How do I determine if my front wheel is warped? I've noticed that as I ride my bike, my front wheel/tire appears to wobble back and forth. I assumed that the wheel was simply a bit loose, but as far as I can tell, it isn't loose (or at least not very loose).

It does appear, however, that my front tire is ever so slightly warped in a sort of Pringle shape.

  Is there a way to determine for certain whether or not the wheel is warped?

Follow-up questions regarding how to solve the problem will likely appear soon, but that is not the point of this particular post.

Lift the bike up and spin the wheel while you watch it closely, at the top of the fork.

The tire should remain centered between the two sides of the fork as it spins, and the surface of the tire should not move closer to nor further away from the top of the fork.

If you have rim brakes, the rim should remain in exactly the same place relative to the pads as it spins.

In cycling vernacular, you need to check if your wheel is true.

This video covers the entire wheel truing process:


Swapping 1994-95 Diamond back sport response components out My Diamondback sports response is from roughly 1994-95, The Shimano STX shifters are completely done on it. I would like to not purchase a new bike seeing that nothing is wrong with this frame. Is there a new model of shimano shifters that would work? or any suggestions on swapping out all the components for this bike?

It looks like it runs a 3x7 Shimano mountain drivetrain. You can get new shifters such as the Shimano ST-EF51's (the 3x7 version; which are switchable between V-brakes and cantilevers -- see manual for details) or the SL-M310 (in the 7 speed version for the rear, triple for the front; add your own brake levers if yours are integrated with the appropriate cable pull). I'd probably opt for the SL-M310's personally -- I've had the ST-EF51's briefly and the quality left something to be desired.

Alternatively, you can buy the Microshift DS85-7 (grip shifts) or TS38-7 (trigger shifters) and add your own brakes. Or SRAM Attack! grip shifts.

If you're really cheap, just buy a set of thumb friction shifters. Any ones will do. These aren't indexed so you have to move them into the right position to shift based on feel.

I'd also suggest replacing the cables while you're at it.


Identifying bottom bracket type Looking to buy an eccentric bottom bracket for adjusting the chain tension, however before ordering need to make sure it is compatible with my bb shell.

There are following types of eccentric BB:

For 1.37” x 24T & Width 68mm BB Shell
For BB Shell I.D 46mm & Width 68~73mm (JIS BB Only)
For BB Shell I.D 46mm & Width 68~73mm (Shimano & SRAM Compatible)

Need help choosing the right one (i can do additional measurements if needed)

Looks like you have a standard 'English' or ISO standard threaded bottom bracket shell. These have 1.37 inch (34.8mm ) diameter threads of 24 threads per inch. Common width for road bikes is 68mm You can easily verify this by measuring the inside diameter of the shell and the width.
You might also have a 'Italian' threaded shell that has slightly smaller threads. See https://www.sheldonbrown.com/cribsheet-bottombrackets.html
For 'three piece' type cranks where the axle is part of the bottom bracket you also have to consider the axle length. Cartridge bottom brackets typically come in a range of axle lengths and the correct length must be selected so that the crank chainrings have the correct chainline (distance from center of the frame to the chainring).


difference between rack mounts and fender mounts? is there a specific way that bike builders build mounts/eyelets for racks for panniers and eyelets that hold fenders? I'm specifically thinking about eyelets on the rear dropouts. I know that if a manufacturer doesn't want a rack at all he or she won't put mounts on the seatstays, but is there any structural difference between the two?

There's no difference that I'm aware of.

My bike has 2 sets of eyelets, and I have a fender screwed into one set, but I could just as easily use the other set. I suppose the same could be said of using either set for rack mounts.

Looking at it from a structural point of view though, it would probably depend on the bike and the materials it's made of. But if it's in the right place, I'd probably give it a go :)


Counter-intuitive steering in crosswinds with hands off the bars It should not be surprising that it is difficult to ride in a straight line with both hands off the handlebars when there is a crosswind.

However, I find it most unintuitive, that for example if there is a crosswind from the left, if I let go of the bars and try to keep my body upright, the bike wants to turn sharply to the left (into the wind). To counter this, I have to lean my body to the right, as if wanting to turn right.

I would have thought that the wind pushes me to the right and I have to steer left to keep going straight. Why is this not the case?

If the wind is from the left, you need to lean to the left to stop the wind blowing you over to the right; leaning left makes you turn left.


Loose spokes after truing a wheel I badly bent my rim going down a huge hill and bouncing all over the trail. I've managed to get the wheel much more true to the point where the wheel is ridable. However, due to the extent of the bend, the spokes on one side are really right and some on the other side really loose. There's still some buckle so I'd need to tighten up the tight spokes more to remove the buckle fully. Does the wheel need a few casual rides to allow the rim to move?

Jobst Brandt's The Bicycle Wheel tells about repairing this failure mode in the following way:

In a soft failure the rim has a smooth and continuous bend, and some of the
spokes have become loose. If the wheel is deformed laterally more than ten
millimeters, all nipples, even on spokes that have no tension, should be
unscrewed two turns before attempting to straighten the wheel. Straightening
the rim by bending it without first unscrewing the nipples would, in effect,
straighten and tension the wheel at the same time. Straightening makes the rim
yield and take a new shape. When yielding, it will deform not only in response
to the straightening forces, but also to the spoke tensioning forces. If the nipples
are not unscrewed, the combined forces would cause kinks in the rim at each
spoke.
To repair such a bent or collapsed wheel, first loosen all nipples about two turns
(one turn if the wheel was loosely spoked). Lay the wheel on its side with the
largest wave toward the floor and press down on the rim on either side of the
bend. If necessary, repeat this process turning the wheel over until the rim is
reasonably straight. Now place the wheel in the truing stand for tensioning and
truing. If the misalignment is still more than ten millimeters, repeat the
procedure on the floor while gradually tensioning the spokes. Now the wheel
can be trued as previously described. Because straightened rims usually have
nonuniform spoke tension, the wheel may not stay true.

I suppose you didn't follow that procedure but rather trued the wheel in a truing stand only? Loosen the nipples as directed, straighten the rim and retension and re-true.


Replace threadless headset retained bearings with sealed bearings? I have a rather simple threadless headset in aluminum frame, and forks. It's creaking quite a bit, I think I'll replace the bearings and races. It has "retained" bearing rings (semi-loose) and cup races. I was wondering if it's possible to replace these with a sealed type bearing set?

Yes, it is possible. The headset compatibility is determined by steerer tube and head tube dimensions. The type of bearings inside does not really matter, and the difficulty of getting spare parts for sealed bearings or maintaining loose ball bearings are both exaggerated.

When replacing the headset, check the condition of the frame: if the creaking is because of deformed head tube, a new headset will not help.


FEM: How to Design weight-distribution in bike prototypes? Inferio! No-one can understand this bloated question here, now more focussed.

Suppose you are doing a new bike. How can you be certain that some critical point won't get too much force and the right parts gets the force that is then again supported by the ground? Of course, everyone here has played the wonderful bridge construction -game and knows that weight-distribution requires proper analytical reasoning. I think there are some multi-variance-something-methods to investigate it. Anyway, just skim-read a book and they give many different formulae (apparently numerical approximations) for different kinds of attachments (or welding points or anything you call it). So I don't try to underestimate the hardness to design proper weight distribution. Any design hints welcome.

What do you mean by weight distribution? Most of the mass is the rider, and the rider moves.

Bicycle construction is very experimental. Analysing dynamic forces is complex, partly because most of the mass is only loosely coupled to the bike. With most mechanical structures the loads are more predictable, for a bicycle you only have to look at flatland bmx riding to see what a bicycle has to handle. A simple case to think about is the rider leaning into a corner. The forces are not vertical with respect to the bicycle, but at an angle. So you have side loads on the wheels and frame.

The usual approach for commercial bikes is to overengineer and test. Manufacturers of racing bikes sponsor riders partly to have crash test dummies to ride experimental bikes. They keep making them lighter until something breaks, then add a bit back. Or not, they might just choose lighter riders or replace the frames more often.

For homebuilders you can deliberately build light and see what happens (as I did with One Less Ute)

Simulating the loads in software will be complex and I think you'll end up trimming your Monte Carlo parameters to the point where you're not getting a very representative sample (or you're buying a lot of supercomputer time). The extremes that I have done on a rigid diamond frame bike include: dropping ~3m onto a gravel road at ~40kph horizontal speed; riding down a twisty gravel road (~10cm high to low points) at 60kph with 15kg on the front panniers and 30kg on the back; riding 450km of sealed road with 20kg front, 40kg rear, 20kg backpack. I weighed about 80kg when I did those, the bike weighed less than 20kg.

My approach is to assume that the entire weight of the bike + load can be applied to one wheel with the bike anywhere from horizontal to vertical. Then allow for some bouncing. I try to get roughly 60% of the weight on the rear wheel when the ride is seated and there's no extra luggage for normal road use. Load bikes don't obey those guidelines at all.


Why are some bikes sold without pedals? At the risk of sounding like a bumpkin, why do I see some bikes sold without pedals or at least pictured without pedals? Is there some kind of benefit to buying pedals separately? Do some people take their pedals off the bike when not in use, like they might take off their wheels or seat post?

Higher-end bikes are expected to be used with clipless pedals. However, there are several different standards for these pedals, and all of which have a different type of cleat that fits in them.

Most cyclists tend to stick with one of these standards across all of their bikes, so they don't have to have multiple sets of shoes. Thus higher-end bicycles typically are sold without pedals so that the customer can select the style of pedal that matches their existing shoes.


Chain skip options on vintage 'frankenbike' I have a late 80s Bianchi Volpe which came with Sakae Ringyo SX cranks and bb, SunTour barcon shifters and derailers, and SunTour chain.

The freewheel was aftermarket 7 speed and never rolled well so I replaced it with a Shimano 7 speed available at my LBS.

Everything was working well and the drive train was low noise and decently shifting despite the frankenbike nature and problems others have had, specifically that SunTour shifter throw and cage travel is not SIS compatible.

Recently I replaced the chain with a SRAM 9 speed based on reports that the narrower chain is even better on noise and can confirm, drivetrain is much quieter.

But now the chain skips under load. I know cog wear can be the source of this skip, but neither the chainwheels nor freewheel appear to have that high wear, and the original chain was only a few hundred miles past the Park Tool's ".75" indicator mark.

Attached is a picture of the filthy cranks (Chicago winter salt and sand included).

If I do need to replace the two largest chain wheels, must they be SR? Other brands seem more widely available, assuming BCD matches.

Edit: Picture for real this time.
Dirty freewheel:

First, I'd trouble shoot why the chain is skipping. Does it only happen under heavy load? Does it always happen in the same place (maybe a stiff link)? Does the derailleur do something funny?

If the BCD and bolt pattern matches, stick whatever chainrings you want in there (subject to front derailleur constraints on chainring size + tooth gap). As for if your chainrings are worn or not, the picture isn't there, but there are plenty of other questions (see sidebar or search) on this SE to check if your chainrings or cogs are worn beyond.

While using a 9 speed chain on a 7 speed cassette should work, it will likely be a bit sloppier than using a 7 speed or 8 speed chain (they are narrower than the chains that the 7 speed cogs were designed for). They're also pricier. So, I'd also go back to a 7/8 speed chain in the future.

The change from Suntour freewheel to Shimano freewheel shouldn't really have caused any problems other than maybe some minor adjustments (unless you're running a microdrive drivetrain).


How to deal with lock that keeps jamming? I have a kryptonite U lock and lately it's been sticking a lot while trying to turn the key. Usually I can eventually get the key turned. It was getting worse though and a few days ago I (unable to find any lube/wd-40 etc) cleaned it out with soap and water which seemed to help a great deal. I also started being very careful to make sure the little key-hole guard engaged. Last night when I was totally unable to get my bicycle unlocked and had to leave it there and walk home. The key would fit into the lock and turn half way and then stop. I'm going to go try and pick it up now, but I don't know the best way to try and make sure this doesn't keep happening. It's winter here and I wonder if that might have something to do with it.

Edit: I ended up at the hardware store and the guy there (who had built his own bike in his garage, conveniently) recommended jig-a-loo. This made the lock move really well but I still couldn't get it open. This is when I noticed that my key was twisted (From trying to force the lock probably). I flattened the key back in a clamp and was able eventually to unlock it, but I can't seem to lock it again, so I ordered new keys. I'll have to wait till they come to see if that solves anything or it's actually a problem with the lock...

Edit again: Some graphite and new keys seemed to do the trick!

You can follow the advice in this thread to get your lock off, although my guess is that the lock was either damaged from washing it or water has frozen inside the lock.

Once you get it off, if the lock is damaged, Kryptonite has a lifetime warrantee on their locks. I'd call them up and ask if they'll replace it.


Has this rim strip expired? I have 2 unused rim strips. Along the edges and on the surface there are brown marks (patches, streaks, blotches).

2 images (I cannot improve the resolution)

Observations

Both strips were stored hanging vertically (i.e. not folded nor rolled up).
When I place the 2 strips over each other, I see that the edge marks overlap, i.e. the strips have the same brown edge marks in the same positions.
Overall the rim strip is smooth. The material is not brittle. There are no scratches nor nicks.
Seems like the brown color has steeped into the plastic.
The size written on the rim tape: 32 559
There is a number which looks like a manufacture date: 06/05
Manufacturer: Schwalbe

Questions

Is this rim strip beyond its use-by-date, i.e. if I use it will it need to be replaced soon?
Perhaps an alternative question: what does a rim strip look like when it is in need of replacement?

This particular rim strip absorbs color from everything, and it is not a problem. Mine have turned green in use from something leaching from tubes.

In general, rim strip should be replaced if it splits, stretches deep into the spoke holes or exposes the spoke holes. Discoloration happens, but since rim strips aren't usually visible this is not much a problem.


Did I damage my frame by removing a sticker? I’ve just bought a new bike with a matt finish, and peeled off a sticker from the top of the frame - but this revealed a shiny finish underneath.

Is this a problem, and do I need to do anything about it?

I’m wondering if the frame is now vulnerable to weather etc. on this spot, or if there’s a risk the coating could start to peel away from the edges.

The shine is likely the residue from the sticker adhesive. I would apply some rubbing alcohol on a soft cloth and see if it comes off. As you haven't damaged the actual finish, it will be fine. I had a similar finish on a Diamondback Response. After its' first wash I waxed it. I thought I had ruined the matte finish. When the wax wore off the original finish returned.


How do to tension and true a rear wheel with a warped rim? So, after doing extensive research and youtubing on bicycle truing and wheel building, I decided to completely de-tension a rear wheel on one of my old bicycles and try bringing it back up to tension/round/true/dish.

But, I ended up taco-ing my rim pretty badly in my truing process and rounding two of the nipples.  I guess my spokes were too tight or something.  I was just turning, turning, and then boom, taco'ed.  Now I know, I guess.

So, I detensioned all the spokes again to try and start over, except this time, I noticed my rim was physically deformed.  it wobbles and is out of lateral true pretty badly with no spoke tension on it.  I tried bending the rim back into shape, and got it slightly better, but I think it's as good as it's going to get.

I can't really follow any of the youtube or online tutorials now, since my relative tension between spokes is going to be very disparate because of the rim, and all those tutorials assume (rightly so), you have a good rim to begin with.

I was hoping someone could list a methodical way of bringing such a rim back into tension/true/round/dish-ness.

Thanks everyone.

You need a good book, and, unfortunately, no really good books on bike maintenance have been written in about 20 years.

Two that you might be able to buy used are:

Effective Cycling
By John Forester
MIT Press, 1984

The All New Complete Book of Bicycling
By Eugene A. Sloane
Simon & Schuster, 1980

Both contain decent discussions of wheel building and truing.


Joining Shimano chain with pin - which link-type should "lead" (take the power) I'm pro-actively replacing the chain on my son's bike (the first time I neglected this cost me dear for replacement of derallieur, cassette and cranks at the LBS) which is used daily for commute to school (about 8.5 miles/day round trip).  The previous chain was a KMC which came with a quick-link, this time I am back to the original.

The new chain is Shimano 8S CN-HG71, and comes with a connecting pin rather than quick-link.  I'm looking at the Dealers Manual DM-GN0001-23-ENG.pdf pages 68 onwards.  I have all the necessary tools.

On page 70 it states:
As illustrated in Fig. [A], we strongly recommend to set the connecting pin in the hole of the outer link on the front side in the direction of travel.
The chain’s level of strength is enhanced compared to the method in Fig. [B]

This is accompanied by an image but unfortunately, rather than clarify, this has left me with a level of doubt.

The picture shows the chain broken below the crank therefore travelling right-to-left, if the figs. [A] and [B] correspond to this then they are the opposite way around to what the words suggest.  Or is the pulling-force being applied from the right-hand-end of those diagrams (so they are not a direct zoom-in to the crank diagram, despite that being suggested)?

Image credit: Shimano

The way they've worded and shown this in diagrams has always been a little nutty. You can pretty much see what they mean if you max zoom on the full res pdf though.

You are looking at the drive side of the bike. You are holding the chain stretched end to end between your hands. Your left hand holds the end that terminates in an inner link, your right one with an outer link. Put the outer link end on the crank and through the front derailleur as applicable. Put the inner link end through the rear derailleur. Do your sizing on the inner link end such that you're still left with an inner link when done. Then connect it all with the one-time pin.


Can I get smaller tires without changing my rims? I currently ride a hybrid that came with 700x32c tires. Can I swap out a narrower tire without changing the rims, or do rims only fit a specific size of tire?   How small can I go before I have to buy new rims?  I hear having narrower tires makes you go quite a bit faster.  Does it really help that much?

Most 700c rims will work with essentially any size of tire. Yes, smaller tires generally reduce rolling resistance a little, but unless you're road racing, it's rarely worth going below about 700x23c, IMO. Also note that just being smaller doesn't necessarily mean lower rolling resistance -- one brand of 700x19c might have higher rolling resistance than another brand of 700x20c, for example.

The big change (if any) happens when you switch to slick tires (and most 700x32c tires have fairly substantial tread if not outright knobs).


Presta Valve Core bent Today I was trying to pump my bike tire using mini pump. It has presta valve and after pumping i found that I've bent the valve core by about 5 to 8 degree angle. I tried to bend it back enough for it to be somewhat straight. My question is, should I replace the core? Should I be worried?

It happens, especially if you remove the pump head not perfectly vertically or you move the pump head while pumping.

You can avoid this by using a bit of hose on the mini pump like on this mini pump

or bracing the head of the pump while pumping.

Its not the end of the world if the valve core is bent -- I've run tubes for years with slightly bent valve cores. Note that at some point it may break (and you'd need to get a new tube then). The presta valve only lets out air when you press down on the valve core, which you can't do once you tighten down the nut (even if it doesn't sit flush with the rest of the valve and hits the stem at the angle, you can't push the nut down anyway to let out air).


Preventing frozen brake cables This response to another question provides a wealth of info on winter riding preparation, but doesn't mention any techniques for preventing cables, especially brake cables, from freezing.

Is there a particular type of lubricant that is especially effective in preventing frozen cables?  Would WD-40 or the like be appropriate?  What other techniques are useful?

Frozen cables happen because you've got moisture in the cable and housings. This can happen fairly often if you bring your bike inside after they've been wet and then have it back out long enough for that moisture to freeze. Two things can help.

First, make sure your housing covers as much of the cables as possible. Second, use a cable lubricant, which will help keep moisture out.

WD-40 should not be used on brake systems, and should only really be used on your bike as a temporary lubricant (to remove seized parts, for example). It's primarily a solvent and a de-greaser. You actually want grease on your cables.

EDIT: I was having trouble adding a comment below to answer your questions:

I use TriFlow, which is a light synthetic. You'll only need a few drops at a time, so don't worry about buying in bulk.

The other lubricant you could try, and I've seen some people in bike shops do this, is a waterproof grease, the same stuff people use on their bearings and threads.

Generally, I look for light oils for my cables, as others tend to gum up in the housing, but they should be good in a pinch.


No space inside the house, where do you store / secure bike? I live in the UK. At my house, I don't have much space, I have a drive-way but no gate surrounding it. Here's an image:

What are my cheap storage options for a mountain bike (voodoo bizango).

Thanks

You can get wooden storage sheds for bicycles for around £150 - £200.

You'll also need something to secure the bike to. You could install a ground anchor, either the screw in type:

Or the type that you embed in concrete:


Is it worth it to repair or is it better to buy? I found an old bike on my grandpa's house and since i am in need of a decent bike i wanted to know if the bike was good enough to be refurbished (new gears, pedals, brakes, tires etc.) or if would be better to just buy a new one.

Here's a few things you could do-

Get a new seat and seat post.
Ride the bike and see if anything sounds or feels amiss. Places to look out for are the moving arts like headset(handle), the drive train and the brakes.
The drive train seems to be in prime condition except for rust. Spray some WD-40 or equivalent rust remover on anything thats rusty and make sure you wipe off the extra cleanly. Then lube the whole drive train.
Your brakes will need replacing for sure, best not to take risks with safety.

You will have to decide the worthwhileness of the project for yourself. Money wise it won't cost much more than $50 (~20 for the seat, and the rest for brake pads and other implements like WD-40 if you don't have them). I would personally do it less to save money but more for the learning that would be gained from doing it. But the importance given to learning experiences differ from person to person and its up to you


What bikes will be used by the competitors in the Mountain Bike Olympics? I'm just curious to know what bike models and setups will be used by the competitors? Is there any data out there on the web?

There was a test event on the Hadleigh Farm Mountain Bike course which will be used for the 2012 Olympics. There are various photos and videos of the event which show the bikes being ridden:

Videos on YouTube

Photos from The Guardian

Photos from Cait Elliott

From looking at these:

Everyone seemed to be using carbon fibre frames
Most riders used a hard-tailed bike, although some had full suspension
There was a mix of wheel sizes (I assume 26 and 29 inch)

You can make out manufacturers names on many of the bikes and in some cases on individual components if you're particularly interested in those.

Edit - a few things I picked up from the commentary on the 2 races:

In the men's race there were 3 different sizes of wheel in use - 26, 27.5 and 29 inches.
Most of the riders opted for a single chainring, with the rest using 2.
Suspension travel was around 100mm with the suspension set hard.
Tyre choice was small lugs to give better grip on the rocky sections.
At least one rider was using a "lefty" fork.
Some riders were carrying gas canisters to deal with punctures.
Bike weight was around 19 pounds (8.6 kg).


Bicycle Seating Posture Ergonomics Road bikes have a forward bent seating posture, mountain bikes have a straight seating posture.

I was wondering which of the above seating postures (of road bikes or mountain bike) is better for back bone?

Whether any of these seating postures could cause back pain, slipped disks etc?

The number of comments to your question is becoming quite large, so I thought I'd roll my comments up into an answer (of sorts).

You ask whether the seat postures could cause back pains, and whilst I have no specialist knowledge in this area, I'd have to say from a purely empirical viewpoint that the answer must be "no". A lot of people ride a lot of miles on a lot of days, without suffering long-term pain.

But it's not a blanket "no", there are caveats. For example, if you have a badly-fitting bike, this can quickly cause pain.

Plus don't forget, under the large umbrellas of "road bikes" or "mountain bikes", there are many different frame geometries which offer many levels of comfort.

For example with road bikes, at one extreme there are bikes designed to be ridden by professional racers, whose geometry will sacrifice comfort for efficiency/performance.

At the other extreme there are, for example, touring bikes which are designed with a more relaxed geometry, so as to be comfortable for riding all day, over several days, and carrying a load. There are a gozillion bikes in between, and the story is repeated for mountain bikes.

Example: two different road bikes (same manufacturer). The first (left/top?) photo shows a bike from their "road" [i.e. racing] range, the other from their "touring" range. You can see the different frame shapes involved. (The two bikes look pretty much to be on the same scale, certainly they both run 700 tyres.) But if you look at both the vertical and horizontal distances between the saddle and handlebar, hopefully you can envisage that the rider of the left bike would have their back more horizontal (efficient but uncomfortable), the rider of the right bike will have their back at maybe 45° (give or take), a far more comfortable position.


What are some good flat pedal shoes for XC racing? Like the title says, I'm looking for some recommendations on good flat pedal shoes. This could include ones with an SPD or other interface that has removable clips. I'm currently riding with a set of 5.10 Freeriders, which offer great traction and grip to flats, but are really heavy.

At some point, I'll probably have to force myself to race clipped in, but for now I love my ability to quickly dab and destroy any downhill sections.

Quick breakdown of what I'm looking for:

Light weight
Grippy/good traction
No clips/removable clips

Five Ten Freerider VXi Elements - 398 gram
Five Ten Freerider - 399 gram
Giro Jacket - 416 gram
Shimano AM41 - 420 gram
Teva Links - 440 gram
661 Filter - 680 Gram

So basically, all the available (excluding high-top shoes) flat pedal shoes weigh the same. You could theoretically shave 1 gram by switching to the Freerider VXi Elements, but that would hardly be worth the money.

An alternative could be some light weight skate shoes, but then you would probably loose out on grip and the weight savings would probably still be negligible.

And for comparison Diadora X-Trail 2 Carbon SPD shoes are 335 gram.


Bike not changing correctly between two gears I have only recently started riding to work and I've been given a bike by a friend which is in reasonably good shape.

For the way things are working out I keep the front gear in the same position and change the back one between 4, 5 and 6.

The trip is very hilly so I like to switch over to 6 as I near the top of a hill so I can continue pedaling as soon as possible at the base of the next hill.

However, the bike changes quite readily between all other gears 1 - 5, except going up from 5 to 6. Going down 6 - 5 works fine. This means more effort when trying to go up the next hill. Sometimes the gear kicks in just before I want to switch back down to 5 again.

There is also a 7th gear on the back that I don't use, so the 6th is not the highest choice.

This problem occurs regardless of if I'm going up, down or on a flat grade. It also doesn't help if I try switching back down to 5 and trying again, it just seems to kick in randomly.

Any suggestions on what I can see could be causing this.

How many miles on this bike?  If over 5000 miles (8000km) then your rear gear cluster may be worn out.  Your symptoms are most strongly suggestive of that.

Otherwise, the first thing to do is to clean the derailer real well.  Lean the bike against a wall (derailer facing you) outside somewhere where a few oil stains won't be a problem.  Shove some newspaper or cardboard up behind the derailer and drape it over the tire, to keep stuff from dripping on the tire.  Then spray the derailer well with a spray solvent (WD40 in the US) and scrub it with an old toothbrush.  Dry the derailer well with an old rag, and lubricate with chain oil.

With the derailer clean, swivel it back and forth by hand and notice if it seems to be twisting in parallel with the chain and sprockets or is perhaps bent so that it goes at an angle.  If it seems bent (which happens from dropping the bike on its side) then the "derailer hanger" probably needs to be straightened.

Also, pay attention to the shifters and cables.  A little spray lube in the shifters and down the shifter cable housings is generally all that's needed here, unless the cables are badly corroded or beginning to fray, in which case they need to be replaced.  Be careful, though, about what sort of lube you put on the shifters as most now have plastic components that can be damaged by strong solvents.

And, of course, it's probably time to adjust the derailer, but that a whole different post.


Bolt came out of both clipless cleats I recently got clipless pedals and the LBS i bought the shoes at set up the cleats for me. After practicing to make sure i felt good about unclipping, today i did my first ride with the system 25-30 miles and about 2/3rds of the way through i found i couldn’t clip in at all. When i got home, i looked at the cleats and noticed one of the bolts came off each of the cleats? Is there any reason this might have happened?

Those bolts need to be secured very carefully.

Use a torque wrench set to 5Nm to tighten the bolts, alternating a quarter turn at a time between them.
Use plenty of threadlocker on the threads.
Use grease or antiseize on the underside of the bolt heads. It’s also best to put some under that “8” shaped piece so it doesn’t rust onto the cleat.
Clean the sole of the shoe well with alcohol. Oils under the cleat will obviously help it slide around.
I also like to apply liquid candle wax or some other lipid on the exposed parts of the cleat mounting plate to prevent rust.

This may sound excessive, but I’ve never had an issue following this approach. On the contrary, every example I’ve seen of cleats falling off starts with “I just threw the cleats on carelessly”. Treat your cleats and cleat bolts with respect: they carry a lot of load and a lot of responsibility. You’ll be glad you did all this prep work when it comes time to replace your cleats three years later and the bolts are still firmly tightened, but also aren’t frozen in place with rust.
You should definitely bring this up with the shop. They obviously failed the cleat installation. Depending on how chewed up the soles are under the cleats, you might have a case for a new pair of shoes too.


Clicking noise when cranks rotate I've got an old `86 Raleigh fixed gear bicycle that is making a loud clicking noise when the cranks rotates. It seems to have just started doing this today. I'm looking for someone who, maybe has experienced this type of noise with a bike before, that can possibly point me in the right direction to fixing it.

Both bolts on each side are stripped so I'm not sure how I'd get it apart to see if it could be the bottom bracket, if you have any ideas on how to do that, that's appreciated too.

The only thing that I can think of that could possibly be a variable in this is yesterday I sprayed some pb blaster down my seat post and into a little hole in the frame to get my extremely stuck seat to come loose.

Anyway...here's a video of the noise:

That sounds like the bottom bracket bearings to me.

It could be the chain, but you can eliminate that by loosening the rear wheel and slipping the chain off the chainring.

It's not chainring bolts as these only creak under load. It's not the bottom bracket cups for the same reason.

You appear to have a loose ball bearing bottom bracket with an axle with square tapers that the cranks fit onto. I linked a video below that shows how to service this type of bearings. When you say 'Both bolts on each side are stripped' I think you mean the end-caps. You should be able to get those off by jamming something that will engage with the rounded off hex hole. I'd try a large screwdriver with a tapered head.


How does a bike 'degrade' whilst unused What (if anything) will happen to a bike whilst it sits unused, that wouldn't happen to it whilst being used for a work commute over the same period?

Suppose I take a 3 month sabbatical and leave my bike locked up and secure, in the same place that it would normally be (outside, moderately exposed to the elements). When I come back 3 months later would I have to do/check/refurbish anything that I wouldn't have had to do from just using it daily for 3 months (and still outside the whole time)?

Is the answer different if it's "2 years", or "3 weeks" rather than 3 months?

Of course things rust in normal use. Still, rust without moving is worse, as things stick together.

Even if the chain is generously oiled (more so than normal) before storage you'll get rust and probably stiff links.  Any gears made out of normal steel will also rust. (A light coating of spray oil will reduce but not stop this. I use GT85 on my outdoor bike; make sure you don't get it on the rims).

If your rims are steel (mainly old bikes) they may rust under the chrome plating.

Brake pads and rims are likely to be dirty, which will affect braking performance.  I'd clean them with plain water at first; if greasy use alcohol.

Most brake cables are stainless; but, especially on old bikes, there are braking components that aren't.  A good hard squeeze of both levers before you start riding would be a good idea, and try the brakes cautiously on the first ride before you get to traffic.

The tyres will need pumping up.  When you do so, check for cracks in them.  And test the pressure again soon afterwards, as the tubes may not hold air as well as you think.  It may be a good idea to pump up the tyres to slightly higher than the stated max pressure, then leave the bike a few hours before reducing the pressure to normal and riding.

Gear shifting components may well rust.  I've found rear derailleurs to suffer more than front derailleurs. Again storing dry (of water) and oiled will help.

Some locks rust badly.  If your lock gets too rusty you may not be able to open it.  Some bike lock manufacturers recommend oil -- if yours does, follow that recommendation.  Keeping the keyhole downwards may help, but water can run into locks from other directions too.

A non-mechanical factor:

Don't assume it's as secure left in the same place for months (and certainly not years) as it is left overnight.  The landowner may have a good (or bad) reason to remove bikes which appear abandoned.  Or a thief might think: "no one will miss that; I'll take it".  You also can't neglect the possibility of vandalism or careless damage, especially if a bike appears abandoned.

The difference in the 2-year case is that the degradation is more certain, leading to your bike being more likely to be scrapped as abandoned.  If the bike isn't special enough to take with you, it's probably better to sell it and replace it when you get back.  This is because, after a couple of years it will probably need more than it's worth spent on it.  A few weeks doesn't seem much worse than a weekend if you oil everything and can keep the worst of the rain off (I do this several times a year under the edge of a canopy on a station platform).


Wheel building - how to tighten spokes to have perfectly equal tension So far i figured it out following recipe for perfectly adjusted front rim:

Assemble the wheel leaving tiny portion of thread visible outside nipple for every spoke.
Tighten each nipple equal number of 360 degree turns (e.g. 6 turns out of 12 total).
Keep adding equal number of 90 degree turns to each nipple until you get equal tension of about 100 kgf (1000 N) for every spoke (remove spoke tension)
True the wheel (remove spoke tension)
Adjust the spokes again until you get equal tension of about 100 kgf (1000 N) for every spoke (remove spoke tension)
Keep repeating step #4 and #5 until you get equal tension for every spoke while rim stay's true.

Problem is that step #6 has to be repeated too many times, is there a faster way or can you advice any better sequence for wheel building?

Don’t obsess over it. Perfect is the enemy of good enough.
Something like ±10% spoke tension deviation is perfectly fine. For lateral and radial truing about ±0.5mm is fine. With lower quality (or damaged) components it will be harder/impossible. On the front wheel you have more margin since it’s symmetrical, has less spoke tension and is less prone to broken spokes. On the rear wheel asymmetrical rims can help because then you need less tension on the drive side and can put more on the non-drive side. Again giving you more margin (and/or a stronger wheel).
Experience and a methodical approach will help you get there faster. For example when you find an area which is laterally out of true you shouldn’t only loosen or slacken one spoke but work on both sides (i.e. loose one side by half a turn, tighten the other by half a turn) and include the neighboring spokes as well. Be aware of spoke wind-up and account for it (easier with bladed spokes). Stress relieve early.
On my first wheel some nipples broke prematurely. I suspect that turning them countless times abraded and damaged them. Now I always use grease on the nipples (where they contact the rim) and try to get it done in as little turns as possible.


Power Output at different Air Densities Factors Influencing Air Density are: Altitude, Air Temperature, Air Humidity and Barometric Pressure. Calculator: http://barani.biz/apps/air-density/

How does riding at different air densities affect Power Output and Speed?

The following chart can be found in an interesting article on Training Peaks blog.
From this you should be able to adjust your power level occordingly.


How to clean my full suspension bike I have a full suspension canyon neuron and after each wash, I'm finding that just water doesn't cut it. Does anyone know of any good products to use when cleaning my bike? e.g Mucoff.

If  I want to get it "Concours d'elegance" clean, I use dish washing detergent.

Unlike a car, a bicycle has no issue with stripping off the wax polish that protects the paint work (I don't know anyone that polishes their bike), and the dirt is mostly muddy organic materials that needs a mild soap/detergent. (Spots of oil from a over oiled chain or hub are dealt with using a concentrated dish wash liquid/water solution).

Main thing to do is keep any contamination off the disk brakes, hence the need for plain cleaners. You can go to the bike shop and buy bike specific cleaners in small, bike wash sized bottles, but I prefer to buy a gallon of basic cleaner and spend the change on things that matter, like a good coffee :)

Cleaning to me means removing the grindy stuff from around the moving bits and lubrication of the moving bits. Normally my only focus for "Shiny clean" is the shock and fork stanchions, after all, its a mountain bike -a bit of dirt gives you street cred and makes the bike legitimate...


What to put after taking off rear stabilisers from child bicyle? I removed rear stabilisers from my 9y old daughter's bike a while ago, but I lost the little pieces that are supposed to replace the stabilisers.

Today I don't even remember what they look like. Any idea what these pieces are, meaning their name & specs (if they're standard) so I can maybe order them on Amazon?

You want a washer and a nut on each side. Take it down to your local bike shop or hardware store to find the right size.  Any other parts that were on there were specifically on there for the stabilizers (training wheels).  Training wheels usually have a retaining mechanism that stops them from twisting, but this piece isn't needed once you remove the training wheels.


Differential foot stress? I'm having some pain issues (won't get specific, I know not to let the Internet diagnose me) in one foot but not the other. What kinds of motions on a bike stress one foot more than the other?

So far I've thought of

the Sheldon Brown technique for mounting a bike (one foot stomps the pedal, the other pushes off from the ground)
coasting, where I have a habit of always leaving the same foot at full extension (and carrying more weight)

Anything else I've missed? I'm consciously changing my coasting posture, and trying to train myself to Sheldon-Brown-mount with opposite feet. If there's anything else I could be doing, it would be good to know.

Perfect pedaling is actually on the rare side and generally takes a lot of work to develop.  That being said many people pedal in an unbalanced way (I tend to have a much stronger downstroke on my right and upstroke on my left).  I use clipless however, so my feet are always in the proper position (for me).  If your foot position varies or isn't correct (for you) you may experience uneven pain.  It's also possible you have an unbalanced stroke.  Either of these could contribute to single sided pain.


Bicycle lights- Indicating in the dark I am a product designer and am currently working on a bicycle lighting project and would really appreciate your valuable feedback.

In England, turning left on a bicycle is not really a problem as you would just follow the road, but turning right can be an issue as often you would have to change lanes or cut across traffic. Likewise in other parts of the world where you drive on the right, turning left would be the issue. That is why it is so important to use hand signals, so motorists can see your intentions. But how can motorists see your hand signals in the dark?

I have an idea for a bicycle light which would clip onto the sleeve of your clothing; very much like the way an ipod shuffle would clip onto clothes. It would always be on; therefore acting as a safety light as well. If you wanted to turn right, you could put your arm out and then motorists could see your intentions through the flashing light.

Many people have tried to crack the cycling indication market before, but it involves adding expensive and ugly lights to your bike. What if there was something as easy as the above, that just clips onto your sleeve- no need for bike modifications and probably less than a £10 spend.

This in mind, any answers to the following questions would be great:

Do you find it difficult to indicate in the dark? Do you think an idea like this would improve bicycle safety? Would this be something that you would buy?

It's not clear from your question whether you ride regularly a bike, but really the best way to understand the requirements for a product like this is to get on a bike and do a bunch of riding around at night.

When you do this you'll find that the visibility of signalling at night is not as big a problem as all that. First, the proper approach to making a manoeuvre is look–signal–look–move: that is, you always check that it's safe to move and never presume that anyone has seen your signal. Second, bicycle position within the carriageway is a clear signal to other road users of your intentions: if you are positioned towards the left side of the carriageway, you intend to go straight on or left, and if you are positioned towards the right side of the carriageway then you intend to turn right. (Assuming drive-on-the-left as in the UK.)

Nonetheless, there might well be people who would like to buy lights to improve the visibility of their signals, so I'll make a couple more comments:

A device that clips on to clothing depends on you wearing long sleeves and so will not be usable in the summer.
If you're going to wear a light on your wrist for signalling then the light ought to be visible from all directions (so that it does not matter which way you put it on or how you hold your arm while signalling). The best shape would be a bracelet with lights all around.

So if I needed a device like this, I'd buy a SlapLit LED bracelet.


Is there anything wrong with fat blobby frame welds? Are fat blobby welds inferior, other than aesthetically?

Here's three examples, one's a BSO, one's a decent/good Trek and one's an expensive Felt downhill full-suspension bike.

Assuming good penetration, a “thick” weld also functions as a fillet reinforcing the joinder.  The “swirly” look is OK as long as the welding puddle is continuous.  In many instances a “stitch weld” is more fatigue resistant than a continuous bead by limiting stress risers in the weld.


top tube adapter for hitch mount carrier I recently bought a Trek Navigator 1. I just installed a hitch and a Allen 2 bike rack. BUT the Trek has a verry angled top tube. so the front tire is only a couple of inches off the ground. Would a Yakima or other brand tube adapter work on the Trek? Which is stronger or rather snugger fitting?  Thanks in advance

Yakima and Thule and probably most other rack companies have top tube adapters. They all recognize the need to accommodate the sloping top tube/y frame/children's bike market. They will all function relatively the same. Unless you have an ultra lightweight delicate carbon frame/seatpost, which I don't believe your bicycle qualifies for that, you should be fine.

Most of them are adjustable so you can make them fit snugly and securely.


Hylix carbon fork and compression plug I have an Origin8 compression plug 90mm long with recommended torque of 8Nm. But it can't be inserted fully into the Hylix carbon fork I bought online as there's lots of epoxy blocking the tube in the last 10mm of space the plug requires to be fully inserted (given the length to which the steerer has been cut, ~7 inches, 17.5cm). The obstruction extends up to about 9cm above the fork crown. Rather than try to drill some of that stuff out, I bought a slightly shorter plug that is only 81mm in length.
The recommended torque for the 81mm plug is 10Nm (per the manufacturer's website).  I can't find any technical info on Hylix, so I'm wondering if 10Nm is OK, as it is a good deal higher than recommended torque on the Origin8.
The Whisky compression plug instructions say to tighten their plug to only 1.6Nm, so clearly there must be quite a difference in the design of these plugs, or quite a wide range of opinion on the proper torque, or that number is a typo.
Is there any way the consumer can make fact-based judgments on such things? Is the thickness of the steerer tube wall the determining factor? It is 2.65mm

“People often make the mistake of thinking that the plug is solely to
preload the headset bearings,” he [Raoul Luescher of Luescher Teknik in Melbourne, Australia] said. “However, due to most carbon
steerers not having much in the way of hoop strength, due to the
difficulty in laying down 90-degree fibers in a production environment
with the process used, the plug is important to contain the hoop loads
from the stem clamp. Thus I do not recommend ultralight or poorly
designed or installed plugs in most steerer tubes as we see lots of
cases of delamination caused by the stem clamp.”

https://cyclingtips.com/2017/05/cane-creek-eenut-review/

Some things to consider:

The plugs only purpose is to be strong enough to not move up when you tighten the headset down.
The steerer will be clamped by the stem, so the stem will reinforce the steerer once clamped.
The top cap recommended torque is probably 4-6Nm.
Support the top of the steerer from crushing. Although it is often recomended to add a 5mm spacer ontop of the stem so the top of the stem in not flush with the top of the steerer to help with this.

So my advice if you're worried about the steerer's integrity would be tighten the plug to a lower spec than you think and try it with the top cap, only tighten the plug further if the top cap pulls it up.
As the stem will clamp the steerer with more force than the plug expands with, you shouldn't worry about the plug damaging your steerer as you ride.
So, torque specs are in general only advisory in the sense that they will a min and max value. If you're careful and mindful of what you're doing, you don't need to look at the plug torque at all, just tighen enough so it doesn't ride up, making sure at no point you pass a damaging amount of torque (more than 10-13Nm in this case).


Chainring and chain compatibility for Suntour chainring just ordered a new chainring for my nexus-8 equipped longtail bike,
it's a suntour 48 tooth chainring shown here:
https://www.srsuntour.com/products/32-tooth-chainring?variant=27528743299

it's a 104mm 4 bolt chainring.

however I can't find specs for it anywhere - wondering if I can order a 3/32" chain (my rear sprocket spec says it works with either 1/8" or 3/32").

another thing to consider - the chain will be long (joining two chains together) as this is a longtail bike.

will the KMC Z1 (3/32") chain fit? can you recommend another?

thanks!

Apparently Suntour only makes/sells derailleur cranks. So I’d guess the narrower 3/32" single speed chain should fit.


Can a thicker chain cause it to slide/jump under pressure? I recently changed my chain on my roadbike. It's a roadbike made to a single speed.

Anyways, the new chain is a bit thicker than normal. I applied the same number of chain links to the new chain. After switching the chain, the chain jumps/slides under pressure. A problem I had before because the chain wasn't tight enough.

This time i can't figure out why the chain jumps. It looks tight enough. Could it be the width of the chain?

No. Most common chains are 1\8 (single speeds) and 2/32 for your average multispeed chain. Of course 8 and 9 speed chains can be thinner.  It may be your sprocket. You didn't state how many miles is on the bike in it's current setup. If the rear sprocket is worn, chain will skip.

Also if the chain alignment is too far off, it will skip or come off. A single speed set up puts more load on a chain without a derailleur to dampen some of it and hold it in place.

A bent chainring on a crank can possibly throw it off or cause similar problems.

If you just shortened your chain and pieced it back together by driving the pin back between the links versus using a or the masterlink, that point can be too tight and inflexable depending on how far the pin was pushed in. It can be microns of a difference and that link won't flex.


Why is a damaged bike tyre a problem? I have seen / heard of cases where bike tyres get damaged (like for example riding on a flat).  But what I don't fully understand is why the damage becomes a problem or whether the tyre actually needs replacing after being damaged or not.
Can someone explain the full consequences of a damaged tyre and whether it should be replaced or not?

Two things could happen:

You pump up the tube, and after a while, the side of the tire yields. Usually when you´re sitting on the bike, because that increases the pressure a bit more. Looks like it has the plague or something, develops a well visible bulb. The bulb grows, and after a few moments or minutes poof (or bang if it´s a racing tire at 8 bars) you´re out of air. Can happen at a dangerous moment. Usually you hear a funny sound of the bulb touching your frame before and have time to slow down.

You brake, and the side of the tire disintegrates under the sudden stress. Perhaps more likely with lower pressure (otherwise (1) occurs before). Complete loss of control if it´s the front wheel.

Both of these only happen when the carcass of the tire is damaged, due to riding on a flat (likely invisible), a maladjusted brake pad, or something else that has been making quite some noise while rubbing off the rubber down to the carcass.
Visible cracks in the rubber can grow for many years before the reinforcing fabric below is destroyed. If you bend the tire, and pieces fall off, yes, then it´s had it. The crack growth is sped up a lot by riding (or even letting the bike stand in a dry shed) with too low pressure. Rubber that is bent + ozone from the air = environmental stress cracking.


How often should I charge my (lithium) e-bike battery? I had a retrofitted e-bike running a Leed e-bike kit for 4 years. After 800 charge cycles the battery was toast. However this system is quite basic with both the battery management & charger.

I have replaced that bike with an e-bike running Shimano STEPS e8000. This has more sophisticated battery management (I believe it doesn't use the bottom 20% or top 20% of the battery to extend life) & a more advanced charger.

However I want to make sure I get as much out of the battery as possible. On most days I ride <10km which hardly uses any of the battery capacity.

The batteries on my old & new bikes are lithium-ion.

I've come across two theories for improving battery longevity:

Charge every day - that the depth of the charge effects battery health more than the frequency of the charge. So frequent shallow charges is best for the battery.
Charge infrequently when the battery reaches a certain level (say 50%). So lowering the number of charge cycles is best for the battery.

I am really curious to know which of these approaches (or another approach) is the best to extend the life of the battery.

Thank you in advance.

I presume Lithium Batteries.

TL;DNR - Charge them as often as convenient for you, always making sure you have more than enough to the next ride.

Battery chemistry makes a big difference - Older lead acid requirements are complex and there is a lot of mis-information and FUD on the internet, some spread by people who don't know what they are discussing, and some by those that do know and stand to make a profit from it. Why am I mentioning Lead Acid - because much information regarding lead acid is incorrectly used when discussing Lithium technology, just adding to the confusion and confusion means profits selling people things they do not need

Lithium - Lithium actually last best if left partly charged - not flat, not full charged, but the difference is not practically significant.  Therefore when deciding if you should charge the battery the question is about what suits you.

Lithiums are very sensitive to over charging and over discharge - so much so, humans cannot be relied on to do the job. The chargers are designed to so that they will not overcharge your battery, and the bicycle so it  will not over discharge the battery. Despite what some say, you do not need to disconnect the charger as soon as the battery is charged (although its best to turn the charger off to save power, and disconnect the battery from the charger to stop it going flat), and you can ride the bike till the engine stop working.

Worrying when to charge you battery is like worrying about when to fill up you car with gas because driving with more gas in the tank adds weight and wears out the tires quicker. In theory it matters, in practice, stopping to fill up is inconvenient and running out of gas more so, so you fill up when you need to.


How easy (or hard) is to move a Rohloff speedhub from one bicycle to another? I have two 26" bicycles and I am considering investing in a super expensive Rohloff speedhub.

I would like to know if it would be possible to easily move the wheel with the rohloff hub from one bike to another - assuming of course that both have already been set up for it (shifter, cable, and everything).

Thank you

If both bikes have a frame which is set up for it, with the long drop-out on the Thorn pictured below and the EX Box below it, then it would be the work of 5 minutes. Just unscrew (possibly by hand) that big nut on the ex-box, remove the wheel and put it onto the other bike.

The only issue to remember is to always shift to the same gear (say, the lowest) before you remove the EX-box and ensure the shifter is in that position when you reconnect, otherwise you won't be able to get into all the gears.

If, on the other hand it's a more complicated set up with a reaction arm like this:

Then it might be more complicated. Then again, perhaps the arm can be disconnected with a single pin, I haven't tried it. The two cables under the black flexible plastic cable covers will also need to be disconnected. I'm not sure how hard that is.


Derailleur play between cage and knuckle I have a Shimano 2300 rear mech that's done about 10,000m over ~7 years. Lately I've had trouble getting clean shifting and find myself constantly twiddling barrel adjusters... I'm certain the cable tension is good and (by my eye) the mech hanger is straight, but there's a certain amount of play between the cage and the body:

Will this affect the shifting much and, if so, is it repairable, or time to get a new mech?

EDIT
Closer shot of the hanger, which does look like it has a slight bend in it, now that I can zoom in this close without my long-sightedness furring things over somewhat.

How worn are the cassette and chains? How old is the shifter cable.

In my experience the order of things that cause shifting issues are chain wear, cassette wear, cables first. In my mind these are all considered consumables and replaced regularly. Derailleur hanger, especially if unknown history, is a likely suspect

Last is derailleur itself.  At 10000km on a Claris it past its 'economic life', so I would not be worried about replacing it.  The play in the video is a bit more than I would like, but I hesitate to say it is definitely the cause of your shifting issues.


Hit by a vehicle at a crosswalk This happened today in L.A. county in los angeles (just outside culver city). I was walking my bicycle down the sidewalk on the left side of the road, saw the green light and white pedestrian icon. I hopped on, and proceeded to bike down the crosswalk slowly. A man was stopped at the red light looking left for about five seconds. I assumed he was waiting since he probably saw the pedestrians behind me and the white light. He turned right without looking right and collided with me. My bike slammed against the road, and my leg twisted a bit. I had some scrapes and scratches but I didn't land on my head. I got his information and a couple of people saw it.

He apologized, and admitted that he didn't look before turning on red.

I read online that it's illegal to cycle through a crosswalk at an intersection, and that it also wasn't illegal. (so which is it?)

My bike has some damages and i want to get my foot checked out, but what is exactly is the law in this case? I was walking and then once it was green with the pedestrian icon, i hopped on and cycled.

Thanks

I don't know the specific laws in CA for riding in a crosswalk, but here in AZ (both CA and AZ are in the USA) it is actually ambiguous. While on a bicycle, you become not a pedestrian, which in AZ means that you aren't afforded the legal protections of a pedestrian, which means that in cases like yours there is no legal recourse.

However, riding a bicycle on a sidewalk here in AZ is illegal, and for good reason.

Section 275 of the CA motor vehicle code states that the crosswalk is an extension of the sidewalk, so if riding on the sidewalk is legal where you live, then you had the right of way.

After looking around, it appears that CA has a hodge podge of local ordinances pertaining to the legality of riding on the sidewalk.

Culver city ordinance §7.04.250  RIDING ON SIDEWALKS. states

  A.   No person shall ride a bicycle upon a sidewalk within any
  business district or upon the sidewalk adjacent to any public school
  building, church, recreation center or playground or upon a walkway
  specifically designated by resolution of the City Council as closed to
  all vehicular or bicycle traffic. B.   Whenever any person is riding a
  bicycle upon a sidewalk such person shall yield the right-of-way to
  any pedestrian and when overtaking and passing a pedestrian, after
  giving an audible signal, shall at all times pass to the left of such
  pedestrian.

while the ordinance for LA county, §15.76.080 Driving or riding vehicles on sidewalk. states

  A person shall not operate any bicycle or any vehicle or ride any
  animal on any sidewalk or parkway except at a permanent or temporary
  driveway or at specific locations thereon where the commissioner finds
  that such locations are suitable for, and has placed appropriate signs
  and/or markings permitting such operation or riding.

and for the City of Los Angeles SEC. 56.15.  BICYCLE RIDING – SIDEWALKS. states

  No person shall ride, operate or use a bicycle, unicycle, skateboard, cart, wagon, wheelchair, rollerskates, or any other device
  moved exclusively by human power, on a sidewalk, bikeway or boardwalk
  in a willful or wanton disregard for the safety of persons or
  property.  (Amended by Ord. No. 166,189, Eff. 10/7/90.)

  No person shall ride, operate or use a bicycle or unicycle on Ocean Front Walk between Marine Street and Via Marina within the City
  of Los Angeles, except that bicycle or unicycle riding shall be
  permitted along the bicycle path adjacent to Ocean Front Walk between
  Marine Street and Washington Boulevard. (Amended by Ord. No. 153,474,
  Eff. 4/12/80.)
  No person shall operate on a beach bicycle path, or on an area of a beach which is set aside for bicycle or unicycle use, any bicycle
  or tricycle which provides for side-by-side seating thereon or which
  has affixed thereto any attachment or appendage which protrudes from
  the side of the bicycle or tricycle and is used or designed to carry
  another person or persons thereon.
  For the purposes of this section motorized bicycles as defined by Section 406 of the California Vehicle Code shall be included within
  the terms “motor vehicle” as defined in Section 415 of the Vehicle
  Code and as used in Section 21663 of the Vehicle Code.

So it appears that it depends...


What to pay attention to when buying a used race bike What to pay attention to when buying a used race bike? - the one with thin tires :) Thanks for advice guys! I ask because I am a beginner in bikes, but I would love a faster bike. Now I have a very slow mountain bike, and mostly use it to travel from town to town.

There are lots of bikes with skinny tires that aren't necessarily racing bikes.
As with any bike, new or used, you want to make sure the bike fits you. A bike that can be made to fit with new handlebars/stem/saddle might be worth it, but that's a decision you'll need to make.
Has the bike been well-maintained? Is there rust or corrosion on the frame or parts? Is everything tight that should be tight? Do all the rotating parts turn smoothly?
Has the bike been crashed? Is the paint basically intact? Is anything bent?
Possibly harder to determine unless you're knowledgeable about bikes, but does the bike have parts that will be difficult to replace if/when that becomes necessary? Sometimes there are evolutionary dead-ends in bike technology (although I can't think of many in recent history).
Most importantly, do you enjoy riding it? It's a good idea to test-ride as many bikes as you can to get an idea of what you like and dislike.

Even if the bike isn't perfect for you as-is, it may be close enough that with some replacement parts, it'll be a good bike for you. You'll need to decide how much extra you're willing to spend to bring it up to that level.


Brake pads fall out of the caliper and stuck between the caliper and the disk At one moment the bike just stuck with this problem.

The brake pads fell out of the caliper and got stuck between the caliper and the disk.

I repaired it by detaching the wheel and getting it back inside, but now it keeps happening all the time.

How can this problem be solved? Is it adjustable or do I need to replace the pad or the disk/caliper?

Looks like cheaper model calliper - many of these use a small, strong magnet to hold the pads in place. It sits in a locating hole in the centre of the 'piston' (Whats the name for the non moving one).

Unscrew the red inboard adjuster all the way and have  a look to see if there is a magnet in place (use a screw driver to feel if its there), or a hole where one should be. They are a small cylinder about 5mm diameter by 3mm.


Advice on aero wheels I have decided to buy new wheels for this season. I'm currently riding the Bontrager Race Lite wheels that came with my bike, and now it's time to move to aero wheels to keep up. I'll do about 1300 km of racing this season (approx. 800 miles) where the longest is 540 km (approx. 335 miles), thus I will need good wheels.

I've looked at different wheel sets and considered price, quality and function. I think it has come down to these, but feel free to add anything you miss.

Zipp Firecrest 404/808
FFWD F4R/F6R
Mavic Cosmic Carbon
Mad Fiber

Although some of the wheels above is slightly too expensive, I think they are worth mentioning for the comparison.

So here are my questions:

For a good all round wheel, would you go for taller (>58mm), or lower (<40mm) rims?
Is the price difference from FFWD to Zipp or even Mad Fibre worth it in a TTT race over a long distance with an average pace of circa 35 km/h / 22 mph?
When spending this much on a set of wheels: Clincher, which I'm currently riding, or tubular?

Any advice would be appreciated, and personal experience would be highly regarded.

UPDATE: In the end, i bought Unaas CS-50.

Except for the steepest of hill climbs, aero wheels will almost always improve speed; however, the choice among race wheels will depend on the types of races you do, your strengths as a racer, how important small improvements in aerodynamic drag are to your goals, and the size of your bank account. For short individual time trials, .0025 m^2 savings in CdA (roughly, one-sixth the size of the difference between a very aerodynamic front trispoke wheel and a "standard" box rim) is worth 10 seconds in 40km and can mean the difference between standing on a podium or grinding your teeth on the long drive home. For citizen-level crit races where crashes are common, you may not want to risk expensive wheels unless your riding style is so dominant that you spend the entire race off the front and turn the crit into an ITT. For a long TTT like the Styrkeproven, aero wheels certainly won't hurt but the benefit of a deep set of rims may not be worth the cost if your team time is determined by the 10th rider to cross the line (in fact, in that case, a cheaper and potentially more effective strategy is to have everyone of the team use tight clothing and low rolling resistance tubes and tires).

Purely from an aerodynamic drag point of view, several of the larger wheel manufacturers (such as Zipp or Hed) provide information on aerodynamic drag differences (in grams of drag "force") between their various models and standard box rims. Most of these differences in grams "force" are measured at either 30 mph or 50 km/h. You'll want to convert this to the average speed you expect to maintain in your various types of races (the aero drag varies with the square of air speed) to make a rough estimate of the benefit you'll reap from switching to better rims. Exact calculations will depend on yaw angle but a handy rule of thumb is that a savings of 50 g of drag "force" at 40 km/h is roughly equivalent to a savings of 0.5 seconds/km at the same power output. Thus, the difference between a box rim and a trispoke front wheel could be around 1.5 sec/km, or about 1 minute in a 40km ITT.


converting a nine speed hybrid disc to a seven speed drop bar, is it possible? I have a used Jamis Coda Elite that I'd love to convert to a drop bar bike, but on the cheap.  I also have an older drop bar mountain bike that already has the 7 speed brifters on it.

Can I just swap out the rear cassette on the Jamis for the cassette on the MTB?  Will the rim on the older MTB have room for the disc swap?

The front tires would stay the same; just new cable to the brake for the brifters. Any help would be greatly appreciated.

The Coda's freehub body can take a 7-speed cassette with the addition of a 4.5mm conversion spacer to take up the extra room, which is a common bike shop item.

There are two stumbling blocks though.

First, if the Coda's current left shifter and front derailer come from a Shimano mountain group, which they probably do, then they won't work correctly with STI because the actuation ratio is different between mountain and road. It can be made to work badly but will never be right. So if this is what you have (as opposed to a flat bar road shifter and a road derailer), you'll need a road derailer, and then there's the question of getting one that either plays nice with the existing crank or getting a crank to match it. If you don't want to have to mess with changing cranks, you may look at the IRD Alpina FD, because it's just about the only one out there that has a cage profiled for mountain/hybrid/trekking/etc triples and takes road cable pull.

Second, you probably have normal v-brake-lever-compatible brake calipers, whereas your STIs have road/sidepull/canti cable pull. They don't work together, at all. So you need either road calipers or a cable pull conversion device such as Travel Agents.


Buying rear rack during pandemic crisis - go real bottom, up high, or wait? As you may know from my other question, I'm putting together a bike to commute. I'm big, heavy, and roads will be paved only first half of the way.
I will need to buy a rear rack for my bike. Thanks to COVID and huge amounts of people like me, who are fed up with public transport and irresponsible people in it, the middle range of racks is unavailable, and no one knows if it ever will be. Racks are light, but big and relatively delicate so shipping costs makes it unviable to order abroad. So I'm basically left with these options:

$15 rack that's cheap, relatively weak (officially 25kg, practically less), with traditional spring luggage clamp. They are made to be universal, for huge wheel range so they have obvious weak point and screws are known to be hard on the side mounted bike bags.

$50 - $60 range. Strong (officially 40kg, practically more), but with very narrow top and no way to keep any cargo that is not designed as a bike bag mountable on the rack.

I wanted $20 - $30 range rack that has wide top with spring holder and a mount that is easy on your bags, but I'd have to wait and hope they will ever appear, keep the reasonable price, and OEM market will not buy them wholesale. So that's probably not a real option.

I'm not asking which particular kind I should choose. Or rather I do, but my main focus is how one should decide which rack to choose when the middle shelf is empty?

Addendum — typical luggage

Heavy 17" laptop with charger et all
Lunch
Water and vitamin drinks
Some books or technical documentation on paper
emergency first aid kit

Things I may need to take less regularly but still often enough:

SDS Plus hammering drill
hammock, tarp and sleeping bag
Shooting range kit for blackpowder revolver, in a metal suitcase

25kg on a rear rack is already very hard to handle, especially if it’s on the top of the rack. Start leaning the bike unconsciously while standing at a red traffic light and you’ll suddenly do a very embarrassing dance trying to prevent the whole thing (+you) from toppling over. Carrying more than 25kg on a rear rack is really not a good idea. I doubt the bolts and bolt holes of the frame can survive much more. It’s also quite hard on the rear wheel, so make sure you have a sturdy rear wheel if you plan to carry this much load.
I never had a use for the spring clamp on my first rack and removed it after some time for weight savings. It’s really only useful if you quickly want to transport something small and easy to clamp, like a sweater. Even then it’s hard to keep it away from the rear wheel. I’m commuting and traveling by bike and I’m more than happy with my Ortlieb Backroller panniers (Vaude makes very similar ones). They are extremely sturdy, roomy, waterproof and quick to take on and off.
As Qwerky mentions in the comments, bungee cords are much more useful and flexible for securing things to the top of the rack. I’m actually using the detachable shoulder straps of the Ortlieb panniers for the purpose.
One more tip from experience: Tighten the rack bolts to appropriate torque and use threadlocker, they tend to come loose.


Uneven wear of brake pads Yesterday I checked my brake pads and noticed that the wear is uneven: much more on the left side, much less on the right side (both front and rear wheel).

This is how they look:

The left ones have almost reached the wear line, while the right one no.
I never noticed any problem with braking.

Is there anything I should check?

When I installed them I made sure that the distance from the rim is the same on both sides and that when I pull the brake lever they are both engaged.

With the brake tension released (either through the quick release or untensioning the brake wire) is the spring tension on both sides equal? As @Daniel R Hicks notes, some unevenness is inevitable with direct pull and cantilever brakes due to their design.

For V brakes and other direct pull (as well as cantilever) there's a little screw on each arm that helps adjust the spring tension. For cantilever brakes, you might also want to make sure your straddle cable is evenly centered.

Also, you should make sure both brake arms move smoothly by lubricating the pivots with a dry lubricant (PTFE, etc.) and working them back and forth.  There's a related question about how to overhaul the sleeve bearings: cleaning v-brake arms with riveted inner sleeve


Cross-chaining in terms of angles I'm building a recumbent trike and have reason to have the rear cassette offset from the cranks.

At the same time, the chain is very long, so the offset is compensated. It looks like the chain will be running about 3.25 degrees when the chain is on the smallest cog.

I tried to compare this with normal bike chain angles, but have a hard time finding information about chainline in terms of angles. Usually, chainline is specified in mm from the center of the bike, and there is no specific range of chain angles which is considered bad, usually there is just a vague rule of thumb not to ride cross-chained.

On a road bike with a 41cm long chainstay and 40mm wide cassette, we can use trig to calculate a max chain angle of about 2.7 degrees, if the front chainwheel is centered on the cassette. If the front chainwheel is offset 5mm from the center of the cassette, such as a cross-chain situation, then maybe chain angle is as much as 3.5 degrees. But these are approximate calculations.

Does anyone know any actual data on what chain angle is ok, except for vague warnings about cross-chaining, which depends on the bike geometry anyway?

Rear cogs on a 9-speed are about 4.5mm apart, center to center.  A typical chainstay length is a hair over 400mm.  The arctangent of 4.5/400 is about 0.65 degrees.  At such a shallow angle you can simply multiply 0.65 times the number of cogs you're spanning to come up with the angle that is spanned when you shift that number of cogs.  In other words, shifting from cog 1 to cog 9 would span 8 cogs and produce about a 0.65 x 8 = 5.2 degree change in chain angle.

Front cogs are probably a little bit farther apart, but not much.


Is it safe to go over roots at high speed on a cross-country bicyle? I have an average cross-country bike (Cube AIM), with stock parts on it.
I have no problems descending at high speeds on a rocky road/singletrack.
But when I have a long, steep descend with big roots (10cm in diameter) hidden partially in the ground, I feel like my bike is going to fall apart under me and I begin to brake more than I would like to, because I'm scared.

On such rooty (don't know if it's the right word) descend the front fork is working really hard, hitting the travel limit all the time. The chain is clanking furiously over the roots. The overall jitter is so strong that I can't sometimes keep my feet on the pedals.

Is it safe to drive on a hardtail CC bike in such conditions? If not, what kind of bike should I use for it?

It's safe as long as you use your body properly. Learn about:

proper neutral posture while descending:

light hands, heavy feet (stay above BB, mostly with your feet)
don't sit
knees bent
elbows out
back straight
look ahead (read the terrain), not on your front wheel, nor the obstacle itself for too much time

dealing with obstacles (roots, rocks etc):

choose a good line, since you are already looking ahead and not down
compress/weight before an obstacle
uncompress/unweight while hitting the obstacle

If you've never heard, thought or done any of the above before then give it a try. It'll improve your safety, confidence and handling on the bike. If you've been riding long enough not doing the above then it may be difficult to adjust. But it'll eventually happen. It needs practice and it'll not come overnight.

If you find this stuff interesting and you are really interested in improving your technique I suggest finding a skills lesson/course to take and also reading http://www.amazon.com/Mastering-Mountain-Bike-Skills-Edition-ebook/dp/B004D2BD1Q


Why do some road bikes cost more than motorbikes? Are they grossly overpriced? I have seen quite some carbon fiber bikes that cost upwards of $4000. Why do these bikes cost so much when one can get a very good motorbike for $3000?

A motorbike comes equipped with several technologically advanced systems like IC engines, electrical lighting systems, electronic fuel injection, exhaust systems etc, which require considerably more R&D to build than any bike, IMO.

What then, justifies the exorbitant price of these road bikes?

While some will say "it's just supply and demand" and companies charge "whatever the market will bear", I'm not convinced that your comparison is fair to try and determine whether bikes are overpriced relative to motorcycles. Using a $4,000+ road bike and comparing it to a $3,000 motorcycle is comparing the upper end of one product to the lower end of another.

For example - you can go to performancebike.com and buy a reasonable entry-level road bike for around $800 ($500 or less if you watch for sales). That bike will have an aluminum frame, low-end carbon fork and a hodge-podge of low-end components.

Similarly, you can buy a low-end 2013 Honda CBR 250R at a list of $4,199. That motorcycle has a relatively small engine and will likely will have heavier components.

Both of those products are consumer focused, recreational products; not high-level competition machines.

If you move to the upper end of the recreational products, you are looking at $2,800 for a full carbon with mid-level components on the bike side, versus, $14,000 for the CBR 1000 on the motorcycle side. Neither of these is anywhere near the upper-end of competition ready products.

If you look at the relative percent difference in price, it about 250% between base and mid-level models of both products. It's up to the individual consumer to decide whether the added benefit of lighter materials, better components on the bike side, and more power, better component on the motorcycle side is really worth a 250% increase in price, but that's why manufacturers release a range of models.

If you want to compare between the products, the base motorcycle is going to cost you a little over 5 times what a base bicycle will cost (not counting add-ons like insurance, gas and maintenance). The prices of the higher level motorcycle and bicycle are at about the same ratio.

Finally, I don't know anything about use of composites in motorcycles, but I think it's debatable that the technology in a motorcycle requires significantly more R&D than for a bicycle. Precision shifting, weight minimization, not to mention the fabrication of carbon frame tubes to be light, strong, and exhibit directional dependent stiffness and flexibility is R & D intensive. This Gizmodo article explains in more detail why carbon fiber products are more expensive (hat-tip to Tom77) As far as I can find there are no stock motorcycles available with carbon frames, and Ducati sold a replica Desmosedici with a carbon seat support for over $70,000.


How feasible is it to transfer modern (2010) components to a 90s frame (road bike) My 2010 aluminum frame may be toast (stripped bottom bracket) and I was considering getting an older chro-mo frame and transferring the components to it.  It's a racing/sport style with drop bars and 24 speeds.  I'm an beginner/hobbyist bike mechanic, I have the basic tools and can take a bike apart and put it back together (given enough time ;)).

If I remember correctly some time in the past road wheels were commonly 27".  When did they switch to 700mm being the common size?

(I ride for leisure and exercise about 50 miles/week.)

It is possible to make the switch, but there are a few components that probably won't be an even swap. This will depend on the vintage of the frame you're planning on using (and it really should be steel as aluminum doesn't age gracefully). Since I have a steel 1992 Bridgestone RB-T, I'll use it as an example.

The headset on your bike is most certainly 1 1/8" threadless, while the headset on an older bike will be 1" threaded. You will have to use a threaded fork and a quill stem. You may find it tricky to locate a quill stem to fit your handlebars if they have a larger clamp diameter (older bikes commonly use 25.4mm and 26.0mm bars).

Wheel size won't be an issue. 27" wheels have an ISO diameter of 630mm while 700c wheels have an ISO diameter of 622mm (4mm smaller at the rim). You'll want to make sure that your brake calipers reach the rim squarely, but that will depend on the frame. It really shouldn't be an issue unless you decide to run 650b wheels (which have many virtues).

A bigger problem may be fitting your rear wheel in the frame. Presumably your rear hub as an O.L.D. of 130mm (i.e. 130mm wide). Most older frames (such as mine) have 126mm dropout spacing to accomodate 6 or 7 speed freewheels. There are resources on re-spacing your dropouts by bending the stays (this is only possible on steel frame bikes.) Alternatively, you could buy a freewheel rear wheel, but then you'd have to futz with your indexed drivetrain and that's no fun.

You'll want to make sure that you use the bottom bracket length specified for your crankset which may require removing the old bb components from your new(old) frame. With the right tools it shouldn't be difficult.

Those few things will be your bigger obstacles. There may be one or two other small things, but they'll be easy to work around. If you're serious about this, also consider that there are a great many steel frames from the 80s that are worth the effort.


Hi what Brand is this fixed-gear bike? White frame  it looks like a road bicycle
Serial number is DJEI265384

Based on the downtube logo this is a "FIX-D" brand of fixed-gear bicycle.
These are low-spec bikes sold through Target and aliexpress.  The frame is Steel.
Someone has removed the front brake and brake lever, and the front wheel's QR lever is in a bad angle.  Can't comment on the rear of the bike.  The saddle on yours is from a Diamondback as well.
The front tyre has been changed at some time, and its possible the front wheel is different from stock too.
The left hand pedal is busted in half - that's not safe to ride and needs to be replaced.  Generally you have to buy pedals in pairs, check elsewhere on this site for how to fit and the pitfalls/gotchas.
I removed the 27-inch tag because this bike has 700c wheels, which are 622mm.

Source: https://www.propertyroom.com/l/magna-fixd-road-bike/10178232


Is this a helmet defect or not? I bought a new Giro Savant helmet online and, after unboxing, noticed that the EPS foam seemed to be quite jagged and uneven at the intersection with the dial system (see photos below).

This does not look like damage to me and the foam was probably cut that way. I have seen a few images/unboxing videos online that also seem to have quite jagged foam at the intersection, so this suggests that maybe most of the Savant helmets are like this.
I am not bothered with the cutting of the foam if it is just cosmetic but obviously I would need to know that the helmet is not compromised before I can use it.
I would really appreciate any advice so that I can determine whether the helmet is safe to use.

The jagged and uneven edges you are seeing around the straps are merely cosmetic. At best they are at the minimum tolerance for manufacturing quality and at worst are an isolated case of tolerances going wrong during production.
Either way, as long as the integrity of the foam in the helmet is not compromised (by virtue of crashing or the like), then it is safe to use. Happy riding!


Disadvantages of using QR->Thru Axle Adapters? I have a 100x15 front 142x12 rear cyclocross frame. I'm considering getting mid range wheels with quick releases that come with thru axle adapters. The wheels are lighter and better than most options in this price range that come with native thru axles.

Question is, are there any negatives for using qr->TA adapter besides weight?

The wheels in question from crc
http://www.chainreactioncycles.com/prime-race-disc-road-wheelset-2017/rp-prod142942

This is a deceptively complex question because it touches on many aspects of hub design, and answering it properly would also require taking some kind of survey of what design choices have wound up getting made for the various convertible vs. dedicated size through axle hubs, particularly in terms of what bearing sizes are used. Furthermore, for practical purposes the story is quite different for convertible road vs. mountain front hubs, because within mountain many of those hubs use bearings with a 20mm ID so they cover 20mm all the way down to QR, whereas the size variance involved with a 15mm/12mm/QR hub is much less.

But, broadly speaking, the main potential downside to convertible hubs of this style is that even if you're fine with it being as big and heavy as it needs to be to have good bearing durability, the person who designed it might not see things that way. They'll probably see it instead at some level as a trade-off that has to be made. And while usually in practice that may only make a marginal difference (I don't think I've met any convertible hubs with extraordinarily teensy bearings), the bike industry is quite good at occasionally turning out products that shave grams in unfortunate ways, on things like bearings and spokes where a little weight spent goes a long way towards durability.

Again, this applies more to fronts than rears, because the variance in axle size is so much greater. I doubt it applies to rears much at all, but determining that is where the aforementioned survey of bearing choices used across hubs would come in handy.

Some companies (I'm thinking of White with their Venti front hub, but there are others) have wisely taken the pressure off to make compromises here by making the 20mm in their lineup a dedicated design, and the others convertible. That makes even more sense now that 20 is firmly DH/FR, where there are going to be other aspects of the design you want more usage-specific, but for a while it wouldn't have been as easy a choice because before 15 came out, 20 was seeing use on trail and even XC bikes.

Another aspect is cost, particularly when there's a rear hub like the one in question involved. The endcaps and axles cumulatively make a pretty big pile of precision machined parts you're paying for but maybe only using some of. Not a huge deal, especially if you're going to actually use the convertibility, but for example with Novatec hubs like these being high quality Taiwanese stuff, you are paying something for the extra parts, and what's really going on is if you're buying a wheelset/hubset that just comes with all the conversion parts, you're paying for a manufacturer's decision to simplify things by just giving everyone everything and letting the costs tick up accordingly. (When a bike brand or wheel manufacturer orders hubs from hub manufacturers, it's entirely up to the buyer whether to get the extra conversion hardware. Hub makers most commonly wouldn't be sending all that stuff out since most of their hubs wind up OEM on bikes.)

In cases where a hub is convertible across axle standards where one reason for the new standard was to change hub geometry to create a strength increase, such as hubs that can work on both 12x142 and Boost 148, you get none of the advantages of the new standard.

Finally, it only gets harder to create effective sealing when you're designing around multiple different axle adapters that might be used. That doesn't necessarily mean sealing will be deficient, but it is at some level a downside.

To be clear, there are no major categorical downsides to hubs like this. A lot of them are out in the world performing very well. But there are subtle downsides that get incurred as a result of adding more factors to the design criteria.


How to fix folding lock holder I've got an ABUS Bordo Lite folding lock and the holder it came with which attaches to the bicycle's frame using two thin metal strips and/or two Velcro straps is now broken:

As you can see, the soft plastic strap keeping the lock securely in the "holster" tore. Although the lock itself doesn't fall out when keeping the holster open as depicted, it does rattle around a bit and, more importantly, the strap itself is incredibly annoying because it moves around and sometimes tickles my sensitive, powerful-yet-dainty high-performance calves (no, I don't shave them).

Attempted solutions

Rubber band: I had tried wrapping a rubber band around the "inside" loop on the upper part of the strap and then wrapping the rubber band around the nub (what is it called?) on the holster itself, but the rubber band becomes more and more slack with time and then itself becomes loose.
Electrical tape: I tried wrapping electrical tape around the broken loop in order to try to hold the loop together, but it couldn't withstand the stress of the loop being closed around the "nub" on the holster.
Superglue: I tried supergluing the broken loop back together by letting the glue "set" inside a wrapping of electrical tape, but it didn't hold.
Kill it with fire: Since some plastics are re-formable, I had tried melting the broken loop with a lighter and then "re-forming" it by holding it together with electrical tape until it re-set. That didn't work at all and simply made it look uglier than before.

I suggest cutting the broken loop off and using a cable ("zip") tie through the big triangular loop.  Two cable ties chained together may help it lie flatter.  As an alternative a short loop of bungee cord would also do the trick (available from camping shops).

Thats actually nicer than most lock holders, and seems worth saving.

Edit:Picture:


Trek Domane and undamped motion with Isospeed? Being a car guy and autocrosser, I'm familiar with suspension systems and the necessity to find a balanced spring/shock combination to create the best possible compliance, ride quality and performance in the suspension.

So I can't help but think that the Isospeed technology on the new Trek Domane is a little odd as it's essentially all spring and no damper.  Aren't you going to essentially have undamped motion while riding? For example, you can see the bounce in this video...

I haven't ridden one of these bikes yet, but I'm not sure if a short test ride would be enough to make a proper assessment.

And I know this isn't exactly a conventional spring.  So I suppose my question is if there's anything about Isospeed that gives it some sort of damping characteristics to minimize excessive bounce?

As you already suggest the behaviour is not that of a conventional spring. Compared to a conventional spring I would expect it to have some quite high internal damping so it may have characteristics similar to a spring/shock combination.


Have rollerbrakes a longer stopping distance than drum brakes? In my experience rollerbrakes are very weak comparing with drum brakes. Is it normal that they have a much larger stopping distance than other brakes or is it just my own bicycle?

In my experience roller brakes can be set up to lock up a front wheel, but it takes more lever force to do that than most other brakes. Many riders consider that a useful feature, but it's disconcerting if you're used to other types, which generally fall into the "lots of force and it still doesn't work" or "a bit too much force will lock the wheel"... roller brakes feel like the former but are actually the latter.

But most bike shops don't do that, and Shimano ship them from the factory requiring a very large force to lock the wheel. It's possible to adjust the brakes to require less force, if you find a bike shop that's confident working on those exact brakes. It is likely to require some asking around on your part to find that shop (realistically, the one mechanic who likes these brakes).

I'm a fairly strong guy with good grip strength and it feels as though I'm more likely to break the lever than lock up the front wheel. In reality though, actually testing this is hard because I had to sprint up to speed, then grab the brake lever as hard as I could, squeezing quickly before the bike stopped, to get the front wheel to lock.

I think that's actually a useful way for a brake to work - it's very hard to lock the front wheel even in a panic stop, because the bike normally comes to a halt before the wheel locks up. The problem is that not everyone has "big strong man" grip strength, so may find that the brake just doesn't work for them.

(full disclosure: I had one of these brakes on the rear wheel and did not like it. I wouldn't have one again if I could avoid it)