used mountain bike, and it seems to be slow.  Pedaling seems like very hard work, and at a normal casual pedaling rate, I can only reach 4-5mph. If I pedal like I'm being chased by a lion I can get up to 10-11mph for a few seconds.

For reference, I can run a 6-minute mile, so I can run faster than that.

I'm thinking it's probably the bike, because the chain looks dirty and the wheels make scraping sounds as it moves.  (I don't know if it's scraping against the brakes or something needs oil, etc.)

How can I fix this?

Since it's a new-to-you secondhand bike, for safety's sake as well as to deal with the sluggishness I recommend you take it to a bike shop for a complete overhaul. I'll bet you'll be astounded at the difference when they're done.


What effect does seat tube angle have? I know that head tube angle affect steering, but does seat tube angle affect maneuvering somehow? As long as I compare a few models, they are between 72 and 74 degrees, and greater the frame smaller seat tube angle. So I guess difference by a few degrees doesn't have considerable effect.

Here're the comparisons.

Specialized geometry
Trek geometry

As for sheer maneuverability, seat tube angle may in some (rather extreme) cases affect wheelbase, which affects stability at variety of speeds. Also seat tube angle will have some minor effect on the position of rider's centre of gravity making it slightly easier to descend with smaller seat tube angle... I guess it would be an unnoticeable difference though.

But main aim of angled seat tube is above all to make pedalling more correct in a biomechanical way, thus more efficient..... and making it possible for a rider to reach the ground while still being on the saddle, say when they're stopping. For the right distribution of stresses within your joints you need an angle adjusted to your body - people with longer thighs will need smaller angle. In general too low angle encourages lower cadence and more forceful pedalling which isn't very good for your joints. What's interesting is that it doesn't work the other way round - it's possible to ride relatively safely with very high angles - it's usually 78-80 degrees for TT bikes. (I meant to put an article titled "Myth of K.O.P.S" for Sheldon Brown website, but the link doesn't seem to work)

Here is the link to Sheldon's Myth of K. O. P. S. (knee over pedal spindle) article.

Seat tube angle can be quite well made up for with fore-aft saddle position, so 2 degrees in difference can be easily neutralised. And the differences in angles between sizes may come from various sources:

it could be forced by the design, for example to avoid some weird top tube length or too short distance from the crank to front wheel.
it may also be a form of adjusting the geometry to body proportions of riders of different sizes.
or it could be done to lower the centre of gravity for a large rider, that for large sizes is pretty high anyway.

Or it could be a mix of the above, we should ask the designers.


Lowest rideable gear ratio What is the lowest rideable gear ratio (chainring/cassette) possible without feeling like having to balance/trackstand? I'm doing some virtual simulations right now and I'm just setting up IRL limits. If it differs on road and mountain tires, I'd like ratios of both.

One issue is that it can be harder to balance a bike while spinning like crazy than while pedalling more sedately. Timing a gap in traffic, for example, I can get below 1km/h, but changing right down is a mistake because when I want to get going again I'm trying to push 100rpm after a couple of strokes.  This is worse if I take the MTB on road, because of its smaller small chainring - it has very limited use.

Another is that gearing too low produces too much torque, which is worse on steel uphills. With your weight on the saddle or over the back wheel, the front wheel will lift, but with your weight forwards the back will slip. I've had this on trails (MTB) and wet roads (tourer). You have to push quite hard to get up enough speed to get through the weakest part of the stroke (when the pedals are vertical) so simply starting gently isn't an option either. Because of the grip, this heavily depends on the surface, so it's not just about the bike.


What tools to bring for road side chain maintenance I've been making a lot of kilometers recently. Although I do proper maintenance on my chain (replacement, cleaning and lubing). It can always happen that one of the links break, or that I am with someone, or encounter someone that has problems with the chain. I always carry my Topeak multitool, which contains such a chain link removal tool as well (don't know the word for it).

However, it is probably not the best tool in itself for  emergency repairs. I am considering to bring one or a few extra pins, such that I can do a repair. At the same time I also read about these easy in use links that you can also use. My question is: what do you recommend me to bring on my bike trips in addition to what I already got, and why?

Taking a piece of chain can be useful one day, but what is the likelihood? I say take a multitool with a chain-breaking tool, that you verified you are actually strong enough to use (some have very small leverage) and a quicklink. That's good enough for normal rides, unless you are going for a week on your own. Many other people don't take anything. Assess the dangers yourself. On a road bike you are less likely to do more than breaking a single link, on a mountain bike it may be more likely, depending on the kind of your riding.

If you are so worried that you need a full piece of chain you could also nee some spare spokes, tools for removing your cassette (including a wrench with enough leverage) or even a spare rear derailleur (apart from the usual spare hanger). And your torque wrench in case your stem or saddle becomes loose. Ad you will find out it is simply impossible to stuff everything in your saddle bag. Especially if you planned to take two spare tubes as well.


Will Shimano B01S brake pads work with m675 slx I recently started cycling regularly again after 3 years or so and need to change some parts. It's infuriatingly hard to find information on compatability for parts now that CRC can't sell Shimano stuff. All I get when searching this in Google is 10 different listings from sellers on amazon, eBay, and who knows what else.

Anyway, B01S is half the price of J02A, and I definitely don't need the fins. Does anyone know if B01S will fit on M675 slx brakes?

B01S resin pads is one option you have for pads for this model of brake caliper.  If it is longer lasting metal compound pads you seek for the SLX brakes, Shiimano spec sheet lists the  F03C as the compatible metal pad.


Can I fit slightly different tyre sizes My current bike tyres are 26 x 2.0 (Manufacturer fitted tyres)

Is it possible to fit 26 x 2.1 or 26 x 1.95 on these wheels or is this going to cause an issue?

Slightly smaller is fine

There's really no possible problems going just a wee bit smaller. Even going much smaller would probably be fine.

Slightly larger is probably ok

With the original 26 x 2.0 tires on the bike, check the clearances. Remember that a 2.1 tire will be both wider and "taller". Look at how much space there is around the tire at the fork crown, where the tire is close to the downtube, where the tire passes between the seat stays, where the tire passes between the chainstays, where the tire gets closest to the seat tube... As long as there's room for a wider tire, it'll be fine.

It's really common to change out tires for slightly different sized ones.


How do I remove a bottom bracket? I have managed to remove the threaded locking mechanism of this bottom bracket. However, I can't get the bracket out. I have tried to just bang it out, but it doesn't move. I don't know what else to do. ideas? help.

Look at the thread on the exposed cup. That tells you which way you need to turn the cup to get it out (there are multiple standards here, and one of the key differences is that some use left hand threads instead of the usual right hand). It looks to me as though the top of that cop should rotate to the right to remove it, in which case it is a left hand thread.

You should be able to fit a spanner onto the raised part on the cup nearest the camera in that photo. Preferably a large spanner with nice sharp edges on the jaws, since the flats are not very deep.

The other side possibly has a couple of holes rather than more flats like this side. In which case you can use a pin spanner or a hammer and chisel to tap it out. Or, as Sheldon suggests, just put a big bolt through and use that to turn the cup.


Selecting spoke lengths I'm planning to build a new wheel, using a Velocity Synergy OC (asymmetric) rim. When I calculate spoke lengths using the Edd spoke length calculator I get these lengths:

Drive Side: 293.9 mm

Non-drive Side: 294.7 mm

So, the drive side seems easy, I'll use a 294 mm spoke. But what about the non-drive side, would it be better to round up to 296 mm or would 294 mm work? How do you decide when it is better to be a bit long or short?

I would round to 294, since that would keep difference from theoretical less than 1 mm, and as bonus left and right would be of same length which means you have to stock only one size for replacements.


Upper pulley on rear derailleur (jockey?) very close to cassette? Useful information:

The bike is currently on the smallest sprocket and smallest chainring
(smallest rings by pedals and rear wheels incase my terminology is
wrong).
Rear wheel is currently not centered.
I've been looking at the bike upside-down
The chain is the correct length, tension, as far as I can tell, is as it should be, and all other parts are correct
The derailleur was properly adjusted before the wheel was removed and then reinstalled, and neither the cable nor the screws (H,L, or the other one) have been touched.

So right now the upper pulley is very close to cassette (specifically the smallest cog on the cassette, where the chain also is right now). It is almost close enough for the pulley (well the teeth of the pulley I guess) to be engaging the same length of chain that is on the cassette.

Is this incorrect? Also, out of curiosity, would there be an issue if the pulley and the cassette were engaging the same length of chain?

The current position of the derailleur looks a bit like in the picture below, except with the upper pulley a little closer to the small cog on the cassette.

(Picture taken from http://cdn.mos.bikeradar.imdserve.com/images/news/2012/10/30/1351601204145-dusw1th1s7gr-960-540.jpg)

Thanks.

Note: I'm not riding the bike as it currently is (nor have I yet tried). I've been working on it (and am almost done, just have a bit more to do like center the wheel and lubricate some parts), but I noticed this and decided to ask, in case I did something wrong or need to adjust the derailleur.

Several things coming to mind when I read this.

a) If the wheel is not centred, its not sitting in the drops correctly. If its not sitting in the drop-outs correctly, the axle to derailleur mount distance and the angles of the derailleur to cassette are off.  There is little point looking at derailleur adjustments unless the wheel is centred.

b) Smallest smallest is cross chained. Performance of derailleur in this state is relatively unimportant

c) The derailleur was properly adjusted before the wheel was removed.... The thing that affects the clearance of the jockey wheel is the B screw - was this changed?

The first thing to do is put the wheel on straight, remove the cross loading by putting the dérailleur onto the largest rear cog, and if needed, adjust the B Screw.