Is it ok to extend/straighten legs fully while pedaling and will it give me maximum power? When I first got my bike, I had the saddle too low and I experienced some pain in my right knee while riding.  I seem to have "fixed" this problem by raising it some.  However, that got me thinking... what would happen if I raised it even more so that my legs would be straight (not bent at the knee) when the pedal was at the bottom?  Would this give me increased power?  Have power tests been done to verify what level of leg extension produces the most power?  Are there any problems allowing your leg to fully extend (straighten)?  I may try this sometime but wanted to get some info here first.  I asked someone at the local bikeshop and they told me there is a chance of hyperextending if I do that but I asked myself how if the position is fixed?  I think the general rule is to have a little bit of knee flex while the pedal is at the bottom but maybe that is a guideline and not a "hard" rule.

I wanted to add that I don't use any fancy riding shoes or any clips.  Just regular "street" shoes. Also, my typical longest ride in a single day is only about 10 miles max.  That translates into about a little over 1 hour at an average speed of less than 10 MPH.

Also, I am not sure why some people might say it is "bad" to straighten your leg totally when riding cuz when we walk we have alternating straight legs so why not the same when we ride a bike?  When we lift a heavy object off of the  floor, the hardest part is when our legs are bent the most, indicating that is the most inefficient position.  When our legs are nearly straight it is much easier for us to lift weight such as a heavy box that is already at waist height for us.

I seem to have "fixed" this problem by raising it some. However, that got me thinking... what would happen if I raised it even more so that my legs would be straight (not bent at the knee) when the pedal was at the bottom? Would this give me increased power? Would this give me increased power?

Saddle height is a well known as an important factor for power generation on the bike.  There is however a sweet spot. Too low and you don't get to fully use the power range of your quadriceps.  Too high and you will over extend and lose power (as you are heading outside the optimal functional range).

Your optimal saddle height is also affected by your flexibility and position on the bike.  For example, if you are riding a road bike (that has a low slung cockpit position) hamstring flexibility becomes an important factor when determining your optimal saddle height.

  Have power tests been done to verify what level of leg extension produces the most power?

Yes.  This has been studied thoroughly. And while there are lots of general rules of thumb to get you into good starting place, the best possible saddle height is individual specific and depends on your own unique biomechanics (and can change over time).  Saddle setback (front/back position) is another important factor for power generation.

  Are there any problems allowing your leg to fully extend (straighten)?

Yes, this can lead to various repetitive stress injuries caused by how your body compensates for the saddle being too high. Different people may compensate in different ways and get different injuries as a result.

As a personal story, I was on recent short/fast/light tour when at in the final stretch I was getting some knee pains (outside, IT-band related) and I still had 120 km to finish the next day in order to catch a ferry and meet the kids in time for camping.  After much consternation that evening, I tried lowering the saddle by 0.5-1.0 cm (as I was using a different shoe/pedal combination than normal).  This completely alleviated the problem and I was able to ride the distance the next day and make the ferry sailing.

In the end the best advice is to make small changes and wait a bit to see the end effect. Record these changes in a notebook so you can look back and see the big picture. None of this is an exact science because each person has some aspect of their biomechanics that makes them unique.


Is a 650B wheel good enough for a tandem? I'm restoring/updating an 1970 Fresh Tandem that has a 26" wheel (700D x 1.40) and I'm thinking about swapping the wheel set with something a little more modern and accessible like a 27.5" 650B because the frame clears it, provides a little more ride comfort and it looks nice on the bike. However, I'm a little concerned about the weight limit, we're a 300 pound team (135kg) and the bike weighs around 40 pounds. Am I making a mistake here? Here's a quick photo with both wheels on for testing. The old rims are 50 years old, the tires are extreemly difficult to find and I'm planning on swapping the freewheel with a 9-speed cassette anyway.

The rim size is immaterial to the strength of the set you choose.

Many rim brake 650b rims out there would not make good tandem rims, but there are exceptions. The VO Voyager or Diagonale in 36h are the main ones I can think of. Sun CR-18s are another, cheaper possibility. Also Velocity Cliffhanger or Atlas.

650b is likely the right choice for a conversion. If you happen to be maxing out your brake reach at present that could be a curveball, but at a radius difference of 1.5mm it's probably fine.


Derailleur problems - rear mech slipping forward I have been riding my Trek Fuel Ex 8 for a few years now, and as I have improved, I have been attacking more challenging terrain.

I have started to notice a problem in my rear mech - the link arm screw that holds the mech to the dropout seems to slip and cause the whole derailleur to swing forward until the cogs are sandwiching the chain against the sprocket. Now I'm no doctor, but I can easily say that sort of cramping is bad.

On the trail, where this mainly happens, I have been able to repair the system by pulling the whole mech back as far as it will go (there seems to be some sort of physical block or stop in place, so I don't think I'm going too far) and tightening the screw that is allowing the slippage.
Now that seems like problem solved, right? My question is this.

Firstly, is that the correct procedure to reposition and fix the mech, or am I doing something wrong?

Secondly, how tight must this screw be? Wrenching it as hard as I sensibly and safely can with a park tool only holds for a while, and then the problem repeats. Also, how would you measure tightness? (I feel like there is an obvious answer there that I should know already...)

Finally, given the problem occurs on the trail, and specifically I think on landings and rough patches, is there something in my riding style that could help prevent damage. Advice is welcome, but I'm not an absolute beginner.

Thank you for any help on this

I have started to notice a problem in my rear mech - the link arm screw that holds the mech to the dropout seems to slip and cause the whole derailleur to swing forward until the cogs are sandwiching the chain against the sprocket. Now I'm no doctor, but I can easily say that sort of cramping is bad.

Strange that this would be where things are coming loose. My recommendation is to remove the rear wheel and chain and make sure nothing else is coming loose either. If it's just the connection to the hanger, check the threads on both the derailleur and the hanger as one or the other may have damage or contaminants. Clean and lube/locktite the bolt and re-install the derailleur. If you continue to have problems, I'd have a mechanic check it out.

  Secondly, how tight must this screw be? Wrenching it as hard as I sensibly and safely can with a park tool only holds for a while, and then the problem repeats. Also, how would you measure tightness? (I feel like there is an obvious answer there that I should know already...)

Park Tool recommends 8-10 Nm or 70-86 lb-in. You can easily measure this with a torque wrench, you can get a cheap one from a hardware store or go for a more expensive one if you want something that lasts.

  Finally, given the problem occurs on the trail, and specifically I think on landings and rough patches, is there something in my riding style that could help prevent damage. Advice is welcome, but I'm not an absolute beginner.

Just trying to stay smooth is about the only advice you need. And don't land to flat! That puts a lot of stress on everything.


How can I identify if my 'Cinelli' frame is real & what model it is? I bought a road bike off ebay. Which is supposedly a Cinelli from the early 90s / late 80s. How can I identify the model?

Assuming no decals or identifying markings, call Cinelli with the serial number which will be stamped into the bottom bracket shell. Otherwise, with no pics and no description, telepathy is the next best option. I don't posses that skill.


Cleaned wheel, V-brakes are now moaning Yesterday, I cleaned my 5 months old bike using WD-40 Bike HEAVY DUTY DEGREASER and removed some dirt and brake material residue from the wheels. Now my front brakes moan.

I did go through this question and I did set toe-in to around 2 mm, which helped somewhat. Now it's just moaning, not moaning like an old train braking.

I also sanded the pad surface a tiny little bit with a 2000 grit sandpaper. The pads are clean and free from any derbies or foreign particles. They still have some 3 mm before the wear indicator.

The wear on the pads looks mostly even, but there's a bit of unevenness due to the wheel rim wear indicator, but I checked and those points are making good contact with the interior of the indicator.

I'm not really sure what to do now. Most of the searches provide me either with the toe-in solution or give results for disc brakes.

Do NOT use WD-40 of any kind on your rims if you use rim brakes. WD-40 leaves a residue. If you have contaminated your rims, clean them off with rubbing alchohol. Once you do that, it'll be like starting with new brakes, so they will take a little brake in to get dirt and rubber re-imbedded in your rims. If the pads have been contaminated with WD-40, and it sounds like they have, replace them. Pads are cheap.


Fit thinnest road tyres (fat ones at present) to terrain bike Outpost GT Can someone please decipher into common language this wheel/tire info?
Rough wheel dimns (by measurement) apprx 57 cm largest dia. x 25mm apprx rim width.
To fit H/E rim?
Tyre fitted Kenda K898-005
54-359.
I want to fit thinnest road tyres (slicks?) on these rims.

Please advise ('cos I'm not even sure of the wheel size in lay language)
thanks
Peter

The K898-005 is a Kenda model code that no fitting information can be gleaned from directly. The 54-559 (you wrote 359) is the ISO measurement. The first number (54) is the approximate outside width of the inflated tire in millimeters, approximate because it varies slightly depending on the rim width it's mounted on. The second number is the diameter of the circle formed by the tire bead, which corresponds to the bead seat of the rim. 559 is the most common of the 26" sizes, sometimes known as "mountain bike 26 inch" and similar names. It's probably the actual most common size in the world, but there are a couple of other 26" sizes, and when getting 26" road tires it can be easy to accidentally get one of those instead because they're more commonly associated with thin tires. So don't buy a tire that says 571, 584, 590, or 597. You want it to say 559. Most but not all tires for 559 are going to have their width described with a decimal rather than a fraction (26x1.125 rather than 26x1-1/8 for example). Most but not all currently produced tires have an ISO number hiding somewhere on them, so you're looking for something that says xx-559, where xx is width.

As for the minimum width, for practical purposes you want something that ideally has 2-3mm overhang past the rim and is under no circumstances narrower than the rim. So 26x1.25 (32-559) is the start of the reasonable widths, 26x1.125 (28-559) is pushing it, and 26x1 (25-559) will more or less physically work but is kind of asking for trouble.


When to tune/replace brake cables for optimum tension Original Question

What physical symptoms do I need to look for to understand that my brake is out of tuning or the cables have reached end of life?

It is not necessary to consider the brake shoes in this question as I already have a previous question on bicycles SE covering that.

MY USAGE
I ride everyday for work and fun. I cover about 20 miles on average every week but would be doing a lot more than that.

MY REASONS FOR THIS QUESTION

I have been tuning my front and rear brakes by either releasing the nuts near the handle or just adjusting the cable near the brake (i.e. where the noodle is). It seems that they are running out quicker than I though (i.e. running out of tuning). I really don't know what to do anymore. I know that a really bad way to do this is just replace the brake cables, but I just almost bought the bike (November 2012). I think there are better ways of tuning and managing the brake performance. I have attached some pictures for the users to see what I am talking about.

The posts that I found on Bicycles SE and youtube are not really helping me for this. My brakes run out of tuning a bit faster than I thought. If I am doing something wrong, a slap on the wrist will be appreciated!

TIA

UPDATE SINCE @DANIELRHICKS POSTED HIS ANSWER

I have replaced my brakes whilst you folks were reading this and resulted into the followings now. Could anyone tell me if it seems wrong? Also, I am not sure if angle of my V arm of the brake is correct. Do I need to fix that too?

WHAT I HAVE DONE TO FIX THE TENSION ISSUE

Once the brake pads are replaced. I opened up the nut to the maximum i.e. created the highest tension point.
Adjusted the cable attatchment (i.e. the attatchment of the cable with the allen-key joint near the noodle).
Slowly closed the nut inside (i.e. loosen the cable tension) so that the necessary gap between the pad and rim can be achieved, also the cable attatchment near the noodle is appropriate.

Normally you replace a cable when it becomes too badly rusted, or the cable inside begins to break.  The first condition you notice because the cable does not move freely, and the second you notice because the brake levers "give" (and don't bounce back) when you squeeze them hard.  If not rusty, a set of cables can easily last 10-20 years.

In your case it seems likely that the brake pads are simply wearing rapidly.  With V brakes, for 1mm of pad wear you'll need to take up about 3mm of cable slack.  If you're having to adjust the cable too often you may wish to change out your pads for something harder (though note that this will reduce braking power).


Shimano Chainring Set I have a Shimano Altus 8-speed on my hybrid/commuter bike. I have to put in a new cassette and a new chain as well and looking at the teeth of the largest chainring cog in the front, it looks like the teeth are pretty worn as well.

I expected the chainrings to be replaceable individually but was puzzled to see that they are one solid unit. It kind of looks like a chainset but the pedal part seems so be attached by a screw and does not appear to be part of the chainring-set.

The largest cog has 48 teeth and has 4 extra holes to attach a chain protector.

Does anyone know the name of the part and a supplier in the UK?

Would it be advisable to invest in a chainset where I can replace individual cogs? What would be a possible part combination?

While cleaning I found the part number printed on the inside of a crank handle. It is a FC-M191. This part seems not to be available in the UK anymore so I decided to buy the MC-M411, which has the same teeth number for all three cogs, is suitable for 8-speeds and has the same Shimano rectangular axle fitting as the FC-M191.

I also bought a Tl-FC10 crank pull to disconnect the cranks from the bearings.

It appears that the derailleur is an Altus but other parts have been used for the Chainset in the front. This makes it difficult to find the matching parts.


Suitable upright bar brake lever for old caliper brake I want to replace my existing drop bar and levers with an upright bar and brake lever that will work with the old side pull weinmann synmetric 733 brakes, that are long reach at 65mm according to Sheldon's measurements of caliper brakes. Am I right in assuming that long reach and long pull are two different things and the upright levers I need are standard pull?

Yep, 'reach' is how long the brake calipers are, and an indication of whether the brake pads will hit the rim properly.

'Pull' is basically how spongy your brake levers will feel.  If this is not matched properly to the brake calipers, you could end up with jerky brakes that are very on-or-off and liable to catapult you over the handlebars, or ones that are just too soft for the job.  Some manufacturers (modern ones?) specify which brake levers to use with their calipers, but inevitably they recommend their own ones.  This doesn't mean that others won't work well, but that might be more a matter of trial and error and reading around.

I'm about to rebuild my front end (new brakes, new levers) and my best advice is buy from a website (or shop) that has a decent returns policy!


Why have 29-ers arisen only recently? I have been hearing for the past months about twenty nine inch wheels for bikes, and seeing such at the showroom windows and on the street.

Also heard that they have a lot of advantages and a couple of drawbacks.

My question is why now? The diamond frame has been around for ages. I suspect the disc brakes and, later, the hydraulic disc brakes were not introduced right away due to technological limitations. But the size of a wheel is certainly not constrained by technology.

So why is this new fashion emerging exactly now?

Although 29ers have been around since the early 80's they have only been in production from a major producer for the last decade. Trek was the first big brand to offer a 29er in early 2000's.

Reasons why you may not of seen many are:

Until the last couple of model years model years 29er's have predominatly been in the XC category (HT and FS)  while recently more all mountain and trail bikes have been developed. Depending on what riders were doing in your area there may not have been a market.
There has been an increase in world cup/ champs and olympic riders using 29ers in the past few years. At the 2012 Olympics there were very few 26" bikes in the mens (more in the womans due to size.

People don't change their bike that often. If you live in an area where there is not a lot of riders the market for a new wheel size retailers will stick to what they know.
Entry level bikes have predominantly been 26". Big box store retailers (of which makes up a large portion of the market) will follow the trend for what they see selling the most of. Now there is a critical mass of 29ers they will follow.
Most people don't read media about bikes they are driven by what a salesman says, which will generally be in the direction of the most sales and biggest margin.

I do find it interesting that you are commenting that you see a lot of 29ers retailling where you live, in New Zealand apart from XC bikes a huge proportion of the 2014 model years bikes that I am seeing at the moment are 650Bs. I think our market replicates that of the US where companies are moving to this as the new "standard". A good example is Giant who have committed to phasing out both 29 and 26" models on a 3 year glide path. Other manufacturers are offering strong 650B models in intemediate and advanced AM categories this year such as GT, Trek, Merida and Santa Cruz just to name a few.


Shimano chainring / crankset compatibility I discovered a Shimano FC-2300 Crankset (175-mm 52/42/30T 8 Speed) for $62 on Amazon - is this compatible to replace my old FC 3301/3304?

The longer story is I need to replace my Shimano chain (CS-HG50) / middle chainring from an SG 52-42-30 set (and I expect rear cassette too?) after 5 yrs of a modest commute on my 8 speed flat bar bike.
Can anyone recommend an online seller of suitable replacement parts compatible with the Sora FC 3301/3304?  My local shop in Perth Australia proposes to sell me a new bike, but I'd rather repair to safe and functional level - I won't be winning any races on this unit:)
I'm new at the repair work and tho' I've got a chain tool, it appears I'll also need to get special tools (crank extractor?) to get at the chainrings?  Do I also need special tools for to replace the rear cartridge?
Thanks in advance,
Chris

The answer is yes you could replace your crank set with the FC-2303 but you would have to change your bottom bracket also. Look up the Shimano tech docs for these cranksets, all the information you need is there as well as the steps you take to change the bottom bracket.

The triple ring crankset is the FC-3304 with a 45mm chain line using a 118mm octalink bottom bracket.

The FC-2303 is the triple ring crankset which also has a 45mm chain line but uses a 113mm square taper bottom bracket.

So alongside the crank extractor you will need a bottom bracket tool. I got a crank extractor and a BB tool for about $10 NZD each. To change a rear cassette you will need a lock ring nut which will fit your rear cassette.

I shop at Chain Reaction Cycles which ships from the UK and is cheap and reliable with fast shipping. They sell components and tools at good rates with ok shipping rates.


Can you get your cycling helmet wet? I have bought this Bontrager rally helmet and I was wondering if it does any harm to it if it gets wet eg. In the rain

Of course no, it doesn't do any harm that the helmet gets wet in WATER.

It is made of various plastics, which per se are insensitive to water, and also it is supposed to be worn even though the cyclist is cycling under rain or snow.

Also, your sweat is basically water and some salts. If water was dangerous to helmets you should not sweat when wearing them :)

Just avoid that it gets wet by organic solvents (acetone, benzene, etc.), as they might attack some of the plastic and drastically alter their mechanical properties, leaving to your head the same protection offered by a shopper. The advice to not paint or put stickers on the helmet comes from the above point, as some paints or glue can contain non suitable solvents.


Persistent front wheel squealing: Replace the fork? Switch to disk? I have a Cannondale touring bike from the early 2000s that I use as my daily commuter.  With the stock cantilever brakes and original front wheel, I had a lot of front brake squealing.  I did the standard maintenance to try and make it stop (toeing, sanding, etc), and it returned persistently.  I've even replaced the front wheel (independent reason: got a dynamo) and the brake calipers (Avid Shorty), all to have the squealing come back.

This isn't just any minor squeal, this is "audible from 100 yards, plug your ears, the bike is screaming in pain" kind of embarrassing noise.

Would it be possible that it's the canti mounts on the forks that are causing the squealing?  Would replacing the fork be a possibility for fixing this?

I've been thinking that I might try switching to disk brakes, but I don't want to just have a different kind of squealing.

I already have a disk-compatible front hub (Shimano Alfine dynamo hub with CenterLock), but I'd need to get a new fork to get the tabs and calipers.  I don't want to throw away $200 (fork + brakes) if I'm just going to be squealing again or subject to a different annoying noise.

Would it make sense to do this in stages?  I.e. get a fork with disk and canti tabs and try that, and if the squeal returns try the disk option?

I switched from an aluminum fork to carbon and the brakes howled like crazy. I went the usual route of cleaning, adjusting etc. What worked is counterintuitive, but I toed the shoes out. The noise went away immediately. I read somewhere that it can have something to do with the harmonics of the carbon fork.  So I have the rears toed in and the front toed out and there is no noise.


Joe Blow Pump Maintenance My Top Peak Joe Blow floor pump has been getting harder and harder to pump. I bought the high end model so that my 94 lb wife could pump up her own tires, but it has gotten to the point where I can barely get my own tires to 110 psi.

Is there some maintenance that I'm supposed to be doing on the pump?

I found a rebuild kit online, is that the ticket to making it work better?

What precisely is wrong with it?  If it's got high friction when you work the pump without it connected then working the right kind of lube into the cylinder would do the trick.  (Not sure what the "right kind" would be, but definitely NOT regular oil.  Probably either a glycerine product or a silicone product.)

If it's leaking air back through the cylinder then lube might help, or you may need a new "leather" (which is no doubt plastic/rubber).

If it's leaking through the "chuck" that fits on the stem then some lube there may help, or a new gasket.


Changing Shimano 105 triple chainset to compact I'm looking to buy a used 2015 Cube Agree GTC Race. The only drawback is that it has a triple chainset, and I would prefer a compact. Which parts might I have to replace apart from the chainset itself?

To go from a triple to a compact, you generally need to switch the front derailleur for one for doubles (make sure it can be attached to your frame and the right cable pull; front derailleurs have different cage shapes between doubles and triples), the front shifter (if indexed; you need a double shifter rather than a triple shifter, and it needs to have compatible cable pull with the front derailleur) and if you're using a bottom bracket with a spindle (like a standard JIS/ISO bottom bracket, Octalink, etc.), you may need to have a different spindle length (to get the right chainline). And of course, you need the compact crankset (which is compatible with your bottom bracket).

In your case, you have a hollowtech II bottom bracket (with a Shimano road group), so you need:

Compact Crankset which fits hollowtech II bottom brackets (reasonably common; Shimano, FSA, etc. make them)
Shimano road double FD (cheap; you can get tiagra or higher for only 20-50 USD)
Shimano road double shifters (Expensive; you only need front shifter for a double, but you may end up getting  a set in which case you need to match the rear number of speeds as well).

I'd suggest trying the triple for a while -- you may end up liking it despite it not being in vogue.


What causes and how to fix wandering bite point on Shimano hydraulic brakes? For the last two months and less than 600 km of riding I have been using a pair of new Shimano SLX BR-M7120 "high power" 4-piston hydraulic disc brakes. Yesterday I have noticed that the bite point of the rear brake started to wander, i.e. the lever travel required for brake engagement changes.

Specifically, when pulling the lever a few times in quick succession, i.e. when pumping the lever, the travel shortens considerably (up to 1.5 cm at the finger position, depending on how fast you pump), so that the brake bites sooner, with the lever further from the handlebar than normally. The lever never sinks closer to the handlebar than normally, i.e. the bite point always wanders to the outside.

The brakes have been bled very recently and the lever does not feel soft nor is the braking weak. Combined with the fact that the lever never sinks, I am not sure this is due to air in the system.

This is quite a frustrating and unsettling issue in general and especially when hurtling down very steep and rough terrain (which these brakes are meant for) where it is dangerous both to go too fast or too slow, one of which you are likely to do if you cannot tell when your brakes will engage. So as the question says, does anyone know why this happens and how to fix it?

Some additional info:

front brake is also affected by this issue but to a far lesser extent; the lever has to be pumped faster than it would be during any realistic trail riding situation
problem first occurred in wet and cold weather (just above freezing), however I've ridden in the same conditions a few times before without noticing it
the brake is not damaged and, apart from this issue, works great

Originally I gave a tentative answer to this question and proposed the solution without actually trying it (next three paragraphs), and now that I have tried it I expand the answer with a report on the results (last two paragraphs). Spoiler: as already verifed in the meantime, the solution works perfectly.
Firstly, this is not a bleeding problem. I verified this by thoroughly bleeding the brake using fresh original Shimano mineral oil, after first draining the system to make sure I really do use the proper fluid in good condition. I also took the opportunity to clean the pistons and "lube" them a little with the braking fluid, just to eliminate dirty/sticky pistons as a possible cause of the problem. The bleeding was done at room temperature and the results were excellent; great lever feel, sharp engagement, consistent bite point position. However, after I took the bike for a test ride through the neighbourhood, with the outside temperature just around freezing, as the system cooled to the outside temperature the wandering bite point reemerged, i.e. the lever would "pump up" (engagement would begin earlier). The corresponding effect, to a smaller extent, emerged at the front brake as well.
Given this test and the information I have gathered at various places on the web, I conclude that the cause of the problem is the high Shimano mineral oil viscosity at low temperatures (viscosity being, in layman's terms, the resistance of fluids to flow freely; water has very low viscosity and flows easily, while e.g. honey has high viscosity and oozes slowly), combined with the small orrifices of the Shimano levers' inlet and compenstaing ports through which oil flows between the master cylinder and the brake fluid reservoir. Namely, instead of the oil flowing to the reservoir through the compensating port as the pistons are retracted after braking, the oil stays in the main line, so as the lever returns the pistons do not yet retract fully, meaning that on the next braking they are extended closer to the disc and therefore bite sooner, with lever further from the handlebar. If given more time, the oil slowly flows back in the reservoir, the pistons retract fully, and the bite point returns to its usual position. Hence, the bite point wanders to the outside by amount dependant on how often you engage the brake; at low temperatures, you can pump up the lever so that there is almost no free stroke before engaging.
The solution I have read about and intend to apply is to swap the original Shimano mineral oil  with a low viscosity oil that has small viscosity variation with temperature (i.e. a high viscosity index or VI; Shimano's VI is pretty low, apparently, meaning it gets "sticky" at low temperatures). I believe this nullifies the warranty, but I have found there are many people, especially in Germany, who have been doing this for years using one particular motorcycle fork oil. In fact, this is so widespread that this oil, Putoline HPX R 2.5, is considered a benchmark on their forums, and if you try to buy it on German Amazon, at the time of writing 7 of the total 8 reviews rave about its use in Shimano brakes, the eighth also lists this as one of the uses it is good for, while Amazon auto-suggests Shimano bleeding funnel as an additonal item to buy with this moto fork oil (!).
After I actually try this, I will update this answer with a report on the results.
UPDATE: Roughly a month ago I finally bled my rear brake with Putoline HPX R 2.5. The bleeding was as easy as usual if not easier, as the less viscous Putoline fills the lines more quickly. Since then I have had several snowy rides at temperatures well below freezing, down to under -6 °C (under 21 °F). The wandering bite point dissapeared completely and the bite point became perfectly consistent, i.e. the lever neither pumps up nor sinks. I cannot even reproduce the wander deliberately by successively puling the lever as fast as I can while standing over the bike, let alone while riding. For comparison, I still use regular Shimano mineral oil in my front brake, and now that the rear brake is completely wander-free, even the small „pump-up“ I previously felt in the front feels huge. As for the performance at warmer temperatures, the highest in the last few weeks were about 15 °C or 59 °F, and the brake felt great. Apart from achieving predictable and consistent bite point in the entire range of riding temepratures, I could not really feel any difference compared to using Shimano oil; the lever action on both sides feels firm and safe. As for the seals, there are no indications of any adverse effects of Putoline whatsoever, let alone leaks.
Given this experience, which has now also been confirmed by others (see answer by Gareth D), and the fact that Putoline is also cheaper than Shimano mineral oil, I can only recommend using Putoline HPX R 2.5 as a solution to the wandering bite point problem to anyone not worried about the warranty of their Shimano brakes. Come next bleeding, I will start using it in the front as well.


Modern bike security, a lock with GPS and SIM card? These days many things are getting GPS and these things often also have a SIM card, so they can connect to the internet. (I think some call this internet of things)
Is there any bike lock out there which incorporates these ideas?
Perhaps a device that sends a signal every i.e. 5s to the internet, and I can think of an app on my phone which then checks for this signal often. And trigger an alarm in case the signal isn't received.

Sophisticated bicycle GPS trackers have been on the market for a while now. You can even get some that can be hidden in the seatpost or handlebars and the battery life will be different on different trackers and how regular you want the  GPS reporting.
Smart locks do exist, but having a conventional lock, one that isn't permenantly fixed to the bike, is not much use (IMO) in the event of a theft, thiefs rarely take the broken locks with them, and by the time you get to the location of the theft, they will likely be gone.
A bike lock such as the I lock IT might be something to consider, although without knowing the bike you plan to protect, I can't advise on compatibility.
I don't know of any conventional bike locks with SIM and GPS functionalities, there are some with bluetooth-like alert systems, but you would have to be within Bluetooth distance of the bike.
You can also consider GPS tracking bicycle lights. Although, if you live in a place with bike light theft is high, this might not be an option.
Personally, I would invest in good bicycle insurance (and Gold Standard lock) before looking for any GPS systems. Bare in mind that difference insurers will have differe policies on claiming for bike theft, triple check all the small details required before thinking you are covered. This might include what lock you use, what you lock the bike too and where on the bike you place the lock.


Does a singlspeed conversion kit feel different than a freewheel? I'm trying to get a steel singlespeed and I find it quite hard to find something in the market that is light and with brakes.

Will one notice any difference if, for example, one gets a Cinelli Vigorelli road frame:

with a kit like this:

compared to a similar bike frame without brakes used for track races?

Is it noisier, less stiff or something like that?

Riding the bike, the only thing you would potentially notice is if there's any difference between the rate of engagement of the two ratcheting mechanisms being compared, i.e. that specific freehub versus specific freewheel, and also any differences in how noisy they are. Examples exist of each that are more or less noisy or quick-engaging, so there is no universal answer.

Cassette hubs made for derailer use and converted to singlespeed via spacer kits have the disadvantage of being weaker and less laterally stiff than dedicated singlespeed hubs, because the drive side bracing angle is steeper and there's less total spoke tension. That could be noticeable depending on the rider and circumstances, especially if you're pushing what your chosen rim can handle strength and stiffness wise.


Dual position air, solo air, coil, rebound: what do they mean about forks? Lyric is available as Dual Position Air/ Solo Air / Coil. What do those terms mean generally?

My speculations are leading me nowhere. If Dual Air means no hydraulic cylinder, how can the fork have Damping:    Rebound? Solo air is pretty clear, but what about coil - is it a coil in one boot and hydraulic unit in the other, or two coils?

On a related note, do there exist shocks with both air and coil spring in the same time? If so, what is the point? How can one discern them?

There are two parts to a fork, the spring and the damper. Solo air, dual air and coil are all types of spring and absorb energy when the fork is compressed. The damper, which is the part of the suspension system that removes oscillation after the spring has absorbed energy and is returning, is generally a hydraulic system filled with oil. The Lyric has an oil damper as well as a coil or air spring.

A modern air spring generally has two chambers one positive and negative, the positive provides resistance against compression and the negative resistance against rebound as the spring returns to it's normal length.

Solo and Dual air are RockShox terms for their proprietary air spring system and relates to the way the shock is filled, but both are dual chamber. Until Solo air forks became available (2012 or 2013 forks) it was necessary to tune both chambers to get sag and rebound correct, now solo air is a single fill system that does this much more easily. Dual air (as opposed to dual position air) has now been replaced completely by solo air on the RockShox range.

  Dual Position Air

  Dual Position Air is another proprietary RockShox technology and is a
  type of air spring that allows for travel to changed between two travel lengths through a lever on the crown. It acts in the same way
  as a solo air spring but gives the rider greater choice on a ride.

A coil fork uses a mechanical spring in place of an air spring. A coil spring is simply that, a big metal spring.

The benefits of the two types are often debated. A dual chamber air spring fork is lighter than a coil spring but requires more tuning. A coil fork has a finite stroke length so the rebound is smoother at the end of the stroke and makes the fork feel more plush throughout the stroke.

It would be redundant to have both a air spring and coil spring in a fork, as both are springs and neither are dampers. The fork would bounce back and oscillate (bounce up and down like a spring until all energy was released). There have however been bikes with two stage suspension systems like the Elite9 which used dual rear shocks and could effectively line up a coil and air spring shock.


Book Recommendation: Training I am curious if anyone has any interesting books (preferred) or blogs on training for cycling.

Right now I ride for a couple hours twice a week, I have a short 15 min commute to work and I ride for half a day every weekend.  I just moved to a new city so I am mostly riding by myself but I want to improve my speed, distance and fitness.

I was hoping that someone could suggest me a good book about cycling training.

It should be "The Cyclist's Training Bible: A Complete Training Guide for the Competitive Road Cyclist" by Joe Friel.

It is considered one of the best books about cycling training, even if you are a mountain biker - endurance training needs to happen on road as you need to maintain reasonable heart rate for lots of training types.

The book has been published several times, the most recent edition in June 18, 2009

After reading it, you can also read Friels blog.


Clicking Sound with the Bike Stopped I have a Giant E-Bike and I've just noticed that it makes a clicking sound when it is stopped, the front brake is applied and it's being pushed/pulled with the handlebars.
I've removed the brake calipers to check movement in the pads but this does not appear to be the problem.

First thing I'd check is the headset assembly, even on a new bike. Eliminate it by dismantling, then greasing all the surfaces and reinstalling with careful adjustment. Even applies to brand new bicycles occasionally.
It could be something else, perhaps spokes moving or qr axle, the stem or some part of the brake as ideas. Whenever you're creak-hunting, check and grease or substitute only one thing at a time before testing it out so you can isolate the problem.


Self extracting crank preload This question got me wondering about self-extracting cranks: What bottom brackets are compatible with Miche Evo Max cranksets (self-extracting type)?

Where I've seen them on cartridge bottom brackets, I take it for granted that the crank bolt tightens the crank onto the splined axle and helps hold it there (i.e. 40Nm torque).

But, how is the crank held onto the axle, are the splines tapered and holding everything together (once it's on, it's on), or is it reliant on the crank bolt keeping it together?

Secondly, with external bottom brackets (or press-fit), how is bearing preload managed for self-extracting cranks? Seems to me that once it's on, it's on, it won't go on any more! if the spacing between the cranks is off just a bit, I don't see how it gets adjusted (maybe spring washers?)

Designs that use self-extractors and either a splined or lobed interface between the crank and spindle all feature a press fit at that interface to prevent any small movement that would otherwise cause damage. Otherwise you wouldn't need a self-extractor; remove the bolt and your crank would fall off. They're also reliant on the crank bolt being present and torqued properly to prevent them from coming loose.

Preload is managed on such cranks in a couple different ways. A wavy washer or an elastomer can be used to establish preload automatically. These have have the downside that BB width tolerance has a direct impact on how frictiony or loose the bearings end up being. The SRAM/Truvativ GXP design pinches the left bearing and allows the spindle to float through the right one. And then there are the cranks with adjustable preload rings, which are good at allowing you to always have a perfect adjustment but by the same token add a maintenance point.


Which removal tool for Rotor PF4624 I have the Rotor PF4624 386 Road Bottom Bracket (C04-026-01010-0) in my Open U.P. Frame (BB386EVO pressfit 86.5x46mm BB shell) and need to remove it to install a Di2. I have read that some people pressed out the bearings only and ran in some trouble afterwards since they used the wrong removing tool. So I want to be on the save side from the start but do not know which removal tool I should use.
Can anyome help me here?
There is a side question on this. Is it possible to install the old bottom bracket or is that not recommandable?

Your options can be summarised as tools that push, or tools that pull.
A normal bearing puller can be difficult to use without damaging the paint on the bottom bracket shell.
Park offers this tool for use with BBs that have a 22-24mm shaft diameter:
https://www.parktool.com/product/press-fit-bottom-bracket-bearing-tool-set-bbt-90-3
Other brands may have similar products.
I don't have any bikes with pushfit BBs so I can't comment on reusing a BB removed with such a tool.


How to replace derailleur cable housing? My derailleur cable housing (sheath) has exploded:

I bought a new sheath of the exact same length:

PROBLEM: Now I realize that unlike brake cables that are like []------, derailleur cables seem to be like []-------[].

QUESTION: How can I put the cable inside the housing? I don't have many tools, just screwdrivers, Allen keys and a few common others.

The "double end" accommodates a variety of attachments. The idea is that you cut off the end that doesn't match your setup. Then the cable looks like a brake cable :-)

So, what you should do it to remove the old cable and match the end to the new cable. Then cut off the end that you don't need (cut near the "wrong" end so that you preserve the cable length). Now you'll be able to thread the cable through the housing (sheath) and make your repair.

When you remove the old cable pay attention to how the ends are attached. You'll put it back the same way.

If you don't have / can't afford the investment in a "proper" shearing type cable cutter mentioned in the comment, you will improve your chances is you cut at the very end of the cable up against the end you are removing. The metal that formed the end may help to support the cable strands and create a cleaner cut. If the end does get mangled, try to reform the end of the cable by twisting the strands back into place. Here's an example of the kind of cable cutter you're looking for (in this case a Park Tool CN-10).


Cleats for Shimano PD 1056 pedals I've bought an old racing bike with Shimano PD 1056 pedals installed and I am in need to buy cleats compatible with these. G****e search for "PD 1056 cleats" reveal SHIMANO SM-SH11 SPD-SL cleats, but I could not find the pedals in any compatibility list für these cleats.

Are these both compatible or is there a better suggestion?

Here are some photos of the pedals:

These pedals will take the old style Look Delta cleats, NOT the Keo-type. The cleats are readily available from Look retailers. You can have them with the same specifications as the Keo cleats, in black, grey and red with 0°, 3° and 6° sideways free rotation.

Be aware though that the pedals have built-in sideways freedom of movement, toggled by the slotted screw at the rear so that it's not a good idea to buy the grey or red type. Probably too much of the good!


How important is it to re-space my rear hub? I just bought new wheels for an older Schwinn frame. I don't know the date it was made, but it's a steel frame and as built it had stem shifters and a cup-and-cone bottom bracket, etc. Probably from some time in the 80s, I estimate.

The spacing between the rear dropouts on the frame itself is 130mm; the new rear wheel and hub arrived spaced to 120mm. It's a flip flop hub with a solid axle (no quick release). I am able to get the hub to fit snugly between the dropouts just by tightening the axle nuts, since the steel frame will bend to make up that 5mm on each side pretty easily.

Is this a safe setup? Or do I need to add spacers to the hub to fit the 130mm frame without any bending?

No, that much of a spacing difference is generally a bad idea even with steel because of the increased stress it causes in the dropout area, which may cause or contribute to failure of the frame in the dropout area over time.

How bad it is exactly on a given frame is difficult to pin down. But it's observably true that the right rear dropout is a common failure point from fatigue on heavily ridden bikes where everything else is holding up well. The static stress that gets created from having the frame squeezed down can only add to that.

Presuming it's steel, just respace it to 120, and then re-align the dropouts afterward. A side benefit is that you get to align the rear end at the same time you respace it, so it can be perfect on both fronts.

Having the spacing and dropout alignment be right will also make tensioning the chain during wheel re-installation be a much smoother process.


Long Distance Navigation I'm looking for what's available in terms of navigation for long distance rides.

I will hopefully be doing some cycling around Europe in the coming summer, and would like to be able to know that I'm not going to get lost.

I'm open to all solutions, be it GPS navigation or strapping a map and compass to my handlebars!

What are the pros and cons of my options and what is most workable?

I spent all last summer biking around Ireland, France, Italy (a bit), and Germany with my wife.  We went with map and compass to avoid being dependent on a battery to not get lost.

Map Scale.  In general, you need at least 1:250k map scale in my opinion.  More detailed (i.e., 1:200k or less) is nice, but you can end up buying/schlepping a lot of maps that way.

Ireland. We used a 1:350k Rough Guide map that was just not quite detailed enough for bike touring.

France. Go with Michelin 1:250k regional maps -- super accurate.

Swizerland. Use the SwissTrails pdfs (a tour operator, but they are good), and follow the signs.  Most amazing signage in Europe.

Germany. The ADFC/BVA bike maps. Also has crazy lots of signs, but the map really helps.

Italy.  We used Michelin again but were disappointed in the accuracy, particularly compared to Michelin's France maps -- never found a good alternative though (we left Italy after a week since it was just too hot to tour in July).

Map Holders.  See "Map During Touring?" on this site for info on map holders.

Compass.  Definitely strap a mini-compass to your handlebars.  Invaluable.

Camera.  I didn't really think of a camera as a navigation device before this last trip, but it is really useful to take pictures of maps. Many European towns have maps posted on the outskirts, and it can be helpful to take a picture to refer to later.  We would have been lost in a park in Italy had we not taken a picture of the trail map on the way in. Similarly, you can save on printing costs at an internet cafe by taking pictures of Google Maps at various zoom levels. I wouldn't plan a whole trip based on camera maps, but it is really nice to supplement.  Just make sure you have extra batteries, that you know how to use the pan and zoom on your camera, so you can look at the details of a map-picture.


What features should I look for when buying bib tights? I want to buy a new set of bib tights for cold weather biking, but there are many choices and variations and huge variations in price. What qualities should I look for - e.g. fabric, padded insert, straps, back material, water resistance.

Some have a section of material on the back but would these models only be for more extreme cold weather riding?

I consider cold to be 5 degrees celcius to -5. Extreme cold -5 and lower. Majority of my cold weather riding is not extreme.

This is a somewhat subjective topic as everyone has their own personal preferences.

But for me (a skinny 30 something riding in Scotland where winter is typically -5 to +5°C):

Fabric: Generally a thick 'roubaix' style brushed lycra for warmth.  Windproof fabrics tend to be less flexible/comfortable and I would only use them in extreme cold weather.

Padded: No. You can wear your existing shorts under non padded tights.  If they have their own pad, they need to be washed every use, without a pad the tights can be re-worn after some rides.

Straps: Personal preference.  Some prefer the higher waistline and extra material for warmth.  Personally I prefer easier natural breaks as riding in very cold conditions makes them a more regular occurrence.

Water resistance: I find DWR treatment an amazingly good feature on tights, with splashes from puddles just bouncing off, keeping you much drier and warmer.  Softshell type materials (which are also usually coated) will be even more water resistant, but have their own drawbacks (covered above).


What is the equivalent for Shimano Roller Brake grease? I'd like to regrease my roller brakes, because it started to squeak. There is dedicated Shimano Roller Brake grease available, but I'm curious what kind of grease it is really like, what it is made from and if there is any good equivalend, substitute or something with similar composition for general usage.
I know that this grease is supposed to be high-temperature-resistant and that's the main requirement, but has it another characteristics, that has to be taken into account?

Just as a confirmation on the comments above, I found a post on a separate forum definitely recommending to use the specific manufacturer grease, with a couple of the following points (Cited here for possible link decay):
For the grease itself-

Since my original post I have found some good information about lubricating the Shimano roller brakes.

Definitely use the roller brake grease available from Shimano (although it is fairly expensive), this is a demanding application due to the heat and forces generated within the brake and the lubricant is very high quality - it is a molybdenum disulphide based grease, and to me looked denser than what one usually finds say in automotive moly greases. Also it is lower viscosity so the brake will not drag and the grease can get into the braking surfaces more readily.

For application (And which indicates the poster spoke to someone at Shimano):

Very important to follow the instructions that come with the grease - main point is to insert the grease tube nozzle at least 12mm into the hole otherwise the grease will not reach the actual braking surface. If you look carefully you can see the cooling disc move a little when the nozzle is in far enough as it will push against it; come back just slightly from this position so the grease flows easily.

Shimano said you cannot really over do the grease as the excess will simply squeeze out and collect under the side cover. I was fortunate enough to be able to get an old brake and dismantle it - it looked to me like a rounded teaspoon or so of grease (say 10+mL) would be fine and my brake went well with this. Remember to rotate the wheel a bit while putting in the grease so it distributes evenly around inside the brake. Note that Shimano forbid dismantling of these brakes, and having done so with the old one I would say there is very little reason to anyway, and parts cannot be bought individually for repairs - still it was very interesting to see how it actually worked. The rollers (6) are not actually the brake, but push out three metal crescents that bind against the braking "drum" that is bonded to the centre of the cooling disc.

There are a couple of other points in the link, mostly just some tips about making application a bit easier. I could find absolutely nothing on a recommended substitute, which leads me to believe that the comments are correct, it's not worth it to try and find a substitute.


Back wheel lock up, when got off wheel would move side to side I have a 29 inch Iron-Horse/Sunday 24 speed. My back wheel locked up, when I got off the wheel would move side to side.

I thought I lost bearings, took my freewheel apart and clean. Doesn't look like I lost any bearings, but not sure.

If the wheel wobbles in the frame (and the QR or through axle is tight), or with the wheel out you can wobble the axle in the hub: at least one of the bearings has a problem, or perhaps the axle broke or the hub shell has failed. If you have a serviceable cup and cone bearing hub, one of the cones may simply have come loose.

The way forward depends on what kind of hub you have. Without more info on the specifics of you hub we can't provide further advice.


Smartphone app that alerts when a rider is left behind I belong to a few off-road bicycle in groups. We ride during the day and at night.
Does anyone know of a smart phone app that would alert the bicycling group leader when one of the group is left behind, meaning when they are more than certain distance far away?

I don't believe there's such an app, so here's an app-assisted approach.
It doesn't alert but both clubs I ride with have used WhatsApp location sharing to meet up on the road. Other location-sharing tools exist too. If you use a back marker (a role I've often taken in the slower of my clubs, being fairly strong and well equipped, with maps and a loud voice), their job is to stay with the slowest rider and they could share their location with the leader. With big groups, designating a back marker (or pair of back markers) is worthwhile. They should have the route and good lights if darkness is an issue.
You could run location sharing all the time, or you could rely on starting it if you're dropped - this would be more suited to mechanicals when you're stopping anyway, as I can't really recommend that much fiddling with your phone while riding, even with it clamped to the bars. Setting up a group for the ride (or series of regular rides) would be necessary.
In fact the messaging alone is useful - I've received a few "you ok ChrisH?" messages when I've been dropped from a faster group for reasons including cramp, a last minute reroute, and of course simple slowness. These are best if the leader says where the group is waiting (assuming they are) as you don't want to stop to reply, then come round a bend and see them.
Location sharing relies on a data signal, which is fine for local road rides, or my nearest trail centre, but not much use for wilderness cross-country. Without it there may be push-to-talk radio apps that use a WiFi signal. That should give you enough range. Whether any can display location is another matter.
Update October 2020: If the group (or more likely a leader and back-marker) all use IpBike on their phones as bike computers, IpPeloton (under development) shares the riders' stats across the group - but only if they're in range.  This would work for a tight group, but not for a loose one.  You'd need to test what's shown when someone drops off, and how far away they have to get. The inherent range limits of this technology mean it's probably not the way to go; either a proper data connection or a WiFi network between riders would be necessary.
Further evidence for the unsuitability of Bluetooth Low Energy is given in this  preprint which (in the context of contact tracing) discusses proximity sensing using Bluetooth beacon signals and only being able to the read signal when <10m from the other device.


Can someone help me to identify this bike model It's a "Focus" road bike, from 2013 or 2014 (I think).
Can someone tell me the exact model ?
Thanks a lot !

Based on the current lineup of 2016, I'd guess its a Cayo, because their other models have radially spoked front wheels.  However that could have changed in the last three years.

http://www.focus-bikes.com/us/en/bikes/2016/road/performance-cayo-al.html

Their website was the top match on google for "focus road bike"


How to correctly identify bearing cones for axles, to find replacements? The cones of a bicycle front axle are quite pitted, and I decided to replace them. The Axle still is fine, I'd only need to replace the cones.
The problem I'm having is finding replacement cones. I'm not sure what sort of data I need to search for them.
So far I tried with the axle diameter (9.5mm or "Fg9.5", when measured on the thread), the length (11.75mm) and the OD (15.5mm) of the cone. The cone wrench needed for those cones is 12mm, I also tried searching using that, but I'm having very little luck. It seems most shops selling cones (including sellers on Ebay) refer to the bicycle brand or model name. However, the bicycle in question is an old, German ladies bike, around 20 years old.
I can't find any markings on the cones, and cones don't seem to be sold for a particular axle type (mine's a Fg9.5 x 136mm, but that one is nearly impossible to find).
I'm not sure I'm using the right combination of data to look for them, or I'm looking completely in the wrong way. Since cones are one of parts that wear quite quickly, I'd imagine there must be replacements but I'm having a really hard time to find them.

I find it rather difficult to get cones by themselves in Germany. It is much easier to get an entire replacement axle with cones. Often enough I found the whole assembly to cost less than an individual identical cone.
The good thing about cup-and-cone hub bearings is that there are only two ball sizes. The front always has 4,762 mm (3/16 inch) balls. That means also the races on the cones will fit.
When the outer diametre fits as well and the cones have about the same length a different axle with their cones might do.


Rear wheel doesn't turn with cassette I just got a used mountain bike and on my first trip my rear wheel stopped turning with the cassette. When I pedal it turns the cassette and the gears still change smoothly but it doesnt turn the rear wheel anymore. What can it be? How can I fix this?

Really hard to say without knowing what hub you're running. Most likely the pawls failed inside the cassette body. The pawls and springs are the mechanism which allow cassette to spin freely independent of the wheel (like when you coast or spin the cranks backward). When forward pressure is applied to the cassette the pawls and springs engage and thus move the rear wheel. Fixing them can be a very simple process involving nothing more than a couple of allen wrenches or a rather more involved process requiring replacement of the cassette body. Really depends on the specific hub involved.


Which Crank Brothers cleat do I need? I ride these pedals:

which came with these cleats:

Now I see that Crank Brothers are selling their "Premium" cleat:

I'm ready to replace my cleats. Is the premium cleat compatible with my pedal, or do I need to stick to the earlier style? Do the 'wings' on the original cleat offer something that I need?

To directly answer your question, yes, the Crank Bros Premium Cleat is the one you want.

Per their webiste -  compatibility: eggbeater, candy, smarty, acid, mallet ( http://www.crankbrothers.com/accessories_premium_cleat.php )

Some good FAQ on these from Crank Bros:
http://www.crankbrothers.com/support/faq_candy.php


Disc brake producing noise after a crash After little crash I'm hearing strange knife-like sounds from my disk brakes, but the wheel and brakes doesn't look damaged. What should I do?

An unaligned caliper (the unit that sits over the disc) is far more likely than a bent rotor. It's more exposed and susceptible to being knocked.

You should first try to realign your disc brake caliper as this will quickly show if it is a rotor straightness or caliper alignment issue. This is a simple job and will only require the correct sized hex wrench.

Loosen the bolts that secure the caliper to the frame or fork. If an adapter is used (generally on rear) loosen the bolts that hold the caliper to the adapter.
Lift the wheel off the ground.
Spin the wheel and while it's spinning apply the brake.
Let go of the brake and spin the wheel again. Apply the brake and keep it applied.
With the brake lever still in re tighten the caliper.
Spin the wheel again if it still rubs you may have a slightly bent rotor.


Tensioning rear wheel? Tensioning a front wheel is - at least in theory - very simple: Go around and tighten each nipple by e.g. a quarter turn. Then re-adjust trueness if necessary.

I guess if I'd do the same to a typical road rear wheel (with freehub / 10 speed cassette), it would loose the 'dishing'. Is there a rule-of-thumb for this, e.g. something like "3/8 turns on the drive side, 1/4 turns on the other"?

If you are just tightening it up, you should not have a problem keeping the same rules as the front. When you are assembling the when is when the hard part comes, as far as keeping the hub aligned properly.

I wouldn't suggest doing a 1/4 turn all the way around on either wheel. The spokes all come lose at different rates and for different reasons. My suggestion is to go through and get all the spokes evenly snug, barely past loose. If there are snug ones don't turn it at all, if they are loose, turn it 3 or 4 full times if it needs it, just get them all roughly even, but no need to loosen any if they feel too tight, that is for later.

Once you have them all barely snug, go through another time and tighten them up to proper spec tension. In the bike shop we had a torque wrench for the nipples, but if you don't have one, just tighten it up to what feels right. They don't need to be nearly as tight as your axle nuts, they will strip pretty easy if you over tighten them.

If you want to true them, it is best to use a stand, but you can tape a stick to the forks, or just use the breaks as a rough guide. Tighten the 4 spokes opposite the wobble. Just don't go over board, you could "egg" your wheel.


stop air leak when disconnecting inflator from presta valve Presta novice question. When removing the adaptor and quickly screwing the inside core down, air escapes. I've changed from a short Zefal pump to using a compressor. The tire says 50-60 PSI, but by the time it is disconnected I lose a lot of air. Do I go with the tire PSI or presta recs which are like 80-100? Thanks!

In my experience there is always some air loss when you remove the pump from a Presta valve, but that air is lost from the pump side of the valve.

It's easier to see with a floor pump, since there's the hose to hold air. In a floor pump there's a check valve is at the pump end of that hose, and that will hold the air in the hose at high pressure even after you let go of the pump handle. That high pressure air escapes when you release the valve.

With a handheld pump there should be much less air released when you pull it off, because there's probably no check valve - the path from the pump chamber to the tyre is so short it's not necessary. Because it's so short there's not a lot of volume to hold high pressure air. Even if you release the pump from the valve while holding the pump handle in, you'll hear a little "phut" as the air escapes rather than the long "pssshhh" from a floor pump. But usually you let go of the handle, it gets pushed out a little until there's not enough air pressure to push it further, and when you pop the handheld pump off the valve you don't hear anything.


Grease for hub bearings? (NLGI grade) I know this question has been asked many times on here and other bike forums.
I'm struggling to find a proper answer.

The NLGI basically refers to the thickness of a grease.

I have some lithium based grease on hand and the NLGI grade is 3 (consistency of vegetable shortening), so thicker than grade 2 (consistency of peanut butter).

Would a grade 3 grease be fine to use for bicycle hubs?

Thank you for any help!

NLGI 3 is harder than optimal. Shouldn't create a problem, but NLGI 2 should provide better lubrication and still be hard enough to resist being pushed and washed out of the bearings (all else being equal).

Hubs are spinning when used, and at relatively low speed, so no need to worry about lubricant starvation. The harder the grease and the more viscous the base oil, the more chance of lubricant starvation, but, like said, since bicycle hubs see very low rotating speeds (and loads for that matter), the differences are mostly "academic" in my knowledge and experience.


What is this aluminum plate that started rattling inside my Ksyrium rims? During my last ride I noticed a rattle coming from the rear wheel at slow speeds.

I removed the wheel but shaking and rotating it did no good. After some head scratching I thought about inserting some plastic tubing inside it to isolate where the moving thing is. Turns out there is an aluminum plate that slides near where the rim is welded (see pic).

I drilled a small hole into the loose part, thinking that maybe I can pull it towards the nipple insertion hole (the large hole in the pic, sorry but that's the best I could focus) so I can drill it to pieces. But it won't budge past that point. Only thing I can do is lock it into place with polyurethane foam.

But what is it and why did it start moving now?

Edit: I contacted Mavic and they confirmed that it's a non-structural part that holds the ends together during welding. IMO polyurethane foam is the best bet as it will expand and hold it in place.

2nd edit: FWIW, Mavic replied again with suggestions for fixes. They recommended the center punch method or glue. The warned against using foam as it can create a "heavy spot" that causes wheel imbalance. IME foam is very light, way lighter that the valve stem anyway and it's guaranteed to work so I'll go this way.

This is a more detailed answer. I cautiously don't agree with Chris that the OP needs to stop riding the wheel, but it does depend on how the rim is constructed. Basically, the aluminum piece is a sleeve of some sort. The sleeves are structural elements in some but not all rims. I believe it is not a structural element in this rim, which the OP described as a 2008 Mavic Ksyrium Equipe. I shall explain why, but this requires a review of how rims are constructed and joined.

A review on alloy rim construction methods

There are 3 ways to join rims. Astral Cycles is a rim and wheel manufacturer in the US, and they explain:

  A: To understand why the joint matters, it is important to know the
  process. We roll our extrusion into a helix that will eventually
  become two rims. After a rim is rolled, it is cut and then requires
  the two faces from the cut to be joined together. There are three main
  ways to join a rim: pinned, welding and sleeve.

  Pinned: Only the cheapest of rims are pinned. Pinned uses two steel
  dowel pins jammed into formed or extruded holes in the rim to hold the
  rim together. Pinning only holds the mating rim faces at the two pins
  so the brake track and spoke bed of the rim have a lot of flexibility
  to move relative to each other. This is why some cheaper rims tick in
  the brakes at the seam.

  Welding: This came to the forefront to replace pinning on nicer rims
  about 30 years ago and was a big improvement. Welding can create a
  nice, finished looking joint but it has some tradeoffs. The material
  in a rim is heat treated to increase the strength of the material.
  Without this heat treatment step, aluminum is not strong enough to be
  a bike rim. The flash welding process generates an enormous level of
  heat at the joint area creating a “heat affected zone”. This heat
  affected zone degrades the heat treatment of the material surrounding
  the joint making the material at the joint weaker than the material
  everywhere else in the rim. This is not to say it doesn’t work, just
  that in our experience this unnecessarily makes the joint the weakest
  part of the rim. We have full welding capability in our Oregon
  facility, but with all of our experience, we have decided to sleeve
  join our rims.

  Sleeve: Sleeve joining uses a form fitted sleeve in the exact shape of
  the inner cavity of the rim to span the joint. It is about 2.5” long
  and weighs typically 4-5g. In our process, this sleeve is a press fit
  - meaning it is incredibly tightly fitted and requires a specialized press to insert. We use epoxy as an insulator to minimize the
  potential for any noise but the epoxy is not a structural part of the
  joint. What we like about this process is that the sleeve effectively
  doubles the wall thickness in the immediate area of the joint making
  it the strongest part of the rim and it does not affect the heat
  treatment of the material. We then machine the brake tracks after
  joining so the brake track is completely smooth.

One further point: at least some welded rims are held together by a small sleeve during the welding process. After welding, the sleeve plays no structural role, i.e. it does nothing to hold the rim together. The sleeve also acts as a heat sink during welding. This may reduce the probability that the rim warps, and it may mean that the welding process doesn't affect the rim's heat treatment as much.

So, what went wrong here?

This non-structural sleeve can sometimes come loose. This link from Wheelworks, a New Zealand company, documents this assertion. It names Pacenti and Stans rims. I have personally had this happen on a Pacenti SL23 rim, as have a few other cyclists (the link provides one example).

I believe Mavic Ksyriums are welded rims. If the wheel has a sticker saying "SUP" anywhere, this means it will be welded; the Fitwerks link documents that SUP is a standard Mavic acronym referring to welded rims. Additionally, I have found several links identifying rattles from the sleeves in Mavic wheels, including the Ksyrium Equipe of the late 2000s / early 2010s. The links seem to corroborate that many Mavic rims were welded with a non-structural joining sleeve.

I believe the original poster could epoxy the non-structural sleeve back into place. The Wheelworks site linked previously described one way to do this: drill two small holes into the rim bed straddling the sleeve, inject epoxy through the holes, then put the rim sleeve-side down and let the epoxy cure. This does seem like it could weaken the rim, and I am a bit uncertain about this advice.

In any case, the sleeve in the question above is more accessible. It does seem like the OP could put some epoxy between it and the rim bed, then slide the sleeve back and wait for the epoxy to cure. In some cases, simply adding lubricant has solved the issue; this did the trick on my Pacenti SL23 rims, and it worked for several other consumers. However, the sleeve was in my rim not quite as loose as on the OP's Mavic rim. I could not physically locate it, and I believe it was just rattling in place.

If I am wrong and that rim actually has sleeved construction, then stop riding it immediately. This means a structural sleeve, i.e. the rim isn't welded together, and it's held together by the sleeve plus spoke tension. I'd urge you to verify the rim construction method. If anyone knows that the 2008 Ksyrium Equipe actually is joined by sleeved construction, please comment.

Regarding Astral's assertions about sleeved vs. welded rims, my impression is that most current performance aluminum rims are welded. Thus, the relative advantages between welded and sleeved rims are probably up for debate. I don't think consumers should categorically avoid either welded or sleeved rims. Having the non-structural sleeve come loose should not be a common event, either.


How rideable is the Long Island Expressway service road? I am new to the NYC region, and just recently found out that the LIE even has service roads!  I was wondering how rideable the service roads are.

I.e. Can you actually get across the various interchanges on a bike?  (Clearly if cars are expected to merge back onto the highway to ride across the interchange then that is a problem on a bike.  Though I would be willing if the cops don't care...).

As part of this, I am curious how far the service road extends, that it is possible to ride.  If there are known areas with issues, are there workarounds known?

I would avoid the LIE Service Road At all costs during rush hour.

A couple of friends of mine have actually been issued tickets for riding on the service road. It seems to be illegal according to the New York State Department of Transportation.

Additionally many of the bicycle deaths on Long Island have occurred on the service road. We rode the service roads in a pack during rush hour cars with driving very fast and there is very little no shoulder in most areas.

It can be really treacherous during rush hour which typically starts at 2:30 p.m. and lasts until 7 p.m.


Hydraulic disk brakes starts braking after pulling the half of the lever, how can I solve this problem with the brakes? I have upgraded from v brake which starts braking immediately after pulling the brake lever, but in my new bike the brakes starts much later after pulling the lever. What problem it may have? I am using a Tektro branded brakes.

I think it depends on pad adjustment and most hydraulics have some kind of auto adjustment, also following pads' wearing - small "springs" between the pads return them to the initial position. Cable driven disc brakes can be adjusted at the caliper for tighter fit.
You'll probably never be able to start braking immediately. It needs some play, otherwise it would always touch the disks.
Though wiht hydraulics you should also check if you have enough oil/brake fluid in the lines, without air in it. That can also cause a loose, weak braking. It's probably done best by a professional.


Alfine crank 1x9 setup, spacer issue I'm currently rebuilding a 1992 Kona Cindercone as a 1x9 commuter.
The rear spacing is 135mm and the bottom bracket shell is 68mm.

I've mounted a alfine crank on it and remove the spacer that what installed on the drive side of the crank and put it on the non drive side on the crank.

The chainline looks okay and both crank arms seem to be at the same distance with the chain stay. However I now have that massive spacer in between my crank arm and BB cup and I'm sure this is plain wrong.

I also have no experience with hollowtech cranks.

Here are some picture to illustrate my problem:

So what am I doing wrong here?
Thanks

I found the solution!

I've bought an alfine crankset with inner + outer chainring (FC-S501 GCx2) instead of of an alfine crankset with only the outer chainring (FC-S501 GCx1).

The problem being that the FC-S501 GCx2 is designed with a 49.2mm chainline and the FC-S501 GCx1 with a 42.7mm chainline.


Can’t find name of a product used in carbon fiber repairs Several years ago, I watched a youtube tutorial about repairing carbon fiber. I can’t find that video now, but one of the first steps, before applying sheets of cabon fiber, the guy used a compound that was a mix of carbon and epoxy applied down inside a crack, where the sheets couldn’t be forced in. It was kind of an extra step just to maximize strength as much as possible. It was a charcoal color, and it was sanded smooth before applying carbon sheets. I can’t figure out what it was called, but I need some. I guess it’s possible the guy made it himself...

Anyone know what it’s called?

I found the video, and it turns out my memory was off. It’s a graphite powder mixed with epoxy. He doesn’t explain why he used graphite, but that layer of resin was only to prevent air leakage from inside the tubing during the vacuum stage, and probably also to help the carbon sheets lay flat. Perhaps the graphite was added to make the resin more sandable? In any case, it wasn’t a carbon mixture, and it does not provide strength to the repair.

I would be interested in hearing if anyone has knowledge of such a product.


Carbon Fiber Wheel Replacement I discovered a gaping hole about 1" x 3/8" in my carbon fiber rear rim, at a spoke.
The rim is a Fulcrum S-19 Racing (22.5x622x28), that I ride on about 100 miles a week,
so I imagine this rim is kaput.
The rims are about 4 years old and came on the Specialized Tarmac 2017 when I bought the bike.
Right now I am using the bike for just regular road cycling, no racing, so I don't need the bike to be light and have carbon fiber.
#1 Are there any issues with switching both front and rear rims out for less expensive alloy rims?
#2 Can you just switch out one rim, the rear, and it change to alloy, and leave the other, the front rim, carbon fiber?
#3 Just to verify- the damaged rim is unfit for further use?
#4 Any point in installing the used rear cassette on a new alloy rim?
Thanks for any feedback - Street Roller

Whatever material that rim is, it's completely unfit for further use. The area around the spoke has completely pulled out from the rest of the rim. The rim's structural integrity is in doubt, plus it is also out of true.
In principle, there shouldn't be any objective issue running one alloy and one carbon rim, provided you changed the brake pads for the new alloy rim. The brake pads for carbon and aluminum rims are made of different materials. You may not see effective braking using a carbon pad on an aluminum rim. Otherwise, it's mainly an aesthetic drawback to have mismatched rims.
For your stated use case, alloy rims will provide better braking, especially in the wet, than carbon. Carbon rim brake rims are expensive and slightly higher-maintenance toys. There is nothing objectively and intrinsically wrong with liking expensive toys, however. Also, I don't believe this failure mode is common on quality aluminum or carbon rims. For carbon rim brake rims, the higher-maintenance bit mainly amounts to using different brake pads, plus you should probably be more conscientious about cleaning the rim surface after wet rides (remove grit, reduce wear), plus your braking in wet rides will be poorer, plus on extended descents (which not all of us do) you need to be conscientious about braking in pulses (don't drag the brakes, this can melt the resin in the rims after too long).
For the cassette, if you consistently changed your chain before it got too worn, the cassette is likely to still be quite usable. If it is worn, then you should recycle it, as it is likely to cause wear to a new chain. Generally, chain checkers are pretty cheap, and I do recommend that most cyclists get one. However, your local bike shop will generally check for you. The issue with cassette wear is that it is hard to assess visually unless the cassette is very obviously worn (and if it's that worn, it's too much too late, and a new chain would skip on the cassette anyway). Basically, if a new chain skips on the cassette, replace the cassette.
In general, it's often possible to acquire a new rim and rebuild the wheel. In addition, some wheel companies may offer a crash/damage discount on parts, even if the wheel is out of its warranty period or if the damage was clearly the user's fault. It doesn't hurt to ask Fulcrum, although they may not do this. (NB: this does look like a warranty case if you're still in warranty, and I'd suggest asking the store that sold you the bike about this if you think you might be in the warranty period.) Outside of replacing with OEM parts, you or your local bike shop could usually lace an aftermarket rims and spokes to the hub if you were not able or willing to source a replacement rim from Fulcrum (which might be relatively costly). However, some Fulcrum wheels use an unusual spoke arrangement where there are two drive-side spokes for every one on the non-drive. If there are 21 spokes on the rear hub, then standard aftermarket rims are not made in this drilling and you would need a Fulcrum replacement. For at least some Fulcrum wheels, there are no spoke holes in the rim bed, and a wheel builder may need to use special tools to insert the nipples. It's possible that your local bike store may be unable to handle this on their own. If either of those are the case, that might push you in favor of trying to source a replacement wheel or set of wheels, especially considering the rim brake market is probably relatively weak.


What's the purpose of this part of Topeak Hexus II multitool? What is the purpose of this part of my Topeak Hexus II tool?

I can't find anything in the manual.

This is the other clip end of the tire lever.  The tire lever with the clip is intended to go in first and hold the lever in place (by clipping onto a spoke) while you use the other lever (with your hand) to go around the rim and break the bead.

If you check the "Using Tire Levers" section of the manual, you can see the clip being used to secure the first lever to a spoke.


Alternative tools for servicing a Fox fork 2016+ Official tools are too expensive. I mean lower leg removal, seal driver and seal extractor tools. Forks with new seals from 2016 onwards. Which alternative tools do you use?

My fork: 2017 Fox 32 Float SC Performance 29", 100mm Travel, FIT4 Damper, Remote Lockout, Boost 15x110 KaBolt, Tapered.

UPDATE: Pictures of seal driver and lower leg removal tool. Taken from here.

If you just need to service your own fork occasionally, you don't need to buy specialized tools.

To remove the seals you can use an large wrench/spanner, be careful not to scratch the inside of the tubes:

Images are taken from this guide

Inserting the new seals can be done with a socket of the right size:

You don't need any special tools to remove the lower legs. Unthread the bottom nuts half way, then place the socket over them. Now you can gently tap the socket with a rubber mallet to loosen the lower legs, without hitting the rebound adjuster.


Regina Extra Freewheel or Cassette I have a road bike (Carlton Flyer, 1977) with a regina extra rear cassette. I'm interested in downgearing it (i live on a massive hill) and am trying to identify whether it is a freewheel or cassette and if downgearing is possible - before I start pulling it apart.

Pic

Ideally, I'd like to replace it with the same type, or add an extra ring at the top to give me a climbing gear. Doesn't have indexed shifters so I don't think that would be an issue.

Any help appreciated!

It is a freewheel. You will need the appropriate freewheel tool. The tool typically won't fit without removing the axle. You may also need the correct cone wrenches. This makes it a good time to service the wheels bearings as well. You may want to consult your LBS and compare the cost of having it done versus purchasing the tools you may only use once.


What causes my chain to derail at the rear when I accelerate? I recently bought a beat-up old mountain bike for commuting. I've tried to clean and adjust the derailleurs and everything seems to work well enough in my garage. But when I put heavy weight on the pedals (say, starting across an intersection after a stop light) the rear gear momentarily derails with a crash (or do you say the chain derails?), I flounder for a second, there's another ugly clashing sound, and then things go back to normal.

Is this something that I can adjust my way out of or more likely an indication of a worn-out part?

It sounds like the combination of your chain and cassette / sprocket are at the end of their lives. Examine them for signs of wear.

To check a cassette for wear, look for pointy teeth. A non-worn cassette will have teeth with a fairly flat ends.

A worn cassette will have teeth that have become pointier.

To check your chain for wear, ideally you'd use a chain wear tool to check how much your bushings have been worn away. If you don't have one of these tools, you can kindof tell when a chain is worn out because it will feel like the bushings are a bit loose.

Alternately, a drivetrain generally wears out at around 10000 kms (~6000 miles). You can rack this amount up pretty quickly as a regular commuter.


Should I get a road bike? Last year I started biking again. My current ride is a quite good "cross" bike weighing a bit more than 10kg  (~22lb, I didn't weigh it). Currently I'm doing around 200km (~120 mi) per week, mostly on roads. Now I'm wondering whether a road bike would be beneficial for day-trips or such. I live near the Alps in a hilly area.

Is there a notable benefit from the lower weight of a road bike? (I weigh 80kg, 175lb) Unless it's a really step difference or a I pay a lot for a very light bike I don't expect much benefit, but might I be wrong?
I wonder how notable road bike tires might be, I'm expecting way less resistance. Any way to qualify that?
A road bike handlebar has more ways it can be gripped, which might be comfortable on longer rides.
A road bike looks nicer :-p

Are there more important factors I should consider? I'd certainly keep my current bike for times where I have to carry luggage or want to stay off roads.

It's all about having the right tool for the job. Road and touring bikes are designed for long rides on roads. In contrast, mountain bikes are designed to go off road, and hybrids are designed mostly for casual riding. If you're doing 200 km per week, you're serious enough about cycling to notice a serious difference when you switch to a road bike.

I recently made a similar switch. I was riding a mountain bike, which I used for commuting, off-road trails, and road rides. I eventually found that I was only spending about 10% of my riding off-road. I considered switching to thin slick tires, but it was obvious to me that I also needed more hand placement options, a more aggressive riding position, a higher maximum gear, and lighter weight. In other words, I needed a road bike. When I sold my mountain bike and got a road bike, I instantly noticed a 2 to 5 kph speed improvement for the same effort.

Since you're considering switching from a cyclocross bike to a road bike, you should expect a less dramatic change, but if you feel like you're losing out from using the wrong tool for the job, you might as well try a road bike. You could at least rent one for a day and see how it feels. Alternatively, you could consider switching just the handlebars and tires on your current bike, since it sounds like you already have a light-weight frame.


Fix a wobbly Shimano freehub? I have a brand new Shimano Ultegra WH-6800 rear wheel. The freehub has about 2mm of play in it. I can feel the play without the cassette installed by grabbing the freehub body and moving it. It moves side to side and a little less in and out.

I installed a cassette (brand new Shimano Ultegra CS-6700 10spd) and put the wheel on the bike (only in a stand) but it makes some awful noises when pedaling and shifting is a mess. If I look at the cassette from the back it is wobbling all over the place.

Should I return the wheel or is this something that can be fixed by disassembling the hub?

If its brand new and under warranty, don't mess around with it... take it back.

Your freehub should have pretty much no discernible play, and adding a cassette on top just makes it look worse.

As for fixing the freehub yourself, I don't know because I've not yet had one that needs repair.


Has anyone ever used the Spiderflex seat on a roadbike? I use a spiderflex seat on my mountain bike, and I would like to use this on a road bike.  Has anyone ever done this, or something similar?

I am 5'10" and 165 lbs (reasonably fit).

Yes, I know the 'the saddle horn is used for steering.....'  - but the spiderflex on my MTB annihilates chafing and discomfort. And I do about 20 miles a day on the spiderflex with ZERO - absolute ZERO pain or chafing.

I know I will forfeit cornering and maneuverability without a horn.  Has anyone ever used such a seat successfully on a ROAD BIKE?
Thanks.

From this question and the other regarding clothes, I think that you would be better off showing the bike or bikes you are referring to when using the term "road bike".

Possibly you are not talking of a road bike like this:

Because it would be just a waste of the money invested in weight reduction / aerodynamics to use it in plain clothes and with a beastly saddle.

Now if you refer to something like this:

I would say a saddle like the one pictured is comfy enough for 11 miles, but you can uglify the bike for comfiness sake, police will not fine you. And casual clothes would fit perfectly aestethically.


Issue with PF30 BB on Boost frame - 2-3mm crank arm clearance I have a brand new Titanium Boost 29er hardtail.  The frame uses a PF30 BB and the BB shell is 73mm wide.

I have installed the recommended RaceFace cinch PF30 bottom bracket with a Race face Next SL crank - 175mm arms and 32t single chain-ring.

The problem is that the clearance between the chain stay and the crank arm is next to nothing.  There is no contact yet but I am unable to run the recommended crank boot protector.

The instruction for this BB so not to use any spacers since it 73mm (68mm ones use spacers).

Adding spacers wont help as it does not lengthen the spindle.  I do not see how a Shimano XTR/XT crank will work here either since it has the same Q-factor.

Any other ideas?

RaceFace makes cinch spindles in various lengths. I assume you have a version for 68/73mm bottom brackets. There's also a 100mm bottom bracket spindle option. It will certainly fit, but Q-factor might become too wide for your liking. Theoretically, you can also order a custom length spindle and spacers from some CNC manufacturer.


Clark's skeletal hydraulics issues I know this is an older less expensive brake system so not sure of my best options. The brake lever are quite firm so is there a way I can remove a bit of the hydraulic fluid from the system? I also find them very difficult to maintain alignment with my rotors...would removing a bit of hydraulic fluid put less pressure on the pistons and open the brake pads even the tiniest bit? Any help is greatly appreciated.

I'm reading the question as saying there's too little pad gap and it's causing rub as well as lever travel that seems too tight/short/firm.

The first thing to do with any problem of this nature is to try pushing the pistons back in (after cleaning the outside if needed) and re-adjusting the caliper centering. Pistons that have somehow gotten pushed out too far can cause all the problems you're having. Some good tools to do this are a tire lever or an 8mm box wrench against the piston faces directly, or a degreased cone wrench, table knife, etc against the pads. It can help to slightly lubricate the pistons first with whatever fluid the system uses (DOT 3/4 fluid in this case) after cleaning them, in case drag when passing through the caliper seals is causing retraction issues.

Overfill per se is not usually the problem, although it is possible to overfill a brake using an incorrect bleed block. What usually gets mistaken for overfill is DOT fluid expanding due to absorbing water that makes it past the seals, because it absorbs water out of the air very readily. Most or all DOT fluid brakes seem like they do this to some extent over time, or at least can. (Mineral oil doesn't do this, which is one of its advantages). It's extremely common, for example, that a new bike that's been sitting warehoused halfway through a model year has this symptom when unboxed for assembly. When Juicy 3s were one of the most commonly specced brakes it seemed like half of them had this out of the box.

If you observe that the pistons can't be pushed back in fully on a DOT fluid brake, fluid expansion due to water contamination is the first thing to suspect.

The simple option is to "burp" a little fluid out by removing and putting aside the pads, putting a rag up to the caliper bleed port, slightly opening the port, and resetting the pistons with the port open (again cleaning/lubricating the pistons first as needed). Some fluid will come out, which the rag is there to soak up before it makes a mess. Close the bleed port quickly when you're done of course. This usually works fine for all intents and purposes. You are reducing the boiling point of the brake fluid every time you do this as well as increasing its compressibility, both of which could hypothetically make some kind of meaningful difference at some point, but we're really talking about a very small amount of water. You also shouldn't try this if you're not prepared to bleed the brake in case something goes wrong. I'll add the disclaimer that I haven't actually done this on Clark's brakes, only on many, many Avid/SRAM brakes. Wear gloves and eye protection.

You could also replace all the fluid, which is the safer and technically correct path if water contamination is suspected.


Hybrid Bike tire selection what size tire can install on my bike? I have hybrid bike (gary fisher Tiburon 2006).
It has 700x35C tires on it or if you want to call it 37x622.
I want to install the widest tire possible to ride on semi rough trail.
Today I received my new tires 700x42c but I wasn't impressed with the unnoticeable added width of 7mm as if there is no difference in size.

I have lots of clearance on all the relevant tires and frame to accommodate wider tires. I have about 3/4" on both sides of the front forks and rear frame. Also enough space between the brakes holder and rim. I checked with a bike shop and they advised me that I have enough room for much wider tires.

Please advise the widest tire size I can install on my wheels.

If you have a 42mm tyre, and still have 3/4" of clearance at all possible points, then your maximum size would be 42mm +19mm = 61mm.

Do check the clearance at the chainstays, the seat stays, and the brake bridge.  You imply you have rim brakes, they're often the limiting factor.


How to calculate bike stand-over height using frameset geometry and wheel radius? While it's best to buy through fitting a bike in store, it's not always possible (discussed here).

On some websites, the stand-over height of a bike may not be listed as part of the specifications.

However, simple geometry would dictate that there must be a way to calculate the stand-over height from knowing the frameset's tube lengths and angles, as well as the wheel diameter alone.

Or is there more to consider?

For example, taking the Genesis Day One Disc in the 60 cm variant as an example:

Seat tube (centre-top): 600mm
Effective Top Tube: 575mm
Head Tube: 185mm
Head Angle: 71.5°
Seat Angle: 74°
Chain Stay: 415mm
BB Drop: 64mm

Stem Length: 110mm

H/Bar Width: 44cm

That's more or less OK, but what size are the wheels?

Hubs: KT-SY1F / KT-MX7R 6-Bolt Disc
Rims: Alex XD-Lite Disc 32H
Tires: Continental Cyclocross Race 35c (wire)

I would like to know the standover in order to determine clearance between my crotch and the top tube.

A good approximation can be made using some basic trigonometry and common sense.

I will use WR as wheel radius (i.e. half the wheel diameter) and the numbers refer to the distance indicated in the picture you uploaded.

First of all, the height of the vertical tube (aka the vertical projection of the tube) is just sin(5)*1.

Then the distance between the ground and the bottom bracket is WR - 8.

So, the distance from the ground to the top tube would be H = sin(5)*1 + (WR - 8)


Brake pad on new bike I have just bought a new bike and after fitting the front wheel I've noticed one of the brake pads is not totally on the rim, part on the tyre. How do I adjust it anyone? Also I can't get the noodle fastened back after fitting front wheel

Noodle: the metal pipe that turns a V brake inner cable through 90 or 130 degrees to go to the handlebar brake lever.

To disconnect or reconnect the brake's noodle you would squeeze the end of both brake arms inward toward each other.  This presses both brake pads into the rim.
If you can reach, hold them in place with your secondary hand, and use your dominant hand to install or remove the noodle from the flippy arm bit.
 From https://www.chicagobikeblog.com/blog/2014/2/20/how-do-you-get-the-dang-wheel-out
There is not a lot of slack to do this; it should be a close fit.  The rubber boot just slides out of the way, and when you release the brake arms, they will pull themselves away from the rim (allowing the wheel removal.)
Given that you already have something wrong with the brake setup, it may not be able to get the noodle in/out because of the brake pad being mis-positioned.  Or the wheel may not be installed completely right, also blocking things.
If its a brand new bike, most bike shops offer a ~6 week tuneup/service for new bikes sold.  Check with your supplier.  This is one feature missing if you bought the bike on-line.