Stromer S1 bottom bracket replacement I have a soon-to-be-unusable bottom bracket on a 2016 Stromer St1.   I believe the cause is bearing failure.

I cannot find the exact replacement online (BB-7420: BC 1.37 x 24 T: Shell 73 : spindle 138.5).

Obviously the easiest option is source a replacement from Stromer but since I am not happy with the life span of the OEM I would like to upgrade if possible.  I am just not sure of my options here and I don't want to pull apart the bike until i have a solution in hand, as I commute to work on it.

Phil Wood is probably your main option for an upgrade, but at least it's a good one. They have stock options of 135 and 145 but considering the bike, I would just order a custom spindle to match what you have exactly. Pull the cranks and measure; don't assume the 138.5 is actually exactly right in this case.

You could also do measurements and potentially play the odds whether the 135 will work well enough. There are questions here about this. Note that sometimes there's an element of not knowing until you try on 1x systems when you move the front chainline in, because it can be unpredictable when issues with the chain wanting to catch when in the smaller cogs can result. Phil square taper BBs are unique in that they can be tuned for this if needed by offsetting them in the frame, but you ideally don't want to do that since it offsets the Q as well.

I don't know why they use this spindle length. My guess is the rear hub spacing is an extra wide, proprietary size. Depending on what's going on with why it's got a 138.5 square taper with proprietary cranks (or at least looks that way) in the first place, there may be some possibility of upgrading cranks as well if you wanted.


Is there a simple way to measure, record, and use wind resistance or tail winds? Since moving to a new office where my commute is a bit longer I have been obsessively recording my cycle to work hoping to see a gradual improvement. (N.B. I've stored them on Strava but you need to be a member to see aught but a summary page). It looks like any increasing fitness is not the dominant factor, wind is. We know that wind resistance has an enormous effect but is there a way to factor it in to my data? How might I measure, record, or just note wind speed through my ride and somehow factor it out when calculating performance each day?

Arguably, just the time it takes you to get from point A to point B is a perfectly good measurement of improvement (same with average speed)

As you say, wind influences this, as does countless other factors - traffic lights, weather (wind, wet roads, snow and ice, etc..)

However, unless you are remarkably lucky or remarkably unlucky, these variables will largely average out over time.. E.g a head wind on the way will become a tail wind on the return journey (or a windy day followed by a calm day, or the prevailing winds changing throughout the year)

It's also worth remembering that elapsed time wont just be skewed by negative factors, but also positive things like your bike-handling skills, confidence cornering, confidence at drafting other vehicles etc

The main point is: You should not judge fitness improvement based on specific rides ("todays ride took 2 minutes longer than yesterday") but instead look at trends over time. For example, here is a plot of average speeds for all rides during my first year of "proper" cycling:

Day-to-day it was impossible to see any improvement in speed, it was hugely influenced by factors like the terrain - but, over time there is a clear trend.
Speed and time alone aren't a good indication of fitness

Power output as measured by a device like a Quarq, PowerTap or SRM power meter is far more representative.

Aside from being prone to external influences, increases in speed become exponentially harder. Going from 10km/h avg to 20km/h is far easier than going from 20km/h avg to 30km/h (and then 30 to 40 is even harder)

Part of this is because air resistance approximately increases with the cube of your speed ((ground speed)*(air speed)^2) - in other words, air resistance increases exponentially compared to your speed

I would speculate that the other part is, increasing your power-output becomes exponentially harder the closer your are to your "genetic limit" (e.g increasing your 1-hour sustained power from 100w to 200w is much easier than from 200w to 300w, increasing from 300w to 400w requires far more training)

What does all that rambling nonsense about watts and exponents mean?

If you look at my average-speed plot, there's a large increase in average over the first few months (the easy 10km/h->20km/h increase), then the speed appears to plateau, despite the fact I was increasing in fitness over that time...

This is where power meters become especially useful: It more directly measures a useful metric of fitness, essentially how hard you can pedals for a given duration.

I bought a power meter near the beginning of Dec 2012, where the avg-speed line is quite flat. I knew I increased in fitness since then, however the average speed line doesn't really reflect this.

The best-efforts power curve far better reflects my improvement than avg-speed:

As you can see, despite no large increase in avg speed, my best effort 1-hour power increased from 197w to 254w, which is a substantial change (dividing by 60kg and using the easy-to-misinterpret "watts per kg chart", it's an increase from "moderate" to "very good")

Power meters produce great measurements, but, they are expensive.
There are ways to measure wind speed on a bike, but not for the reasons you describe

iBike sell several versions of a bike computer which measures wind speed.

It's sold for two reasons, the first is to estimate power output without a power meter (the iBike Newton is quite expensive, but cheaper than a direct-force power meter like Quarq, PowerTap etc)

The second reason is if you have a power meter, it can use the power output, ground speed and wind speed to estimate your aerodynamic drag (since your speed on flat terrain is primarily based on power output divided by aerodynamic drag)


TdF: How does putting one team member in a break away help the rest of the team? In a race such as Le Tour De France, what advantage does a team gain from sending one team member into a break away? What does the rest of the team, including their favoured rider, gain?

The full answer depends exactly on the teams involved and the composition of the break but, in general, the key to understanding this isn't physics as much as it is game theory.

In a race like the TdF, there are many separate competitions being run simultaneously: not just for the overall General Classification but also for stage wins, the (green) points jersey, the (polka dot) mountain jersey, the (highest ranked rider under age 25) white jersey, the team with the lowest cumulative time, and so on. Not every team has a GC hopeful, but every team has a goal or goals. If your goal is a stage win, or to get one of your riders a particular jersey, getting someone into the break can allow the rest of the team to shelter in the peloton, conserve their effort for the entire day, and prepare for the next day's stage.

A more complicated case is when you do have a GC contender and also someone in the break. Depending on the composition of the break, your break rider can be threatening some other team's goal of a jersey. In that situation, you're playing a waiting game (a game of "chicken"), to force the threatened team to chase the break, while your team shelters in the peloton, conserving their effort for the entire day.

Sometimes a GC-contending team will put a rider in an early break with a set plan to drop the rider out of the break later in the race to help the team's leader. It's like caching supplies farther up the road that they can draw upon if needed.

Sometimes you have a GC contender but no one in the break, and the break composition threatens the secondary goal of another team. If so, you can wait until the other team starts to panic and initiates the chase, then shelter in the peloton, conserving your effort.

Teams will always look at the riders of an early break to determine whether its composition fits their goals. If not, the team will chase early to absorb the break, then wait until a different, more acceptable, break forms; in which case they will allow the break to continue while they shelter in the peloton and wait for someone else to panic and initiate a chase.

As the stages count down in one of the Grand Tours (the Tour de France, the Giro d'Italia, or the Vuelta a Espana), teams that still haven't yet won a stage become more and more desperate to get someone into an early break. There can be several re-shufflings of break compositions as the directeur sportifs try to get at least one rider into a stable break. That can be miserable for already tired riders as they accelerate again and again to claw back unsuitable breaks.

There are 20 teams on the road simultaneously each with different goals and skill sets, with many different sub-competitions. In terms of n-person game theory, cycling allows (encourages) temporary coalitions, collusion (as when members of different teams in a break work together to stay away), side payments (not only of money but also of agreements not to contest a sprint or mountain point), prisoner dilemmas, bluffs, feints, and tops it off with reneging. Then they have to do it again the next day, remembering whether a particular team carries through with its promises. This is the reason why mass start bicycle racing is, from both a strategic and tactical perspective, so much more complex than sports that feature only two teams facing each other on a field.


Annoying clicking sound from the bottom bracket I just purchased a Fuji ACR 2.0 road bike from a guy who bought it three months back but didn't ride it at all. I brought it home and found that it is making a clicking sound when I pedal. The sound is coming from the bottom bracket. Please check the video for more details:

Should I worry much about it? I'm from Bangladesh and there isn't any specialized shop where I can take it to be inspected. I have to do the fix myself. So before I jump in to open up the bottom bracket, I wanted to get advice whether I should ignore it and ride it for few days hoping that noise will go away...

Video including full drive train:

Is it happening only when you pedal backwards or forwards too?

I note you have a small spoke guard on the back wheel.  Take a close look at that.  It might be cracked and when you back pedal the freewheel teeth might be catching on it.  It seems way to loud and plastic like to be a crank issue but then again I'm not there.  All my crank issues have had a much more solid clunk sound and were not nearly as loud.


Trying to find a FC-M371 crank on line but no luck for my part of the world (Australia, New Zealand, Pacific Islands) I need a Shimano FC-M371 crank set for my 29 inch Avanti mountain bike. Crank arm 175mm, 44 teeth on large sprocket, 32 on medium, then 22 for small.
Having trouble location one in my part of the world. Is there an alternative compatible crankset that would fit that anyone knows about?  Or a reliable online supplier that I can get one shipped in from?  Thank you.

That is a standard square taper BB, so an square taper BB with suitable sized chain rings will replace it.  While 9 speed would be ideal, if the best chainring match you can find is 8speed it will work reasonably well.
As far as chain ring sizes, you do not need to stick with 44/32/22.  If you go larger than 44, you might need to lengthen the chain. If you increase the difference between the 44 and 22 (22), you may have problems getting it to work well.
A suitable low cost replacement might be FC-M311, which is commonly 22/32/42 - a slightly lower top gear.
Without offering recommendations, Wiggle and Chain Reaction in the UK happily supply into NZ (as long as its not Shimano) , along with JensonUSA in the US. You LBS will be able to source a suitable replacement very easily, and unless you have access to a crank puller, probably cheaper to get them to install it.


Trigger Shift equivalent to SRAM MRX 21 speed on Btwin Rockrider 5.0 I've a Btwin Rockrider 5.0 which comes with SRAM MRX Twist Shifters (21 spd 3x7). But lately they have been giving me problems in shifting, I've had bad experience with twist shifters earlier also( Shimano Revo), thus I want to change the shifters to trigger shift. Can anyone suggest which one's are compatible with SRAM MRX (21 spd 3x7) shifters.

The MRX twist shifters are 3x7 Shimano-compatible shifters, so you can use any 3x7 Shimano shifter set from the mountain-type group.

Unfortunately, the only trigger shifters which are 3x7 Shimano compatible still made are from the Tourney line, such as the Shimano Tourney ST-EF40, which are of rather low quality. You may be able to find an old Shimano Acera or Alivio or Altus 3x7 shifter set if you look on Ebay or something.

I had a 3x7 drivetrain on my commuter, and ended up swapping the rear freewheel (yes, freewheel and not a cassette) with a 8 speed freewheel, and getting some Shimano Alivio 3x8 shifters which were easy enough to find and of good quality. I wasn't able to get the Tourney shifters to give good shifting performance, and I don't like twist shifters (for the 3x7 drive trains, I suspect SRAM's Shimano-compatible twist shifters are the best of the indexed shifters which are still on the market in terms of reliability; they're all cheap pieces of junk these days).

Another alternative is to use a friction shifter. Very cheap to buy, though you just have to get used to shifting into the right position by feel. This is what I'd likely have done if I didn't upgrade to 8 speed.


Do I have to simply wait for google maps to add cycling directions to my area? Or can I help? Related to this question about submitting road data to google maps. I'm curious to know if there is any way to get Google started on cycling data in my city. There are a lot of cyclists in my city, but as it is located outside of the US, it will probably take some time before cycling directions show up on Google Maps.

It does seem to be possible to use the "report a problem" feature of maps to add new route data.  But what can I do if there is no cycling data to begin with?

Have a look at http://www.opencyclemap.org/ it uses the http://www.openstreetmap.org/ data, so you can help them by mapping your local cycle ways.


Why does my back wheel keep becoming untrue? So I broke a spoke a week ago, and when I put a new spoke in you know I trued it. Now, a week later, the bike feels like a kayak, because the back wheel is not very straight. Any idea why this would happen?

Some other information:

Hybrid road/mountain bike, single speed. Pretty tall, like a 62cm frame I think, with relatively small wheels.
I rode the bike with a broken spoke for another 30 miles or so before I had a chance to do something about it.
I wheel got so out of whack with my broken spoke that it caused trouble with the rear brake: if I jammed the rear brake, the brake pad would slip off the wheel.
Everything was fine up until the past few days

It's still rideable, and when I have a moment I'm going to go to the shop and true it again (hey, bikerowave!), but it seems like a waste of time to do that if there's some essential problem I'm ignoring.

I strongly suspect your spoke tension is quite uneven. If you installed the new spoke by just adding the new spoke, then that's even more likely.

A wheel with uneven tension will do exactly what you describe. There should be only two different spoke tensions in a rear wheel - the tight side and the loose side. Wheelbuilders will keep working a wheel until they get +/- 10% or so. Smaller range on a new wheel, wider on a cheap and/or old one (wheelbuilders rarely build cheap new wheels, those are made by machines). If you don't have a tensiometer (Park tool one, ~$60) you can possibly do it by the pitch of the spokes but I've had little luck with this - it's more affected by where the spokes cross each other than by spoke tension (ymmv, I have perfect pitch and am in other ways fussy, plus I have access to a tensiometer).

The problem with older wheels is often just getting the nipples to move on the spokes. That can take lube and time. Often more time than the cost of a new wheel. But if it's your time, that's "free". Again, use a grease-based chain lube (or for once, WD-40 or similar) on the spoke/nipple junction and also the rim/nipple area. Then work each spoke gently (less than half a turn) until the spoke moves on the nipple. Realistically, gently is an exaggeration - you don't have a lot to lose by breaking the spoke doing this, except that breakage normally happens on marginal wheels (cheap and broken), so you run the risk of breaking enough to make the wheel uneconomic to repair even if you're only paying for new spokes not labour.

I think your best bet now is to make sure as many nipples are free as possible, then take it to a bike shop. It'll cost $30-$100 to fix, but most shops will let you say "spend $X on it, then call me".

At some point the wheel is so warped and unreliable that you just need to buy a new one. I think you're 90% there right now. It depends on how much you're a gambler... you might spend $30 and get the wheel nicely trued and solve your problem. Or you might spend (say) $50, get the call and they say "it's definitely broken now" and you have to buy a new wheel.

If you're short on money another second hand wheel might work, and it'll definitely be cheaper than a new one. Check your local tip shop/ bicycle recycler for cheap ones.

edit: tensiometers are standard bike shop tools, the cheap Park ones work pretty well and are only about $US60 online. The more expensive ones don't work a huge amount better but cost a lot more ($US300+). I've compared a DT Swiss micrometer-based tool to a Park one and no-one in the shop could reliably measure more accurately with the DT one. It was harder to use and heavier so we went back to the cheap one.


Correct spoke tension for DT Swiss EX 471 26" 32h rim paired with Wheelsmith DB 14 spokes I am currently in the process of building a wheel, and I'm super confused on how to determine the correct spoke tension.

I bought the Park Tool TM-1 to correctly gauge the tension.

DT Swiss doesn't provide the recommended spoke tension for their rims; I triple checked the manual and couldn't find anything for a DT Swiss EX 471 26" 32h rim. This forum says I should shoot for 123kgf... but I don't know how reliable that is....

I'm also confused about my spokes. I went with the Wheelsmith DB 14 spokes (260mm); apparently these spokes get wider at both ends (2.0mm) and in the middle they are (1.7mm)...

When I go to the Park Tool Wheel Tension App, it asks me for the "thickness" of my spokes.

Two questions:

Should I enter 1.7mm or 2.0mm into "thickness" on the Park Tool Wheel Tension App
What should my tension be for the DT Swiss Ex 471 rim?

I believe DT has a blanket recommendation of 1200Nm for all their rims, or 122 kg-f. You could email them to corroborate but that number should be safe.

Use the tensiometer chart for the thin section of your spokes. By the same token, always position the tensiometer such that you're isolating a thin segment for measurement. If you had any of the thick section in there, the spoke would deflect differently and the measurement would be useless. Wheelsmith spokes have long butted sections with very short transitions, which makes it easy. DT spokes are the opposite, making tensiometer position fiddly at times.


Do I need a Blackburn bike rack for my CoPilot Limo kids seat, or will the vintage Schwinn rack do? I was given a CoPilot kids bike seat and the instructions say that it requires a Blackburn EX-1 rack. But will my Schwinn bike rack do the trick, safely?

According to the user manual, the Blackburn rack is required. The seat snaps in to the rack, so the old Schwinn rack won't work.


How to remove a Joytech freehub (5mm allen key version) I've been trying to remove broken my joytech freehub (from an 11 speed felt b16) for a frustratingly long time.  The model in question takes two 5mm allen keys, and is not the same as the seemingly more common one, which takes an 11mm allen key to remove, like these  here and here

I have successfully removed what look to be seals from each side, but I am now stuck with two holes which receive a 5mm allen key, but that will not budge, to the point i'm concerned that maybe they're reverse threaded and don't want to apply too much force.

Here are two pictures of the drive side:

and the back side:

As i say, both sides take 5mm allen keys. Can anyone shed any light on how to remove this type of hub?

To answer the question, I had to give a sturdy tap to the axel from the back-side (though it looks like you could have gone from either end), which then popped out (leaving me able to remove the bearings) and left (what looks like) the 11mm allen key space to remove the freehub.

Update: you actually need a 12mm allen key (no need for the 11mm at all). You need to use the long part of the allen key (preferable keeping the short end in a vice) to loosen the larger interior receptor (12mm as opposed to 11mm, which is accessible from the drive side)


How fast do you need to be going to get an effective slipstream on a bike? How fast do you need to be going to get an effective slipstream on a bike?

It depends.  I don't know of any scientific research to support an actual speed.
The main factors are the speed of the wind that you are riding in, and the size of your shield (i.e. the bunny in front who is giving you the wind break - the bigger the better) and how closely you follow.  In still conditions I find that even at about 24km/hr (15mph) I will notice after half an hour or so that I have not worked as hard had I been riding out the front.
If there is a raging head wind then virtually any speed will find you having a noticeable advantage in the slipstream.  Just try being out for a while at the same speed and you will feel the difference in your heart rate and muscle output.
The size of your shield also helps.  Being in a large bunch effectively increases the size of the shield, though it is not a linear increase, but rather a diminishing one. That is, as you go from say two riders to 5 riders you get a fair increase in advantage , but going to 10 riders only gives you a small increase in advantage over 5 riders.  The third factor of distance is not as important I feel, provider you are within one to two feet and are not going at top racing speeds. As you go faster the distance at which you get an advantage increases.  Of course the maximum advantage is obtained when you are within millimetres of the wheel in front, which is why track racers ride so close, but then you increase you risk to touching wheels and having a crash.


Rim compression after tire inflation I trued my wheel yesterday a bit, since many spokes lost some tension. Once I finished, all spokes were quite rigid.

Then I put the new tire on and as I was inflating it, I heard the spokes loosen up, with a typical cling, as heard while truing. The tension adjustment seems to have gone.

The tire was indeed hard to put on, but after inflation it fits the rim properly, no part of the tire is sunk inside. The pressure is also correct, 0.4 MPa (the max pressure allowed being 0.45 MPa).

In theory, the inner tube expands equally strong in all directions, so also inwards; however I have not observed visible contraction of the rim so far, even in the cheap $15 models.

Maybe a wheel should be trued with the tire on?

The sounds you heard were the spokes unwinding as the pressure in the tire relieved some of the tension in the rim. As you tighten the spoke nipples the spokes tend to "wind up" due to the friction between the threads in the nipple and the threads of the spoke. If the friction is high enough (old corroded spokes/nipples or a lack of lubrication on the spoke threads) you're just winding up the spoke.

As you true a wheel, pay attention to the spokes – are they moving with the nipple, or are you actually able to tighten the nipple on the spoke. One place where you can easily see this is by watching the "back" of the nipple on the inside of the rim. Add some light oil if necessary to help lubricate the threads. Expect some wind up, it is pretty much unavoidable. To release the wound up spokes you can put the wheel down on a hard surface and press down gently on the rim. Work your way around the wheel pressing down on the rim – you should hear the spokes unwinding and perhaps feel them moving as well. Do it on both sides of the wheel.

That should go a long way towards resolving the problem. For what it is worth I never true new wheels with the tire on.


When starting to pedal, it takes half a rotation to "catch" While power pedaling on my mountain bike, when I coast for a second, it takes a half a circle on my crank to catch. Can anyone tell me the problem?

If chain us not slipping then id say you have a busted freehub by the sound of it.

Take the cassette off, remove the freehub inspect the paws check for excess grease or lack of.

Otherwise look at a new freehub body. I had the same issue you describe last week.


Are most bikes' paint jobs not as durable as they used to be? I am asking specifics in a few posts so as to not get into discussions.
Consider this a continuation of bike quality for the price.
I find the paint job on my bike to be nice but very thin and fragile.
It scratches very easily. When I was a kid you would need to use a
jack-knife to scratch the paint. I know there is the rationale that paint weighs and so to eliminate weight they spray the paint on as thinly
as possible. Even the rubbery plastic of my U-lock scuffs it.

Price.  A combo undercoat/primer, a top coat, and a lacquer/transparent would be the norm.

In the 80s, a nice bike might have had 10 very thin spray coats with multiple clear coats on top, most of which were over the decals/transfers.  This represents a lot more work, time, and materials.

In addition, the older bikes would have been steel, whereas the newer bikes are possibly aluminium now which doesn't hold paint as well, due to microscopic differences in how the paint keys into the surface.


Using normal square bottom bracket on crankset designed for E type? I am building a LHT 26" and I am planning to use a square taper bottom bracket. Also want to have triple chainring with a small chainring 22T so bought the Shimano Alivio FC-M430, about the best crankset Shimano lets me buy these days for square taper and these settings. But I have realized this crankset is supposed to be used with an E type BB. I really don´t want to use this type of FD so my question is: Can I still buy a ´normal´non E type of BB (say UN55 113mm) for this crankset? Will the chainline be badly affected? Will I have to add spacers?
Many many thanks in advance!

Cranks are never e-type specific. Some frames dictate you use an e-type FD and BB. You're free to use whatever normal square taper BB.


Remove old non-indexed levers for gear changing to make "fixed" speed bike? I recently got an old bicycle for the sole purpose of using it on a trainer. It has old non-indexed levers for gear changing and they don't seem to work OK. The front one slips into lower after a while, and the rear one is now "locked" since it's plastic, I don't want to force it and break it.

I don't want to invest much into this bike, it was already more than I was planning to spend on it.

I was thinking to remove them and fix the derailleurs on a specific gear ratio. I would like to be able to adjust the rear one, but wouldn't mind if the process is somewhat cumbersome (ie: requires tools).

Is this possible? What would be the best path to do it?

Some pictures for clarification:

Shifters:

Front derailleur:

Rear derailleur:

There doesn't seem to be any barrel adjuster on the derailleur side, just on the shifters.

If I understand correctly you have slipping shifting levers that let the derailleurs move without your intervening. A non-indexed shifter slips because the friction setting is too low.

Friction of the lever is easily adjusted by a screw at the side of the lever. If it still slips after tightening you'll unscrew the thing taking care to remember the correct order of items when is comes apart. (Take a photo maybe to assist your memory.) Then clean the bits to remove any grease and reassemble. It usually helps. At least it did in the old days before indexed gears.


How to protect yourself from pollution in city cycling I live in India and have been commuting to office daily on cycle for nine months now. I have developed a permanent sore throat and my skin has also deteriorated because of pollution.

I bought a neo mask (anti pollution), but I find it hard to breathe with it on while going uphill. Please suggest how to prevent pollution from taking a toll on one's body.

There is really nothing you can do. Anti-pollution masks are mostly placebo, and beside making breathing harder, they have close to zero efficiency in terms of air filtering.

Military gas mask would do the job, but for obvious reasons it is not appropriate for biking.


How to replace a Sturmey Archer's cable? I would like to replace the cable of a Sturmey Archer hub, but can't find a way to disassemble the old cable without destroying it, and it puzzles me how to insert the new cable.

To better explain, I have five elements:

The cable
The cable tip 1 (top)
The cable tip 2 (bottom)
The adjusting part (for the lack of the proper term, I'm refering to the cylindric piece that screws into the hub's cable)
The housing of the cable

I haven't found a way to remove the cable (1) because tip 1 and 2 (2, 3) are attached to the cable, and the adjusting part (4) also is attached and doesn't pass through tip 2 (3). The housing is also too small for the rest to pass through.

I wouldn't mind keeping the current cable, but would really like to know how to replace it.

Here's a photo to document this:

Another one showing the "adjusting part":

You are correct. This is different than "regular" cables. On regular cables you pick the end you want and cut off the other. Thats because the connection on the cut-off end is usually a clamp. You run the cable under a screw/nut and tighten it down.

Then you just put a cable crimp on the end to protect the cut cable

However, your internal hub cable is differnet. The cable and housing is really one piece. You have to replace it all together. I have a similar issue on my Shimano internal 3 speed hub. Luckily you can get an entire replacement set (cable and housing).You can get something like this from Harris Cyclery (I only hype them because a Sheldon Brown article was helpful to this post.)

You'll have to make sure that the barrel is the same threading as your "adjusting part" and that you get the length you need. A sales person (or phone call) should get you the exact part. It would probably help to know the model of your hub. It should be engraved or stamped somewhere visible.


If the chain/cog no longer drives the wheel, can this be fixed? Suddenly (without anything sounding like it was broken) the chain no longer turns the back wheel. The cogged part of the wheel is turned by the chain but this doesn't turn the wheel.

Is this something I can fix? I can't see a problem but I haven't started to try to take anything apart yet.

Please note this is a child's bike so there isn't much value in the bike or its parts. Just wondering whether or not to send this bike to the skip.

There are four main possibilities, depending on the quality and age of bike.

The most likely scenario is that the wheel is a traditional kid's coaster brake wheel - one gear forward, pedal backwards to brake.  In that case it's likely that the clutch is slipping inside the hub. A replacement wheel is probably an easy find, even more so than replacement parts, since kids have a tendency to outgrow their bikes rapidly.  If you're feeling wrenchy however, you can take a look here at an extremely detailed teardown and explanation.  You won't need any particularly special tools other than thin wrenches, preferably real cone wrenches.

If the wheel is on a nicer bike with hand brakes you'll be looking at either a freewheel or freehub design.  If it's a freewheel then you've got two possible culprits: you've stripped all the threads off (unlikely) or the pawls are frozen or broken.  In the former case, you'll need to replace the whole wheel.  In the latter, you'll probably just want to replace the freewheel outright - repairing them is annoying.  Replacing it will need a special tool that matches the splines/notches on your freewheel.

The freehub design is similar, except the pawls are in the hub body itself.  You could be lucky and simply need to tighten the freehub assembly, but once again it's probably frozen or broken pawls.  Reparable, but a bit tricky and once again needing some specialized tools.

The last option is that it's some kind of internal gearhub. If it's broken they can be fun to take apart, but you're not likely to get it working again.  If you've got a local bike co-op they might want the donation.


Cube Analog Disc vs. Cube Aim Disc I am willing to buy a new bike and I'm stuck between Cube Analog Disc and Cube Aim Disc. What should I go for? What are the advantages of one over another?

I will use this bike on all kind of terrains (meaning city, off-road, mountain, road), but I won't go mountain-biking (in the real word) very often.

Thank you!

The differences between the bikes are small, and mainly will relate to durability. The quality of several key components is higher on the Analog Disc, which should equal smoother, faster shifting and better longevity of these components.

In addition the Analog Disc is a 9 speed bike, and the Aim Disc is an 8 speed bike. As the current high end models are 10 speed, and 8 speed mountain components are expected to go away in the next year or so, I would recommend the Analog Disc.

They aren't showing pricing, but I wouldn't expect more than a 100-150 dollar or so difference between the 2 bikes.

I hope that helps.


Can a worn drive-train be upgraded incrementally or should it be all at once? It seems like I have a worn drive-train (sad trombone previous question) and should think about improving it.

I'm a little leery about throwing good money after bad into a used bike. Must I buy a new drive-train as a whole or can I buy the components separately and see an improvement? If the latter, in what order should I buy components?

It really depends on how worn out the drivetrain is. The best way to check this is by checking your chain with a chain gauge. If the gauge reads under 1.0 you might be alright with just changing the chain out. If it reads 1.0 or higher (ie the guage at its max reading easily fits onto your chain or even has some play) you probably have a toasted drivetrain.  That is not always the case - sometimes I'm surprised by how worn out a drivetrain can appear yet still be improved with a new chain. On the flipside, which is the more common side, if you have a chain that reads completely worn out chances are the rest of your drivetrain has worn with it and replacing the chain will only make things worse. You'll know pretty quickly if this is the case and if it is you'll to start replacing other components:

Replace your chainrings if you chain jumps or chainsucks in the front. Sometimes you can get away with just replacing middle and/or small chainrings as the largest chainring tends nto to wear out as quickly.
Replace your cassette if your chain jumps in the rear or shifts very poorly or both. With newer cassettes there is no option of chainging individual cogs. It's all or nothing.

If you don't own a chain gauge or you're unsure as to what components need to be replaced, find a good mechanic to inspect it for you. They should be able to diagnose your issues and suggest replacement parts as needed.


Shimano Hydraulic Disc Brakes vs Tektro Hydraulic Disc Brakes My current bike has this brake set: "Tektro HD-M285 post mount hydraulic disc brakes with 160mm 6-bolt rotors and Tektro levers."
I have read many places online that people prefer "Shimano M315, hydraulic disc, 160mm." I am considering an upgrade, but I have yet to see any scientific fact behind which brand is more appropriate for certain environments. Is this truly a matter of opinion or is there factual evidence to prove that one is more efficient and durable than the other?

It all depends on what you are looking for.  Both the Tektro HD-M285 and the Shimano M315 are considered entry-level hydraulic brakes (despite the fact the M315s are over twice the cost), so if your current setup works for you, I wouldn't change it.

If you were looking to upgrade your brakes, I would go with the Deore (M6000) or SLX model (M7000).  At that point you are going to get quite a few additional features.  For instance, the M7000 has tool-free reach adjustment along with a few other weight savings and some minor increased performance upgrades (better pistons for instance).

The nice thing about getting into this upper range is you can easily swap individual components with the higher Shimano ranges.

Personally I would save up for the M7000s.


Advice for increasing endurance Possible Duplicate:
  How can I improve my stamina?

I would like to improve my endurance while bicycling.
I'm especially interested in increasing my endurance while going up a slope (since right now I get tired very easily while doing this and have to stop to take a rest quite often).

What advice would you give me on this?
Do you know any good training program that you would recommend?

Adding a hill repeats workout to your training routine is the best way to increase your climbing endurance. See this video on one way to do hill repeats.

Find a hill with a good grade in your area.
Basically, you warm up and get yourself loose and ready for an intense workout, then ride up the hill making sure to time your effort then use the same amount of time to go back down the hill and recover then repeat.

Start off with a few reps and build up.


What is causing this chain clicking noise? The click only happens when the chain is moving in certain locations. If the gear is low it happens every rotation and if the gear is high it happens 2 or 3 times per rotation of the pedal.

I am trying to figure out if the chain is stretched or somthing is wrong with the cassette.

To explain this more I have uploaded a demostration video of how it sounds.

This happens on multiple gears at different locations on the chain. It happens more than once every turn of the pedal depending on the gear.

Update: measured chain for stretching and looks like no issues.

UPDATE: Fixed by adjusting the cable tension using rear barrel adjuster about half a turn.

A couple of things I see:

I think your derailleur is a bit out of adjustment and is "leaning" towards the lower gears.  It's grabbing on the ramps of the lower gear as it goes by.
Your B screw adjustment is a bit too far away from the cassette.  I would try to get it within a link or link and half.  It looks from the video that you are about 2-3 links away.  See section 4 of this link: http://www.sheldonbrown.com/derailer-adjustment.html

Lastly, is it possible that 9 speed chain (or less) is on that 10 speed cassette?  If the chain is too wide, it would have the same symptoms (grabbing the ramps)


Can I just change straightforward wheel axles to QR skewers? I've just bought a second hand road bike which doesn't have Quick Release Skewers.

Can I just buy a set of QR Skewers and fit them?

Are they a standard size?

Are there any gotchas waiting to bite me if I do change to them?

Is there anything specific I need to look for in order to change to QR Skewers?

I'm not sure if you intend to replace the axles themselves, but AFAIK, most nutted axles are not hollow, which means they can't accommodate QR skewers. If this is true in your case, you will need to replace the axles outright in order to use QR skewers.

QR axles for modern hubs do come in a few "standard" sizes, but you will nevertheless want to measure the dimensions of your frame and hubs anyway, in case they are not standard. You mentioned your bike is second-hand, which indicates it might be older, in which case this is doubly so.

There are three dimensions to check:

Hub spacing - This is the distance from the inside of one dropout to the other. You can measure this by removing the wheels from the frame and sticking a ruler in the dropouts. To replace the axles, you will need to find QR axles and skewers to match your hub spacing.

Otherwise, the QR may be too short or too long for the hub. With non-QR axles, an axle that is too long is not a problem (the nuts will still go on fine, and if you need to, you can cut the excess axle), but with a QR axle, you can't really trim the axle, because the QR skewer can't be trimmed.

Typically, hub spacing on modern bikes is 100 mm (front) and between 120 and 130 mm (rear). Again, you should measure this yourself-- I'm just giving you an idea of what these numbers should be.
Axle diameter - The QR axles you get should match the diameter of the existing axles so you can re-use the existing cups and locknuts (unless you were planning on replacing those, too).

Common axle diameters are between 8 to 10 mm, or 5/16", or 3/8".
Thread pitch - This is basically the angle of the threads on the axle. Like the diameter, this will need to match the existing axle if you want to re-use the cups. According to The Sheldon, thread pitch is measured in either threads per inch or millimeters per thread, with a 1 mm/thread pitch being equivalent to 25.4 TPI.

Common thread pitches include 1 mm/thread, 26 TPI, and (rarely) 24 TPI.


Should I use cheap or expensive lubricant? I'm hoping for either a scientific paper that has looked into this, or at least some plausible statistics from enthusiasts.

This is definitely related to my other question Can I use WD40 and generic bicycle oil to maintain my MTB drivetrain?

However, even if that worked fine for me before, I have a slightly nicer and faster bicycle now, and I'm curious if there is anything at all to be gained from improving this.

If comparing the cheapest and "worst" lubricant versus the "best" lubricant for the drivetrain on a bicycle, what if any performance benefits can be expected? What about other benefits, or disadvantages, such as maintenance intervals, accumulation of debris and particles on the chain?

Basically, is this worth looking into at all?

There are actually some organizations that have tested various chain lubricants against each other. However, some caveats. The easiest thing to test in the laboratory is drivetrain friction. The chain's durability to contamination is harder to test, although one person has done this.

The research is described in this Cyclingtips article. One caveat is that it's aimed mainly at performance-oriented cyclists. Friction Facts did the drivetrain friction test, and found that the worst tested lubricant (White Lightning Epic Ride) cost you about 3 watts of drivetrain friction versus a good lubricant, e.g. NFS, Rock-n-Roll Absolute Dry, two Finish Line products, or even Mobil1 5W-20 motor oil.

3 watts is not a lot of power, though. It is unlikely to cost you a significant placing in an amateur race. I suspect that the minimum difference an average cyclist can perceive is bigger than 3W (albeit I know of no studies of this question).

You also might want to consider durability. For example, some lubricants attract less dirt than others. White Lightning claims that some of its lubricants are self-cleaning, and I got suckered by this when I was a newer rider, but it's very likely untrue in White Lightning's case. Dirt on a chain works like a grinding paste, which is why it's better to keep your chain clean (which, admittedly, a lot of cyclists don't do). Zero Friction Cycling's test reported the estimated running costs of each lube under the test protocol, which involved contaminating the chain gradually and replacing it once it hit a specified amount of wear.

Your question as asked in the title can't be answered exactly. It's more complicated than that. Also, I don't know that the inexpensive oil you report using on your other question was tested for wear; the friction test does report Mobil motor oil, but I'm not sure how your oil compares to this. I guess we can definitely say that people should not use White Lightning Epic, unless White Lightning is giving you chains and cassettes for free. Most people should probably also stay away from Muc Off Nanotube or Hydrodynamic lubricants, since they seem to wear fast and are very expensive. That said, it's probably safe to assume that they're very low friction lubricants (they don't appear to have been specifically tested for friction); if you compete in the Tour de France, then I believe your equipment sponsor will take care of the chains, so you could and maybe you even should use those lubricants. (Alternatively, if you are a competitive road racer, you could also just leave this question to the directeur sportif and the mechanics.)

The article did report that one of the testers recommended not using oil-based lubricants. They generally seem to have higher friction, and their viscosity attracts grit, which damages the chain (but note that the same person said this might not apply in harsh off-road conditions). So, you may be better served by going to a dry lubricant. They recommended one particular lube, which I also use. But other good ones are probably more widely available. We don't discuss product recommendations here, and discussing specific products (aside from the ones above!) isn't necessary to answer the question, so I must recommend you read the article and do your own research. If you have two bikes, you could try out a dry lube on one and see if you can keep the chain cleaner with it.

Aside from that, I have to wonder if most lubricants (aside from White Lightning Epic) would perform adequately if you kept the chain clean. The method you described in your other question doesn't really clean inside the rollers very much. On-bike chain cleaning devices aren't very expensive, and they will brush inside the chain. This should help you get the chain cleaner.


How do I separate hydraulic disc brake pads after pulling the brake while the wheel is off? I take the front wheel off my mountain bike to get it in my car. When I get it out and try to put the front wheel back on, the space between the brake pads isn't wide enough for the rotor. Whoops! I must have pulled the lever on my hydraulic brakes.

How can I separate the the pads without damaging them?

As mentioned try a blunt bladed instrument (A large flat blade screwdriver will do) to pry the pads back in. Just put the screwdriver between the pads and lever the pads apart evenly!
Just be carful though as sometimes the pistons that push the pads out can come out too far resulting in the pistons being slighly out of line, however if the pads have plenty of material left on them you should be fine to just lever them back in with the screwdriver, ther will be some resistance as you will also be pushing against the pistons and fluid pressure.


Replace crankset or cassette for better road performance on an MTB? I few years ago I got into cycling again to help keep fit. I still had my mountain bike from when I did some easy trail riding.

I'm mainly riding on the road now and I was wondering if I can change the crankset or cassette might give me a little more speed. A couple of months into the warm weather and I top out the gears even on a slight downgrade.

There's one very hilly ride I do and the toughest hill I'll sometimes go as low as the second or third lowest gear in the beginning of the season until I get used to riding again. I only ride when it's warm out. If anyone's in the NYC/NJ area it's the hill by the Englewood Cliffs boat basin in PIP.

I have an old Gary Fisher Gitche Gumme (specs in link I think the same year) which has:

Shimano Altus, 24/34/42 teeth crankset
7-speed, 11 - 28 teeth cassette. (Actually cassette might be 8 spd 11-30)
Shimano Altus top-swing, top-pull front derailleur
Shimano BB-CT91E, 116mm spindle bottom bracket

In a year or so I might get a road bike but hoping I can get a little more life out of this one. I saw the Shimano FC-M131 48/38/28T 175mm which I like because I'd prefer longer cranks and also the FC-M311 48/38/28% 170mm which both seem like reasonable upgrades to make to a bike this old.

I have no idea if these will fit the bottom bracket I currently have (which seems fine) or if I'll need a new one. Or would I be better off changing the cassette?

I'm not looking to win any races or set any mileage records just don't want to keep hitting the top gear and not having any resistance while pedaling.

I don't know enough bike parts to know if the 2 cranksets I mentioned are easy to swap on my bike or not and would appreciate input from someone who knows more or recommendations on other cranksets that would fit better. The 2 currently are going for 30USD and I don't want to put more than 50-60 into this old bike.

Update:

I haven't changed anything on the bike. I have been working on my cadence and that seemed to be the best approach. With my increased cadence I'm rarely topping out the gears on level roads. Keeping the tires at the upper range of pressure helped too.

Since you already have an 11 tooth smallest cog you're not going to be able to swap that for a smaller on. Well, you can get a 10T cassette but I don't recommend it, they're designed for small wheel bikes where the faster wear on that cog is just part of the deal.

Swapping to a road triple crankset should be do-able, and with any luck your front derailleur will work with the new one. A cheapish 30-39-50 is about $60 on ebay or amazon, so probably a bit over $US100 fitted if you go to a bike shop. But since you'll need extra chain to wrap around the bigger chainrings, best budget for a new chain and rear cassette (normally those get replaced together. See here and here for why) which will probably be another $100 or so. Call it $250, but ask for a quote because this is a pretty standard swap.

If you're unlucky you might need a different length bottom bracket ($50-ish), or a new front derailleur (plus gear cable, $100-ish). Those are things the bike shop probably won't know until they start fitting parts to your bike, so the only way you'll get a certain quote up front is if they decide to replace them regardless.

That will give you noticeably higher gears across the board, but obviously you lose the low gears (you'll effectively lose your smallest chainring and gain a much bigger one at the other end.

Or fit a slightly larger MTB triple. That will give you less gain in range but is more likely to work with your current derailleur and bottom bracket. You can easily get 28/38/48 sets, and the difference in the top gear between 48T and 50T is small. But that's the problem - you're going from 44 to 48 or 50T, and while either will be noticeable, it's not as much as you might think.

The difference is in how easy it is to go even bigger. On a road triple getting a 52/54T chainring is easy, but with an MTB crankset those chainrings get pricey if you can find them at all. We have a local manufacturer who CNC cuts chainrings, so we can get anything we like. I expect people like that are on the web as well, but you'd have to look (and try to buy local since you're fairly likely to want to swap them when they don't work on your bike because they're too big).

A completely different approach would be to fit fat slick tyres. Or even fat knobbly ones. If you're riding for fitness, the extra drag (and very slightly higher gearing) will be just what you want. Schwalbe make their "fat frank" tyres as big as your bike will take, or "Big Apple" out to 2.5". The big tyres will be noticeably harder to push along at the same speed. And remember, as the cops here keep telling us "the faster you go, the bigger the mess". Going fast just because you can, rather than because you have somewhere to go, doesn't make a lot of sense. I commute ~20km each way on a nice comfortable upright commuter bike that will go 30kph if I push. So I get fitter faster for the same distance ridden. And when I'm lazy I pull out my drop bar racer and do the same ride in 3/4 of the time (33% faster average speed). But I'm more likely to crash on that bike, and if I do it'll hurt more.


Shimano ST-EF51 (3x7) Shifter Compatible With Shimano 200GS (2x7) Groupset? I have an old Montague Paratrooper Bi-Frame with a 2x7 Shimano 200GS and the shifters and brakes need replacing. Will the Shimano ST-EF51 3x7 work with the 200GS groupset?

Cheers,

Yes, as long as the rear derailleur is the same speed, the shifters will most likely work. And for the front shifter, adjust the limit screws so it won't shift to the 3rd gear.


Marking chains permanently for later identification I'd like to mark chains so that I can identify each one out of a few chains of the same model.
Any idea how I can do this in a way that will survive exposure to solvents / lubricants / use on the drivetrain?
Background for anyone interested: I've got a few chains in rotation which I strip back & lubricate in a batch. I'd like to leave one chain installed on the bike while I re-lubricate as it's a bit time consuming, and I'd like to get roughly the same wear across chains by rotating through which chain is left installed while I work on the rest.

Attach a large washer to the chain with some binding wire. Use a centre punch to mark the washer with one to several dots and keep a log of those. The washer will stay attached while you clean the chains and the marking won't be washed off by a solvent.


How do I clean chain grease off my clothes? I commute to work, and often wear my khakis on the ride in. As such, my clothes often get chain grease on them. What products or cleaning strategies do you know that work to remove chain grease from clothes?

Most ordinary baby wipes will get grease out of clothing if you get to the stain quickly enough - or, at least, get enough of it out that the rest will later wash out. You can also carry spray-n-wash pads or keep them in your desk at work. However, baby wipes are also good for cleaning your hands - handy after changing a flat, or fiddling with a bike chain.

However, it's even better to avoid getting grease on your clothes to begin with, so I suggest using a pants clip or rolling your right pants leg up. A full chainguard is great for this, but it's not always practical on a commuter bike. This won't prevent the problem completely, bit it does help minimize it.

For these reasons, I found that when I was commuting, I tended to favor my black or dark-colored pants.


Low Top Tube Xtracycle Donor Frame? One of my most useful bicycles is my 58cm 700c Xtracycle based on a Novara Xpresso cyclocross style frame. Lately, as the kids are getting bigger and my back isn't getting any younger: I crave a much lower top bar. I would consider a used mixte frame, a step-through frame, or other really low diamond frame. Recommendations for sturdy and faithful frame models appreciated. Ability to handle 3 rings and 8 cogs plus a chain stay bridge preferred.

These areas would help me evaluate the frames I might find:

Stability: I have heard some people mutter that mixte frames are "unstable" as donor frames. Is this substantial? (I get some shimmy and flex in my present Xtracycle but I'm running a cro-moly frame but it doesn't bother me.)
Fit: Is there a more limited range of geometry among these frames? Could I find frames like these around 56-58cm or about 19.5 inches? If it is a large "WSD" style frame, how much difference does that make for a male pilot?
Strength: Are frames with lower top bars any weaker?  Steel is not a requirement, but I expect to load it up with camping gear and elementary school
age kids.

Have a look on the second hand market for 'Giant Trail' mountain bikes from a few years ago.  These had an unusual frame design with a lower top tube, wider, more stable bars and disc brakes. Giant Rincon Trail, Giant Boulder Trail were a couple of the affordable models I remember.


Freehub body will not undo Trying to take the freehub body off my bike. The bike is a fairly low end Raleigh Shimano Tourney set up. I got a 12mm hex, inserted it into the hex groove on the freehub side and tried to turn it anti-clockwise. It will not come off. Gone so far as to use fit an adjustable wrench on the hex shaft for more leverage and use a deadblow hammer on the end of it. (Shorter end of the hex not quite long enough to use it in the other orientation that would supply better leverage). Are freehubs meant to be on this tight or am I doing something wrong?

On a lot of the 12mm ones, the part that has the 12mm wrench flats is essentially a nut threaded on to a protruding thread off the freehub body. In that case you're wanting to turn the wrench clockwise when viewed from the drive side or counter/anti-clockwise from the non-drive side.

They're one of the higher torque things on bikes and sometimes threadlocker is applied at the factory as well, so taking a lot of force to break free isn't necessarily a red flag as long as you're being sensitive that it doesn't just feel like you're turning the wrong direction.


Cycling into tunnels I am planning a long trip in Japan (about 1400 km) in a hilly/mountain region. I already know there will be no cycling path and then I will have to share the road with cars. This is allowed by local regulation.

Along the way there will be for sure some tunnels, and besides taking care of being overly visible, I wonder if it is safe cycling there.
Since already crossing a tunnel within a car one can smell the exausts of the other car/trucks, what could be the effect of crossing it at a slower speed and with an higher breath-in breath-out pace?

Should I, when possible, consider alternate routes or I am being afraid of a storm in a tea cup?

EDIT
The lenght of the tunnels can span from few hundred meters to 3-4 km.

Will you be in Hokkaido?

We toured there extensively this summer and cycled through several dozen tunnels: here our findings. They might apply to other parts of Japan.

Newest tunnels on big roads have wide side pavements where you can (and possibly are supposed to) cycle. Safety is not an issue but you might have to dismount to make it on the pavement and it might be only on one side of the tunnel. Lighting is not an issue, we found them very bright.
Slightly older or smaller tunnels still on big roads can have a smaller side pavement, sometime with a fence/chain separating it from the cars. It might be higher than the road or level. Safety is not an issue but if you have a wide load steering can be a bit tight. Visibility can be bad. Bring strong headlights.
Old tunnels on big roads can have a very narrow pavement where you can still push your bike, or you will have to share with cars. You will have to make the decision before getting in, as you might have a chain preventing you to switch. We found just one of those in Hokkaido (Otaru) and while safe, it was unpleasant. Visibility was poor. Surface was mud and sand.
Tunnels on secondary roads you will have to share with cars.

Things to keep in mind: you could have locals riding the other way on a narrow pavement without lights, often peasant/fishermen who are hopping across for their errands. Or pedestrians. Be very careful as you  might see them at the last moment.

We also met several roadworks in tunnels, and a few times on the pavement, with the chain preventing you to get back on the road, but the crews were all extra kind and we sorted it out.

In costal/heavy rain areas you will find sand/mud banks at the entrance of the tunnel or sometimes in some points inside. Not necessarily visible and affecting your steering.

Concerning heavy breathing, tunnels (with one notable 10% exception on a side road on a dam) were never steeper than 6% and this helped. We did not find fumes to be extremely bad, and sometimes just cycling in towns on a slope at a traffic light, for instance, you'd get worst exhaust.

For planning tunnel location, length, and possible alternative routes, refer to "Touring Mapple" (which you should not ride in Japan without!)


Disc brake fork with QR and vertical dropouts: worrisome? The pic below is from the fork of a 2020 Kona CoCo. Eyeballing it, it seems to me that an arc around the disc caliper contact point would pass straight through the dropout. Should this be worrisome? Does the recess around the dropout make this sufficiently (?) safer in the event the QR becomes loose?

As long as the skewer is set with sufficient clamping force this QR disc brake setup should work fine and from a practical standpoint there will be very little functional difference between this setup and a thru-axle.

If the QR is not sufficiently tight (i.e., you didn't set it with enough clamping force), you may notice a small shift in the axle position under very heavy braking. This isn't dangerous but annoying as the rotor will rub against the caliper until you reset the wheel position.  Thru-axles won't do this, but with some care it shouldn't happen in a QR setup either. Even though the axle can shift in some circumstances the axle will not come out as the "lawyer lips" around the outside edge of the drop out will retain the QR.  Even in the worst case where the QR somehow flips open while riding lawyer lips should still retain the wheel in the drop out.  This is why you have to unscrew the QR to get it out of the drop out.  By this point the wheel will be rubbing on the frame, not a great situation, but you won't be without a front wheel.

Now suppose you open the QR, unscrew it a few turns, then go for a ride and heavily apply your front brake... then the wheel will come out of the drop out.  By then however you have made numerous critical errors in the setup.


Finding the correct bike for short tours and daily commutes I am looking for a new bike after my current one has started to fall apart mostly.

As a disclaimer upfront: I have very little knowledge on bikes. For my current bike I did very minor repairs myself (fasten lose screws, etc.), for everything beyond that I mostly went to a shop or asked friends.

I am looking for a new bike to replace my - as mentioned before - falling apart old one. My constraints are mostly on the budget as I am not in a position to spend more than around 300€ on the bike - which I know is a rather tight budget.

I will be using the bike for two things mainly:

Daily commutes to the train station from home. This is a short 5 minute ride that however includes going up a quite steep hill. This for me was a point that ruled out a Single-Speed. Not completely sure here though.
Short tours of up to 20km (~12.5 miles). 80% road. 20% dirt/forest road. Nothing to steep, it's mostly flat around here. I would say >95% flat. The other is bridges, etc. so rather short slopes.

With these things in mind I considered to go for a City Bike. My current one also is a city bike and I think that I don't really need suspension, etc. However I might be wrong here as I never tried suspension before.

I also considered buying a used bike - however my problem here is that I am not sure what to look for here, to see if I buy something usable, or something that will fall apart after a couple months.

So to conclude and formulate a question: For my beforementioned budget and use-cases what would be a good bike-type or specific bike to look at and where should I look for it?

Consider repairing your current bicycle if you are happy with it. Especially if the frame and/or wheels are of high quality and still in good shape. For <300€ you can only get a very cheap entry level bicycle. The same money will easily get you a pair of good tires, shifters, cables, chain, saddle, pedals, stem and handlebar to repair or upgrade your current bike. Repairing your current bicycle also makes sense if you plan to leave it at the train station since an old bicycle (with a good lock) is probably much less likely to get stolen than a brand new one (even if it’s cheap).

If you really want a new bicycle, I’d personally go for something less sedate than a city bike. Go for a hybrid, trekking bike or an MTB with rigid fork (i.e. without suspension). Avoid cheap suspension forks like the plague.


Wahoo Speed sensor: how does it work, exactly? The Wahoo Speed sensor doesn't use a magnet to count the RPM, it's a single-unit and "(...) a 3-axis accelerometer is used to determine the rotation of the hub and thus your speed" (source)

How does it derive the speed from RPM, given there's no need to input the wheel/tyre size at any point? As a matter of fact, I don't think there's even such option in the ELEMNT smartphone app.

Edit: After several people pointed it out I found the option to set the wheel size, which implies that "automatic" is the default. The question still stands: how does "automatic" work?

They use a tiny MEMS gyroscope to measure RPM. These are solid state devices that can measure axial rotation so it can count how many rotations per minute the bike’s axle is rotating. The actual structure of the MEMS gyro is quite interesting (and different from a MEMS accelerometer)- there’s a good description on Wikipedia.

Because the gyro is measuring axle RPMs and not speed directly, it does somehow have to know the tire size  so that it can convert RPMs to travel speed. See further discussion below.

Many MEMS gyros are packaged with accelerometers (the combo gyro/accelerometer is called an IMU) and there are also some with compasses, some with barometer/altimeters, and some are in the same package as GPS sensors - although GPS uses much too much power for a tiny device that is operated by coin cell batteries, so the Wahoo most definitely does not have GPS built into the sensor. If all you’re measuring is speed and you already you know the tire circumference, then all you need is a basic gyro unit.  However, IMUs have become really cheap due to their implementation in cell phones and they allow for more flexibility than gyros alone.

The OP clarified  their device doesn’t need the wheel size so it’s either 1) using an IMU to analyze accelerometer data  to calibrate the wheel size internally against the gyro -- or 2) it's using the receiver/phone's GPS to calibrate wheel size.

1) Using just the accelerometer on an IMU isn’t going to be as accurate as using a direct measurement of the wheel. It's hard to accurately measure velocity from acceleration data, especially when your sensor is also rotating slightly off-axially in space on a bumpy road -- and so to 'cheat',  the sensor CPU is likely doing a rough calculation and then using the closest pre-set in an internal table of values (i.e, one pre-set for 700c wheelsets, one for 26", etc. but it wouldn't be able to tell a 23mm tire from a 28mm tire). However, because most people don’t accurately measure their wheel circumference anyway and just use preprinted cheat sheets anyway, the loss in precision isn’t really of great concern to the end user (see manual calibration note at end).

2) Using the GPS in the receiver would be the most accurate way to calibrate wheel size, especially over longer distances as you can precisely divide (say) 1000 meters by the number of revolutions to get a measurement of wheelsize accurate to 1% (GPS is accurate to about 10 meters) - although any bends or curves would greatly throw off the GPS measurement of linear distance.

Where these inertial units are the most helpful for end-users are in conjunction with GPS at very slow speeds or curvy roads where the GPS has trouble tracking speed-over-ground or measuring distance-over-ground over bendy roads. The data from the IMU can help the receiver better calibrate and ensure that you're properly credited for all those slow, tight hairpin turns as you get KOM.

Note: looking at the manual for the Wahoo, there is an option for entering the wheel circumference directly for when the automatic measurement fails.


22 inch frame mountain bike for someone who is 5'8" I'm 5'8" and had my mountain bike stolen in the fall (bummer!). Just found a really good deal on a 2015 Giant Revel but it's got a 22 inch frame. Would this be unsafe/unpleasant enough that I shouldn't get it? Hard to say no to a deal like this!

Bottom line:
If the choice is between buying a bike that is too large or waiting for the right sized bike then the best choice is to wait.

Much has been asked and answered on this topic on Bicycles Stack Exchange:
How can I tell if the size of a bike is right for me?
Choosing the right bike size
Riding wrong size frame

  Would this be unsafe/unpleasant enough that I shouldn't get it? Hard to say no to a deal like this!

It's a lot like shoes.

Let's say a size 8 shoe is the correct size for you.
There is a really great deal on an amazing shoe but all they have is size 10.

Would you wear a shoe that's two sizes too big?

Can you wear a size 10?
Yes, you can. Anyone who's had to live with the wrong size shoe will be reluctant to do it again. If it was a matter of wearing a shoe two sizes too big or walking through glass barefoot then it might make sense to get the size 10 shoes.

How "unsafe/unpleasant" would it be?
Only you can answer this question because you are the only one who can judge your unsafe / unpleasant level.

The Correct Size

There are good reasons to get the right size bike:
- Comfort
- Injury Avoidance
- Safety

According to a bicycling.com article the ideal size mountain bike for someone 5'8" is 17" to 18" or "Medium"

22" is two sizes too big.

According to the linked article:

  “Investing in a bike fit not only ensures you are going to get the right bike, but you’re also going to be set up on it perfectly, avoiding injury, pain, and discomfort, which will make cycling even more enjoyable than it already is,” Erickson says.

What ever you decide - always test ride a bike before buying.


Must replacement crankset have the same number of teeth? I have a Giant Boulder 520 (1996) and I am upgrading it bit by bit.

I bought a new Shimano 7 speed cassette 11-28T. Now, I want to replace my crank set, however I do not know which size to buy.

Does it have to have the same number of teeth as my current one or does it not matter? I currently have a 42/32/24 crank set, do I have to replace it with a 42/32/24 crank set to avoid having to replace the derailleur or anything else?

I am currently thinking of getting a Shimano crank set FCTY501 42/34/24 compatible with 6/7/8 speed. Will it work with my new cassette and will I need to adjust my derailleur?

You are not changing the largest and smallest chainring sizes, so if nothing else has changed a 42/32/24 crank would be compatible with the rest of your drivetrain.

However, I looked up the specification of your bike on Bicycle Blue Book. The original cassette was a 7-speed 13-28 tooth. You may have problems with the 11 tooth small sprocket.

If you want to check, you can look up the specs for whatever your rear derailleur is. You can find technical documentation for Shimano products on the Shimano Bicycle Components Site.

Rear derailleurs typically have the following specifications:

Minimum rear sprocket size
Maximum rear sprocket size
Maximum front chainring tooth difference
Total capacity

You'll need to ensure that your derailleur can handle an 11 tooth smallest rear sprocket, and a slightly increased total capacity.

The total capacity is the difference between the numbers of teeth on the largest front ring and rear sprocket, and the smallest front ring and rear sprocket. I.e., a measure of the extremes of chain slack the derailleur has to accommodate.

For an 13-28 cassette and 42/32/24 crank: (42+28) - (24+13) = 33, 11-28 cassette : (42+28) - (24+11) = 35.


How can I fix bad elevation data in a GPS log? Lately I have been doing my bike rides with a GPS logger, and its elevation recording is extremely erratic and thus unusable. Please see:

http://gpsloglabs.com/share/d9393bc6c20b8b0debfe26234169be632eb019e0/

You can see from the altitude contour that it does some measurement, but it is too jerky, and thus my total climb is way too big.

How can I work around this problem? Is there any service that will 'flatten' my trip to an accurate topographical map and correct the altitude data?

Try http://www.gpsvisualizer.com. In the parameters set "Add DEM elevation data" to "From best available source". This will replace the recorded elevation with elevation data from a database, which should be more accurate.

Edit: Try this other sub-page of the same site to upload your .gpx and then download the fixed .gpx
http://www.gpsvisualizer.com/elevation


Fox Float RP2 rear shock problem - soft run and hiss sound on first 5-10% of travel I might have a problem with my Fox Float RP2 rear shock (Giant Reign, 150 mm of travel, bike & shock only 6 months old). When pumped to 200 psi, the shock has a considerably soft run and is making a hissing/sucking noise, both on about first 5-10% of its travel. The rest of shock travel seems to behave OK. What do you think is causing the problem? I read about cavitation (when air/nitrogen penetrates oil chamber) and I think that might be my case. With cavitation, do I need an immediate maintenance or can I use the shock like this for the rest of the year and do the seasonal maintenance afterwards?

It might not be possible to give you a 100% answer without opening the shock, but it certainly needs service.

6 months of use isn't a great determining factor for service intervals, hours of riding and type of riding (how big, how dirty) are much more important. Have you rebuilt your air can yet? Do you know how many hours you have on the shock?

You can probably run it for a bit (until winter), but it may or may not make it. Either way, the shock needs rebuilt. Sorry dude.


How do I pack a road wheel for shipping? I need to ship a rear wheel back to the manufacturer for a warranty issue (Mavic).  I'm wondering what the best, most secure way to package it is so that there can be no refutation that 'it was damaged in shipping' or something like that.

What materials do I need and how do I package it?  I want to do it on the cheap because the manufacturer isn't covering the shipping cost.

Wheels generally come in a cardboard box with plastic caps over the hub ends to protect them and a bit of other padding (for skewers and the like) added in.  Your LBS may have a few of these laying around for whatever size wheel you are sending back.  They may even be willing to do the package job for you and save you a bit of time for a reasonable amount of money.  If you just want the materials, I have known some shops to simply give them away (especially to known customers).

The stresses a wheel endures in a cardboard box during shipping are less than what they would endure properly installed on a bike.  Any damage more than that would completely destroy the cardboard box and be evident as a shipping mishap.  I recommend insurance from your shipper to protect against such mishaps.


Why does my bike make noise in certain gears? I'm relatively new to cycling so this question may be obvious to some of you.

When I get into certain gears my chain or drive train makes a noise that I can only to compare to the noise a rollercoaster makes when it starts going up the first hill. (That analogy will either make perfect sense to you or you won't get it at all)

It happens specifically when I get into higher gears on the rear rear cassette.

What could be causing it to make this ungodly noise?

As per the answer by @ian above, not all combinations are viable. Generally speaking you are advised to not use large - large and small - small combinations.

When using both large rings you risk the chain rubbing on the front derailleur and the rear one could be pulled tight enough to cause some catching too.

When on both small rings the rear derailleur can fold right back and cause the to jockey wheel to catch on the chain as it runs underneath.

It's a dark art but check the angle of the front derailleur. If it's fish-tailing out then it could do with some re-aligning. The height above the chain ring could also cause a bit of an issue if it's too high.


Are coarse 3D mesh seat pads effective at keeping your butt cool on a recumbent? The seat of my recumbent has a taut 2D mesh back which is quite good at letting sweat through. That can't be said about the ordinary foam pad supporting the ass. There are special "foam" pads which are really more of a 3D mesh and which were designed especially for recumbent seats:

I only know of one manufacturer of such products, www.ventisit.nl.

Does anyone have experience with a pad like that? When you compare sitting on an ordinary foam pad, sitting on a Ventisit and sliding up on the seat so your ass doesn't touch the seat, where approximately is the Ventisit (or any other similar product you know) on this scale?

Thinking about my stock seat pad - I have a stiff plasticky mesh inside the seat pad, which has a layer of cloth on both sides.  The mesh is an irregular plastic weave, and would be uncomfortable to sir on without a cover.

Thing is, to get the seat back sweaty I've already sweated through every layer of clothing on my back, and lower.  The cloth layer on the seat pad is also between me and the ventilated area.

So I feel that a combination of less clothing on the rider plus more airflow under would help.

Replacing your foam squab with something more open certainly is a good idea.  I'm contemplating something with ribs that run vertically to allow airflow through.

Something vaguely like this backpack design, to keep your weight off your spine, possibly with 2-4 pool noodles or similar:


Disk brake has never worked properly from new, pads replaced - still rubbish! I've got Shimano hydraulic disc brakes and ever since I've had the bike (from new) the front brake has never worked properly. It used to squeak really loudly and perform badly but I assumed they just needed bedding in (taking the bike back to where I got it from wasn't really an option as I bought it from a shop far from where I live (long story)). After riding around 100 miles on the bike with no improvement I decided to get the pads replaced. The squeaking isn't as loud, but it still does squeak and the performance is still rubbish.

I've read about cleaning the pads and discs with alcohol which I've now done and that hasn't made any difference either so I'm all out of ideas.

It's really annoying as I used to have cable V-brakes which worked brilliantly! My friend is also having trouble with his disc brakes and I'm starting to think disc brakes are more trouble that they're worth?!

Any suggestions would be appreciated!

I suggest first checking that everything is assembled correctly. Make sure the rotor is on the wheel the right way round (it should have arrows in the centre). Download the instructions from Shimano's website and check that everything is in the right place and done up tight (but not too tight!) Or tell us what model you have and ideally post a picture.

Look down at the pads and make sure that they clear the rotor on both sides and that they're parallel to the rotor. Squeeze the lever and make sure they squeeze fairly evenly and with no obvious stiction. If the pads aren't parallelreset the capiler - these directions look fairly useful to me and there's a video (that I haven't watched). Basically, loosen the mounting bolts, squeeze the brake lever, tighten the bolts.


What brakes do I need I'm re-building an old bike frame but am stuck on the brakes.

There seems to be a lot of clearance between the frame and rim and normal size brake callipers wont reach far enough. Are there alternative brakes that I need to use?

I've uploaded a pic to help.

Wheel rim looks smaller than what the fork is designed for.

Is that an old road frame? Perhaps it was made for an ISO 630mm rim (sometimes called a 27 inch) but you have installed a wheel with a 700c/ISO 622mm rim.


Help getting the right headset bearings I need to change my headset bearings, however, there seems to be so many different variations out there, and I'm afraid to order the wrong parts.
Why not just order the same type as the old bearings you might ask? Well, they did not really fit; I think the previous owner just had some random bearings laying around that he used as makeshift replacement parts.
So, I was wondering if anyone here could point me in the right direction?
It is an external cup bearing, and the measurements are as follows (measured with a measuring tape, so probably not 100% accurate):
Head tube (inside diameter):
Top: 34mm,
Bottom: 34mm
Steerer tube (outside diameter):
Top: 29mm,
Bottom: 30mm
Thank you!

First you have to identify the type of headset. As you said its a external cup headset, but threaded or threadless?
Measuring the outer diameter of the steerer and the inside diameter of the head tube are also a good starting point. But try to measure as acurate as possible. +/- 0.1 mm - 28.6 mm (1 1/8") is pretty standard on the steerer nowadays, so 29 mm seems to be a weird or wrong value.
Replacing only the bearings would be a headache to figure out.
Manufacturers have a standard description of headsets called SHIS (Standardized Headset Identification System).
This park tools page should help you a lot to identify the required headset.
You have to figure out the measurements and fit the code together like in the example of the page: ZS44/28.6 | ZS44/30 - you can easily search for this code and find the fitting headset.
Good Luck.


What is this part of a bicycle trailer called, and where can I find a replacement? I have a Schwinn double bicycle trailer for my kids, but it is broken.

The black plastic part pictured fits at the base of the right wall and connects it to the trailer frame. A bolt goes through the hole to allow the wall to fold-up for storage.

As you can see the plastic has broken, so the wall of the trailer collapses, making the trailer unusable.

I asked Schwinn customer support and their response was:

  I'm afraid we don't have that part in stock any longer to repair your
  trailer.  You may be able to find the parts online.  I would recommend
  looking for plugs for canopy frame arms.

Plugs for canopy arms doesn't yield any search results for me.

Does anyone know what this part is called?

Where could I find a replacement?

Bicycle Trailer hinge part.

Yes the original is moulded in Plastic but quite easy to replace with a piece of metal.

take a piece of aluminum tube that fits either inside or outside your present tube. Drill a hole through the tube close to the end for the bolt to pass through. Put a bolt through the hole so the hole will not be distorted, then tap the end of the tube down so that it forms the shape that will allow it to hinge up and down without fouling on the  square tube frame of the trailer.
you will have to cut out the rivet that holds the plastic piece in place and replace it with a bolt, use Loktite to stop nut getting loose.

An alternative, use a piece of flat steel about 1.2mm thick and 20mm wide i guess 150-200 mm long. cut out the rivet that holds the plastic moulded part in place. fold the steel into a u shape so it fits around the outside of the damaged plastic part, mark where to drill holes so that the steel strap now holds the damaaged plastic into place and a new bolt goes through the steel and through where the old rivet was.
enjoy cycling again. P


Inexperienced rider - double chainring? I'm a fairly inexperienced (and out of shape) rider who has recently moved to Seattle, a very hilly area. I used to ride a Fuji Traverse (hybrid) in my original hometown, Tallahassee (which also has some hills). The Traverse had a triple chainring, and I found myself using the granny gear a lot on hills. In fact, I'd even sometimes switch down to the big climbing ring in the rear on steeper hills. (Edit: Checking my Strava, it looks like these grades were 7-8% on average.)

I'm buying a new bike now that I'm here in Seattle, as I didn't bring the original with me. I'm looking at entry-level road bikes, but these bikes tend to have double-chainrings. I am aware that triple chainrings usually have gear ratios allowing for an easier time with hills.

Should an inexperienced rider facing hilly terrain buy a bike with a double chainring, or should they always stick with a triple?

I went to college in Seattle and love the town. Very bicycle friendly town.  It does have ups and downs but the bike paths are pretty flat. If you you live on one of the hills then yes you may have a short steep section.

As cassettes have gotten bigger (9+) you can get a pretty big range so triple is less common.  Get a compact up front so you can use a 34T for the smaller. The 8 speed cassette bike you are looking at is 32T so you are pretty close to 1:1 which is a strong climber.  With a 9 speed you can get a 34 with the same spacing for a 1:1.  But a 9 speed will be a jump in price.

As an inexperienced rider with stop and go type traffic of a big city a hybrid or city type bike might be a better choice over a pure road bike.


Endless disc brake issues We've purchased a new e-bike for commuting, its very heavy and carries a heavy load, and the commute is through a very hilly neighborhood. The mechanical disc brakes have become a constant issue, loosing nearly all braking power in usually about a week's time. I've cleaned the pads to remove the glazing (light sanding) and 91% isopropyl alcohol on the rotors, and even replaced the pads, all to the same result - good for a few days, followed by diminished to total loss of braking power over the course of the week. What is wrong with my disk brakes?

https://blixbike.com/products/aveny-electric-city-bike
Tektro Aquila Mechanical Disc Brake, 160mm Rotor

Adjusting the pads is a normal part of maintenance for mechanical disc bikes.

I have a tektro mechanical e-Bike that is ridden with rider+cargo > 200lbs  8 mi/day with 4 steep (> 50 meter elevation change exceeding 20% grade) hills.

I move the adjuster for the moving pad in one "click" weekly when filling tires and readjust the static pad monthly.  I invested money in buying a set of long ball-end hex wrenches, and stopped trying to work a mini bike multi-tool through the spokes to get at the adjuster, it's not really a big deal.

Moving pads in weekly or even twice weekly depending on just how heavy and hilly your idea of "very" is, does not seem extreme.


Can I switch to a new type of bottom bracket? The bottom bracket on my MTB (Cube Analog '17) needs to be replaced, my local bike shop said he didn't have the required piece: a square bottom bracket 115 x 73mm.
Since I can't find this type of bottom bracket online, what are my options?

Can I use a different type of bottom bracket and will that require a change of cranks as well? What's a good choice?
If I purchase a whole new crankset (the original Shimano FC-M3000, 40x30x22T, 175mm), will that include the bottom bracket? Is this hard to install? I found one in a local shop but the specs mention 113mm instead of the 115mm that the shop advised me, I'm guessing this is the length of the bottom bracket and 1mm on each side less won't make a difference?

Thanks for any tips!

my local bike shop said he didn't have the required piece

What? They can't order one? I'd be immediately suspicious and look for another local bike repair shop.
To make sure you order the correct bottom bracket for your crank it's best to look at the Shimano axle length code. The Analog has a Acera FC-M3000 crank. The Shimano square taper bottom bracket axle length code for this crank is 'LL113'. Looking through the Shimano MTB BB specs page we can find that a BB-UN300 has that length code for a 73mm BB shell. Now you know what to look for online (hint).

Can I use a different type of bottom bracket and will that require a change of cranks as well?

Yes and yes. The other choice for a threaded bottom bracket shell (sticking with Shimano) is a HollowTechII external bearings and a 'two-piece' 24mm axle crank. This would be considered an upgrade over the square taper type. You Can pick any Shimano MTB 3x9 HollowTech crank with the same chainring sizes and crank arm length as you have. As an example (product recommendations are off-topic here) the Alivio FC-MT210-3.

If I purchase a whole new crankset .. will that include the bottom bracket?

No. Batteries Bottom brackets sold separately. Shimano two-piece cranks will fit in both a threaded Hollowtech II and BB86/92 press-fit bottom bracket so they do not come with a bottom bracket.

Is this hard to install?

Not really and there are loads of guides online but you need several special tools. To get the square taper cranks off the bottom bracket you need a crank puller. To get the cartridge bottom bracket out of the frame shell you need a tool that fits in the cup splines (there are several variations) and a big wrench or socket driver. To mount HollowTech bottom bracket cups a special wrench is needed. Examples can be seen here. Strictly speaking you need a torque wrench to mount the left crank arm on a Hollowtech crank. You definitely need one to get crank arms mounted on a square taper.
Really, you should be able to get the bike store (or a different one) to order the correct bottom bracket for you. Switching to a Hollowtech crank will be relatively expensive even before the cost of tools. You might look for bicycle co-operatives in your area that will rent out tools or workshop space if you really want to do the upgrade yourself.


Dedicated bike GPS computer over smartphone Yes, I know it's a duplicate of questions that have been asked before, for example this one: Are there advantages of dedicated bike computer instead of smartphone apps?

But I feel that most of the reasons given 8 years ago in response to this question have been invalidated:

The phone is larger → yes, but you still have to have it with you
glare → max screen brightness has improved a lot in recent years
not designed to sit out exposed to hot sun, extreme temps, and rain → not really true any longer, with the arrival of IP67/68 resistant phones
ease of use → new phone apps like Komoot, Strava, MapMyRide, etc. make the phones seriously better for bicycling than 8 years ago
battery life → much improved, with a new iPhone I'm getting at least 6 hours of use on the bike, and that's with the Komoot navigation on; for longer rides, it's easy to pack small power banks.

So my question to anyone who is still using and paying for specialized bicycle computers like Garmin and Wahoo, in 2019, what are you getting out of them that a contemporary smartphone doesn't give you?

I used a phone for about two months, then bought a Wahoo GPS computer in March 2018.
The primary motivation was that

My phone has lousy GPS (Huawei P10).  Multiple times a week, it would claim that I'd teleported half way across town, lose signal and never get it back, or drift so that the track would look continuous but end up hundreds of meters from my destination.  I hear that iPhones have pretty good GPS.  My Wahoo has near-perfect GPS; the worst it does is beep at me in forests on cloudy days because it thinks I've wandered too far off the side of the road.  Some speed sensors can talk to phones by Bluetooth, which may improve phone (and cycle computer) tracking accuracy.

Other advantages:

Size and mounting. My phone isn't big, but it's much bigger than my Wahoo and I found it somewhat inconvenient on my handlebars.
Battery life.  My Wahoo claims 15hrs. I probably get more like twelve, but that means I only need to recharge it about once a week.  Six hours of battery life would mean that, if I set out on a 4.5hr ride without having my phone fully charged and things took longer than I was expecting, I could easily be caught an hour away from home with no GPS and no way to call for help.  Which is to say...
Redundancy. Having a cycle computer and a phone means that I have one device to keep me safely on the right track and a separate device that will give me backup navigation and, in the worst case get me help.
User interface.  The Wahoo has six buttons. While I'm riding, I can press the buttons to get to the screen I want without looking, and then glance at the computer to find out what I need to know. Touch-screen navigation of the phone requires you to look at it and is awkward when things are bumping around. I put the phone inside a waterproof pouch (because, England) but found that made the touch screen awkward to use.  Touch screens are a pain with gloves, too.
Crash resistance.  The one time I've crashed, my Wahoo (and my knees and shoulder) got scuffed up against the concrete in a way that I'm pretty sure would have wrecked my phone, but which caused only cosmetic damage to the Wahoo.  My phone was in my jersey pocket and was completely undamaged and available for use if I'd needed to take photographs or call an ambulance, or a friend or taxi to get me home. Of course, one can easily imagine  a crash in which the contents of one's jersey pocket get trashed, while stuff mounted on the handlebars survives. On the other hand, the phone felt much less secure on the handlebar than the Wahoo does.

In other words, not much has actually changed.  The only thing I've not mentioned that came up a lot in the previous thread was screen brightness.  I guess my phone's screen brightness would probably be fine, but it was kind of moot, as I never did figure out how to stop it blanking the screen after a few minutes of riding.  I'm not sure how my phone would have coped with being in its waterproof pouch on a really hot day; I only used it in the English winter.


What to do with a bent but not broken aluminum seat stay unfortunately I got hit by a car. I was on the main road, in the cycle way and the car had a stop sign coming out of a school. He did see me but got distracted by the kids. Anyway, I was wondering if you could help me out determine is my bike is safe to ride or I should do anything about it.
The rear fork is a bit bent but not broken and it's aluminum. It's a Cube SL bike.
Thanks in advance!

Aluminum alloy is weakened by being bent. The seat-stay is bowed in so that loads will tend to bend the stay more. The stay probably will not fail suddenly, but it will develop a crack where it's bent if you keep riding it.

It's probably OK to ride on temporarily, even if the stay does fail the other stay will support the wheel.

You say the bike is a Cube so presumably you are in Europe. The driver's insurance will cover the damage done to the bike, or you can sue the driver in some sort of small-claims court.


Changing wheel size - what should I know? I own a recent tourer (Dawes Galaxy Plus) and would like to take it over some rougher stuff - muddy bridleways, gravel paths, that kind of thing. What holds me back is the tyres: 35-622 looks to be its limit with mudguards, perhaps 40-622 without.

I'm exploring the possibility of getting round this by using 650B wheels and knobbly tyres. I expect there is a lot to watch out for here, so I want to check my thoughts and assumptions are correct and I haven't missed anything:

Most fundamentally of all, I'm assuming the bike will still handle sensibly with fatter tyres, the fork will still handle the braking force from my discs, etc etc.
I'm aiming for swapping between the two wheelsets to be a five-minute job: just swap the wheels, no further adjustment required.
I think I'd be aiming for around 51-584 tyres because they're 19 mm taller than my present 32-622's, which exactly makes up for the 38 mm loss in wheel diameter. The web advises me these exist and are typically called 27.5" x 2".
I have easily enough horizontal space for wider tyres at my chainstays and fork, but only just enough at the seatstays. If a 51-584 tyre really is 51 mm, then I think I'm OK. I'm not sure a 54-584 (27.5" x 2.2") would fit. Does the 51 mm on a knobbly tyre include any horizontally protruding knobbles, or do they extend beyond the nominal width?
The new wheels will need the same hub spacing as my current ones: 100 mm O.L.D. at the front, 135 mm O.L.D. at the rear.
I have disc brakes, so I'll need the same size rotors (160 mm). I'll also need the lateral position of the rotor to be identical to my current wheelset, but I'm aware the tolerance is very low here and I'm not sure how this is measured, if it is standardised, and if it is easily adjustable (e.g. with shims)?
I'll need a 9-speed cassette like my current one. Somehow I'll need to make sure they have similar levels of wear, to prevent the chain skipping on one and not the other - presumably, frequent chain changes will suffice, though I hope not too frequent.
Last and definitely least, I'm hoping I can use my existing mudguards after a fashion, but they'll be rather narrow so perhaps this is a vain hope.

A much longer post than I thought - nonetheless, have I forgotten anything? And/or please tell me if I'm mad or misguided!

• Swapping the wheels usually needs a little derailleur and brake adjustment, no matter what. You still might need to adjust the high and low limit. And, reposition the caliper, if  hydraulic. If mechanical, most have the pad adj knob, and barrel adjuster.

• Since you're coming from a hybrid wheel, going wider is an issue with the seatstays. But, if you are riding in thicker mud, a narrower rear tire is better. In fact, they way it'll have to work is ideal, with a wider front, skinnier rear. The width measurement does NOT include the knobs. They could rub, if wide enough. But, usually a deep chevron style tread is better for rear mud tires.

• The 650B is coming back into mainstream, after a long-abandoned experiment. So, you'll have more choices of wheel and tire. It will be $$ because of the exclusivity.

• Many wheel sets will have 100/135 spacing. Make sure you get non-thru axle hubs, just the 100x9 and 135x10 QR axles.

• Make sure you get the correct rotor mounting system. Mostly, there is center-lock, which uses a cassette lockring, and then the 6-bolt design.

• The rotors will be in roughly the same position between both wheelsets. I do not recommend extensive lateral dishing of the rotor. It's good practice to be handy at repositioning the calipers. Even taking off and reinstalling the same wheelset can still rub, no matter how perfect the brakes were before.

• Don't worry about similar levels of cassette wear. Replace the chain more often, and use the gears a lot. Nine speed chains came down in price recently. If the chain is worn now, most definitely. But, this discrepancy will happen with prolonged use of one wheelset. If you use both wheels a lot, it won't happen as quick.

• Narrow mudgards obviously won't work as well with fat tires! There could be some splatter.