Dahon D7HG Handlepost hinge loosens pivot point I have a Dahon Vittese D7 HG, bought in Perú 1 year ago, my handlepost hinge begins to sound like crack , then I supposed that it could be because the friction between steel parts, and adjustment on my handlepost. I had the great idea to put a thinner rubber on the joint press.

Now, I am feeling some movements in my handlepost pivot point (please see photo).
Could it be normal? I dont remember that, because after the rubber, I feel totally silence in my bike.

Please review the following two references as it possibly your D7 may be fall within the questionable Dahon models:

http://www.performancebike.com/images/performance/web/pdfs/Dahon_Folding_recall2009.pdf

and

http://www.thorusa.com/dahon/technical/recall.pdf

(Dahon enthusiasts have a blog as well that may be accessed through the manufacturer's website and is useful for service tips as well.)


Rear rack or similar storage options for child's bike (16" wheels) My 4 year old has taken to riding with abandon, and we're starting to get into summer, where we hope to do some trails together.  I have a rear wheel bike rack which is sufficient for storage of what we might need to take with us, but he's asked me if I can get him a similar rack on his bike.

He has a 16" wheel diameter Schwinn, a bike like you'd find at Target or Walmart but reasonably solid.  Is it a) possible and b) a good idea to put a bike rack on such a small bike?  Do "one size fits all" or "standard" racks fit safely on a small bike?  I tend to think a basket is a less good idea (as it's bigger and affects balance more), but I'm open to that if it's the appropriate solution (certainly was what I had as a child). He's very comfortable riding on flat or moderately even surfaces (grass, for example, is fine, as long as it's not too long), and falls maybe once a mile, never seriously.

He'd likely be attaching a couple of small toys (cars a bit bigger than a matchbox car, but not gigantic) to it, plus I'd probably have him carry one useful thing, but mostly I'm not too concerned about functionality - largely, he wants it because Daddy has it, and I'm okay with that (as long as it's not too expensive).

I'm probably not going to mod something metal, but I'd be open to something plastic-based (I had thought about making something small out of PVC piping, but I'm not sure if that's a great idea).  I've also thought about just attaching a bungee-type cord to the bike and letting him use that, though again the idea here is mostly that he wants to have something like Daddy.

A "doll seat" might be one solution. They're a little cheaper than a decent rack and won't need modification to fit. You might need to work to find one without excessively pink-girl decorations, but I found this one:


Does a bike helmet without chin straps make any sense? Wouldn't any major impact make it fly off the head and not protect you.

Yes.  And no.  It makes some sense in that a helmet should fit snug enough to stay on on its own.  The chin strap's job it to keep the helmet on your head after the initial impact.  Were one to have some condition (a skin condition, stitches on the face or neck, etc) where the chin strap was extremely detrimental, one would be somewhat safer riding with a helmet simply missing the chin strap, than with no helmet at all.

However, barring some obvious condition, or a radical helmet design that doesn't require a strap to stay on after impact, a helmet without a chin strap makes no sense.


Wondering if my Tiagra shifters are fixable? The name plate broke off (left side) during a crash would this be fixable? The lever is now pointing outwards but can still shift gears.

Fixable?  Possibly - but there will be risks, and you need to decide if the risks are worth accepting.

Downsides:

Its your brake lever - and there's a 50% chance its your front brake lever.  The front brake is the most effective brake on our bikes, because it does 90+% of the braking.  Any bending of the lever back into line will stress the metal underneath.  I can't tell what model of shimano, but there's a high chance its an aluminium (aluminum) bar and they take poorly to being flexed.
The nameplate is also a rain cover, keeping moisture and dirt out of the mechanism.  Without that, the shifting mech will get worse over time as dirt collects in the clicking parts.

Personally?  I'd keep riding it as-is (gently!) without attempting to straighten it, and I'd also start searching for a suitable replacement lever on ebay or whatever your local sources of parts are.  This way you can still ride it for now, though I would not recommend long rides or any racing or back-country rides.

If the "feel" changes, if shifting gets bad quickly, or if anything goes wrong, stop and re-evaluate right there.

If the lever broke while being straightened, then you can't ride it till a replacement is found and fitted, and there's less chance of finding a cheap/matching one - you might have to buy new which can be expensive, and you might end up with a mismatched pair of levers, which is super-irritating.

Answer Replace the lever with a known good one.  Used is fine.


Can I use Shimano 105 rear derailleur from 11-speed bike with 10-speed Tiagra shifters? I have a 10-speed 2013 Specialized Allez Elite with Tiagra componentry (and an 11/28 105 cassette) and would like to install my old Shimano 105 rear derailleur in the back to replace the Tiagra one. The 105 rear derailleur came off a 2015 Roubaix which was all-105.
Will this work? I assume the Tiagra shifters' different pull ratios will simply result in the rear derailleur being pulled at... a different ratio. Will this setup run cleanly and shift smoothly? Are the chain widths slightly different between 10 and 11-speed as well? Is this destined to fail?

TLDR: no that won't work. Tiagra 4700 was introduced in 2015 (see here), so your 2013 Allez will have 10 speed Tiagra 4600 series which is not compatible with any 11 speed derailleur.
Shifters pull a certain length of cable per gear, derailleurs have an actuation ratio. Cable pulled x actuation ratio needs to match sprocket spacing. All Shimano road groups up to 10 speed (excluding Tiagra 4700 and GRX RX400 series) used the same derailleur actuation ratio so derailleurs of different 'speeds' could be mixed and matched.
At 11 speeds the actuation ratio changed, so 11 speed derailleurs could not be used with 10 speed shifters and cassettes. The newer 10 speed Tiagra 4700 and GRX RX400 series groups are said to use the 11 speed actuation ratio so an 11 speed derailleur will work with them.
11 speed chains have slightly narrower external plates that 10 speed, so there is the possibility that a 10 speed chain will rub in a 11 speed derailleur cage.


What are important items for a touring first-aid kit? When riding long distances, either solo or with groups of people, it is obviously necessary to carry a first-aid kit in case of a crash or other injury. What are the most important items to pack, while still considering weight or space? What items can be included in 'travel-size', and which items should be 'full-size'? What items should definitely be left at home?

I bring enough to dress small cuts and stop bleeding, at least until 911 could get to me. If you're riding in areas you might not be able to be reached by emergency services, or if you have particular medical issues that need specialty supplies, a kit like this would insufficient.

Bandages/band-aids of a few different sizes
Gauze -- usually a small roll
Tape -- small roll, enough to tape a skinned knee and a little more
Small tube of antibacterial gel (like neosporin) See GaryW's comment, below, liquid may (or may not) be more appropriate
Advil -- I usually have this in my handebar bag anyway
Alcohol wipes -- one or two individually-wrapped

Other things you might consider are snappable heat packs, a knee brace, and something to put on bug bites or poison ivy for rides in the woods. If you're allergic to bee stings, you might bring something for that.


Daily commuting - are dietary supplements recommended? I've been commuting daily (Apart from holidays, illness and some other exceptions) for the past year, riding 12 miles daily (6 miles with 500ft height gain coming in, 6 miles 232ft height gain riding back) on a hybrid.

Recently there have been times when I've been feeling quite run down by the weekend, lacking energy. It could just be a virus doing the rounds, but it made me wonder if there was a specific diet or dietary supplement that would be of benefit to a daily commuteer.

The canonical recommendation is for "a complete and balanced diet". Whatever 'supplements' you might need depend on what your current diet is. The recommendations I've been given (I'm 50 and commute 24 miles/day) from a dietitian are vitamin D (because I live in Canada - I suspect that recommendation is obsolete currently while I'm commuting 2 hours/day in summer) and (based on blood test results) perhaps a bit more iron (I'm vegetarian). Some of the important components to consider, IMO, include water, salt, carbohydrates, and, rest/sleep. In summary, perhaps you should talk with a doctor or dietitian.

If you want to discover what your current diet is (which is presumably one important question before deciding how to supplement it - an alternative might be physical exam, blood tests), I quite recommend DietOrganizer.


Grinding sound from rear wheel I am getting a grinding noise from the rear wheel which has got louder and is causing increasing resistance over the last few weeks (I live in the Netherlands so cycle every day).

The cassette has been taken apart and cleaned in case it was dirt between cogs, this didn't help. From this I am guessing it is bearings? I've been told that if I took it to a bike shop they would just replace the rear wheel which would be very expensive. Was hoping that maybe the bearings could be changed or that its a different problem?

My bike is a Scott Mountain bike with 21 gears.

Thanks so much, any advice would be really welcome as I am a student with little money :(.
Thanks, James

There are two main types of cycle wheel, cup and cone and cartridge bearing.  Cup and cone bearings are fairly easy to service yourself with some simple tools, normal and cup and cone spanners and some grease. Cartridge bearing hubs need more specialist tools, presses to install and drifts to knock the old bearings out.

You can tell which sort you have by looking at the axle, if it's got a nut and a thin lock nut then it's probably cup and cone, google some pictures to see what they look like.

If it is cup and cone then taking it apart (only undo 1 side btw or you'll lose the centre of the axle), cleaning the loose ball bearings you'll find under the cones, then regrease and reassemble may sort the problem; however if its actually as bad as you sugest the ball bearings may need replaced and if the races that the ball bearings sit on are pitted then the wheel may be beyond help. There are lots of videos on the web showing this process.

If it's a cartridge bearing hub then your local shop might be the way to go unless you want to invest in some tools.


Suggestions for winter cycling glasses? I'm looking to get another pair of glasses for winter commuting. I currently use simple ski googles with my snowboard helmet...the problem is they are tinted. Since it's quite dark for the return, i would like to find some clear googles. Also, the temperature is around -15 to -30 degree celsius...I need something to prevent my eyes from crying and freezing or the other way around ;)

any suggestion?

Look for downhill MTB goggles.  These will be made to fit with a standard bike helmet and will have sticky plastic on the straps so that they will stay in place on your helmet.  I rode with a pair last winter and was very happy with them.  Kept my eyes warm and didn't fog even under heavy riding.  Many also come standard with clear lens so visibility won't be an issue.

Link - Note these arn't the pair I have - just did a quick search and posted the first pair I found.  I am not endorsing these goggles or the company selling them.


How to cover a bicycle left outside for extended periods I'm about to start a new job, within cycling distance of home. Trouble is that the office is small and has nowhere to store my bike. So I'm going to have to chain it up outside each day.

I went to my local bike shop today to get a cover and was surprised to find they didn't sell them. The staff said most are no good: they are too thin and light to offer proper protection.

Is this right? If so, is there anything else I can do to protect the bike from the elements (I live in the UK so this is mostly rain rather than extreme cold)?

Don’t worry about it. A bit of rain or dirt won’t harm your bike.

Regularly lube and clean your chain (even if it’s not yet rusty) and everything will be fine.

Salt can be quite nasty but unless you ride close to the coast it won’t be an issue in the UK.

If you want to save yourself some trouble, make sure you grease the contact area of parts such as the seat post or pedal threads before installing them so that they don't rust in place and you are still able to remove them at some point in the future. The bearings of some parts (e.g. pedals, headsets) can be re-greased which could be a good idea to do every year or so.


What tools are required to begin building a frame? What tools are required to begin building a frame? Are there DIY substitutes for any of them?

Are there things that aren't requirements, but simplify the process enough to be worth the cost?

Aside from classes at a place like UBI, how do you start learning what is required to practice this art form?

Not so long ago every reasonably sized town in the UK had one or more bike shops that could build a custom frame. I cannot believe this has gone during my lifetime. Anyway, the entry into frame building used to be quite low. You needed a jig, an oxy-acetylene torch, lugs, a frameset and some brass alloyed specially for brazing.

There is a supplier of all of the above in the UK that you may wish to contact:

http://www.henryjames.com/ujig.html

Before investing in the whole kit you may want to have a go at brazing things together with the torch. This is great fun and with relatively simple projects such as repair jobs of non-bicycle things you can pick up experience with the torch.

Most frame-builders of yore bought tubesets with only those able to demonstrate skill being allowed to buy Reynolds 531. An even smaller elite were allowed onto 753 that you need to silver solder instead of the normal bronze brazing. You can start out with the 'gas pipe' hi-ten steel frameset, maybe to make something special such as your own recumbent. Then you can move on as you feel you want to to try the more expensive steel and fillet rather than lug construction.

I have no idea how you make the leap onto 6 and 7 series aluminium welding, but steel is a great material to work with and you will have a lot of fun keeping the lost art of frame building alive.

As for going on a course, what you really need is enthusiasm and someone to show you. You need to be an apprentice of some retired person that has skills in what used to be commonplace.

Entry into the above is really not that expensive when compared to a fancy road bike, you are getting me inspired to give it a go myself!


Why did both of my inner tubes blow out on a new bike I've only put 4 hours on? I bought a new Diamondback Trace hybrid bike about a month ago. Rode it twice for about an hour a piece and the last time for about two hours. I had no problems any of the times and inflated the tires to about 70psi each time, well within the range specified. A week after the last ride I loaded my bike into the back of my Honda CRV. I didn't check the pressures at that time but they were obviously not flat. I ended up leaving the bike in the Honda for 4 or 5 days before finally unloading it. It became immediately apparent that both tires were completely flat. I took a look at one of the inner tubes and there was a four inch split at the seam that runs the full side of the tube. it was about 90-95 degrees on the days it was in the car and considerably hotter inside the car I would assume. based on the fact that the tires were aired up when put in the car and completely flat when I pulled it out days later I kinda assume it had to do with the heat. I'm just curious if other people have had this happen to them or if it might be something else I haven't considered. id appreciate any insight you have to offer

I have had a couple of times that an inner tube blew up while the bike was parked in bright sunlight. It seems that high temperatures are a contributing factor, but overpressure? I never pump my tires close to the maximum pressure, mostly the pressure is in the lower half of the min-max range.

The pressure of compressed air increases proportionally to the absolute temperature, i.e. 273+T ;  T in degrees centigrade. Hence an increase from 95F (35°C) to, say, 140F (60°C) will result in an increase by only 8%. I don't believe this itself is causing the blow outs.

More likely the blow outs are due to an undersized inner tube in combination with a high temperature. Rubber is a material that behaves elastically in a limited range. Beyond a point it starts a plastic deformation. I guess that this point drops with higher temperatures. Most inner tubes are specified for a certain width range, e.g. 18<-->23C for road bike clinchers. The remedy is to buy an inner tube that matches closely with the tire width.


Fixed gear cranks loosening I'm new to fixed gear riding, and my bike only has a front brake. I have noticed that when I use resistance at the cranks to slow down, rather than the front brake, eventually the cranks will begin to loosen. I've tried thread-lock and torquing them down really tight, but they still eventually loosen up again.

(edit) It's a brand new bottom bracket and the cups are not slipping - it's the crank arm bolts that are coming loose. I will take a look at the crank arm interface to see if they are rounded off at all. It doesn't seem like it would be though, since once I re-tighten the bolts, the cranks are stable. It's only through the repeated "engine braking" that they get loose.

Is this just a thing that fixed gear riders deal with, is it a mechanical defect, or am I doing something wrong?

I guess your bottom bracket is a standard square taper?  And that your bike is getting a little old in years?  The fix is to replace the cranks.

The cause is that as you tighten the nut, the square taper hole on the crank mashes up close to the axle.  But as you pedal, and brake in your case, the cranks will minutely flex in the hole which creates a tiny space so fretting can occur.  This is when minor amounts of metal are rubbed off the inside of the crank's square hole - the bottom bracket axle is normally tougher than the crank metal.

Once there's a bit of play in the square hole of the crank it will never tighten up right again.  If you're handy with tools you might be able to take some metal out of the middle of each side of the square hole, but in reality its only a delay.

Worst case is your cranks crack through while emergency-braking.

Check out your local bike co-op.  Cranks are mostly okay on scrapped donor bikes, so they should have some in spares for cheap.


Road bike fitting: Fit calculator results look slightly different with the bike I am planning to purchase I am planning to purchase a Triban RC 120. My height is 181.3 cms and I am planning to get an L sized model.

Since I am new to road biking, after reading about it for a bit, I decided to get the bike fit done. I referred to this site to get the measurements: https://www.competitivecyclist.com/Store/catalog/fitCalculatorBike.jsp

The recommendations from the site and the actual measurements from the RC 120 are as mentioned below:

The top tube length looks okay to me. I am concerned about the Seat Tube Range params. Based on the measurements, I think my legs have a disproportionate length than the general standards.

I am confused as to whether I should go ahead and purchase this or not?

PS: I am planning to rent a Triban 500 for a couple of days to get the actual experience of a road bike before purchasing one.

The frame you are planning to purchase has a sloping top tube. This means that the seat tube is shorter than what it would be if the top tube was horizontal, and you simply use longer seat post to compensate.

On the other hand, the results from Competitive Cyclist calculator does not have any numbers for stack, or height measured from bottom bracket to top of headset. With horizontal top tube this is not a issue, because it is directly related to seat tube length, but with sloping top tube you have to calculate it from bottom bracket drop and head tube length. Since the fit calculator recommends an unusually tall frame, the head tube is probably fine, and if the handlebars are too low for you, it is easier to raise than to lower them.


Change bike fit to reduce amount I "lift up" on my pedals It's folklore than a benefit of clipless pedals is that you can generate power while pulling your foot "up" as well as pushing it "down". I've noticed that under very particular circumstances (while on an indoor trainer, in non-ERG mode, on a climb) that I've started having slight pain which is easiest explained by this point.
Note that this pain has only shown up in these circumstances (which I can easily avoid) and I've always stopped immediately when I noticed it (and it did not linger after that). This is to say that this is a rather minor medical issue, so I'm unlikely to schedule an appointment over it during the pandemic. This means that my options are either:

Try to fix it myself (likely via adjusting bike fit)
Only ride outside/in ERG mode during the pandemic

Either one of these seems fine, I just thought I'd ask for advice about the first before jumping to the second.
In particular, I've been having some pain (roughly) in this region of my left foot:

People other places online say that this part of your foot is responsible for lifting up your toes. I suspect that poor bike fit (and poor pedaling form) is causing me to try to do precisely this. Are there modifications that I could make to my bike to make this movement less likely/"encouraged"?

I would suggest that changing your bike fit to optimise the mechanics of riding a turbo trainer is somewhat cart-before-horse.
However to take it seriously for a moment, if you want the best possible bike fit for pulling up on the pedals on your trainer when the resistance goes up, this will probably involve substantially changing the current relationship between hip/shin/ankle etc. E.g. putting the upstroke of your pedal cycle where the downstroke currently is might do the trick. This may have... consequences for other, perhaps slightly higher priority, aspects of cycling.
I would not describe your issue as originating from poor bike fit or poor pedalling form. I would say it originates from doing something that you would never normally do in the course of riding a bike, and so that the solution is to... not do it (i.e., your option 2)


shifting (hah!) from downtube to integrated shifters My old racing bike has 1991-era Ultegra, but I have gradually accumulated a nearly complete set of Dura Ace 7402 (mostly new in box) and plan to upgrade the bike. 7402 was a transitional release and offered both downtube and integrated shifters; I have both. The bike is currently outfitted with downtube shifters. It is feasible to install integrated shifters on such a bike? What happens to holes and bosses for the old downtube shifters?

Generally, have people regretted making such changes to an old bike? Does anybody suggest I just stick with downtube levers?

You just remove the downtube shifters, put cable stops in their place on the bosses (e.g. Shimano SM-CS50), and then route the cables for the brifters using those cable stops like you would any other bike. Tons of people have done this and are perfectly happy with it.

There isn't a problem with doing this so long as the shifters are matched to  drivetrain  (i.e. the cable pulls are matched, and everything is for the right number of speeds in the front/rear).

As for whether to do this or not, completely dependent on how you feel about it. Note that you can likely make a pretty penny selling the Dura Ace 7402 stuff and running a newer Shimano Claris/Sora or Microshift shifter instead (which is likely better than the old Dura Ace shifter anyway in practice due to fresher grease, ergonomics and trickle down engineering over the past 20+ years).

Note that Dura Ace pre-1997 used different cable pulls than the rest of the Shimano line, so you can't just bolt the Dura Ace shifters to the existing drivetrain.


Bottom bracket Stronglight JP400 equivalents I need to replace my bottom bracket cartridge because it is knackered. After a bit of reading it seems that there may be many types of cartridge variations (axle lengths, threads, size of square taper, etc etc). So I'm not sure how to fully specify the required replacement so I can be certain it will fit (other than buying the exact same part).

The old part is marked as a Stronglight JP400 122mm.
Chainset is Shimano.
Bottom bracket shell width is about 69mm (as near as I can measure it). Frame is aluminium.

From what you say, you need a bottom bracket with:

length = 122mm (as you state)
width = 68mm (you say 69mm, but 68mm is a standard size, could you be 1mm out?)
JIS standard taper (this will make sense to you when you start looking at BBs, the other standard is ISO. In JIS, "J" equals Japan, I suspect in JP400, "JP" also equals Japan)

There's one last variable, unfortunately. This is how the bottom bracket attaches to the frame. It screws in, but there are two different types of thread in common use, English and Italian. The type of threading used depends on the manufacturer of your bike. As a generalisation, Italian threads are (surprisingly) used mostly by Italian makers, the rest of the world pretty much uses English.

So, most likely you'll want an English thread, but you should check this (do you know the manufacturer of the frame?) before buying as the two threads are most definitely not compatible.

NB as always there's a page on Sheldon Brown's website with good information on BBs.


How do I prevent my hydraulic brakes from getting pressed/damaged when the wheels are off? When I was buying my bike, the technician in the shop told me not to press the brakes when the wheels are off (detached), otherwise the brakes will get damaged (I don't know how).

I need to detach the wheels for a few days and I want to clean the bicycle in the meantime. I will be moving it a lot, rotating it upside down, etc. How do I make sure the brakes don't get damaged during this process?

Since bikes are usually shipped to the dealer with the wheels disassembled from the frame, the disc calipers often each have a plastic separator pressed into them that serve to prevent lock-up during shipping. The Hayes company even puts their brand logo on theirs. Since these are removed during assembly, you might be able to ask a repair person at your local shop if they have any extras lying around that you can just have to keep.

EDIT: Here's a link to a how-to that gives the same advice, plus has some photos of the separator in use... http://www.singletracks.com/blog/mtb-repair/hydraulic-disc-brake-service/


What can women do to get comfortable in the saddle? I am fairly new to cycling and have a road bike which I am really enjoying but I cannot get comfortable in the saddle. Not so much bum bones, but lady bits! Any suggestions?

Saddles can be very specific to the individual...but some general advice:

Try to find a local bike shop that will let you test ride different
saddles. Five minutes on a trainer is not enough, a good bike shop
will let you take a saddle on a real ride.
Talk with others that have similar biking style. A great mountain
bike saddle does not always make a great road saddle. A bit of an angle change or moving the saddle a bit forward or backward can have a big effect.
Try some saddles that are "lady specific" and those that others say
work well for the lady bits. I've heard good things about the Selle
Italia Lady Diva and the saddles from Adamo (the Adamo's are not 'lady specific' but the cutout seems to have similar effect).

Also, you may want to invest in some decent bike shorts and a good anti-chafe creme (I like 'Blue Steel Sports').

Some of the "issues with the tissues" will fade as you spend more time on the bike, but some won't unless you get a saddle that works for you. Don't settle...try different saddles until you find something that works for you.


How well are new helmets packaged? I am considering buying a new helmet online, which means it'll be delivered to my door by courier.  In my experience, couriers can be careless with parcels.  Should I be concerned about this, or are helmets packaged so that they're safe even if knocked about a bit?

In case it matters, the brand of helmet I shall be buying is Specialized.

Helmets are like hats and shoes — everyone has a different shape head or foot and so the standard sizes really don’t apply. Some heads are pointy, some are flat. Different helmet companies use different head forms — and some even use different shapes between their different helmet line. So a ‘L’ for one helmet might not be the same as an ‘L’ in another.

So I’d recommend going to your local bike shop and get a properly fitting helmet. You’ll be surprised just how much better it fits on your head and how much more secure it is.


Wobbly stem: serious issue or not? I went test riding a second hand bike. During the test I have found that the stem was wobbly around the axis defined by the red star in the picture.

I have tried changing the tilt of the stem to check if it depended on the position, to no good. The stem kept oscillating up and down around that axis.

Is it a serious issue (so a no go for the bike) or is something that can be easily fixed?

That's an adjustable height stem. Looks like it has some sort of quick release and adjustment.

If it is irreparably loose it's a safety issue. The joint could collapse and the handlebar would drop down and forward suddenly.

Either: pass on this bike, or negotiate a lower price with the seller and plan to replace the stem. You'll need a riser stem for a threaded steerer tube. These are not too costly and easy to install with common tools, usually just a couple of sizes of hex wrench.

BTW, the brake lever angle looks wrong, seems to be angled down too far. Levers should be in line with your arms when sitting on the bike.


Is a tyre with sideways bulge going to cause damage to the rim or the hub or the axle? My Schwalbe Marathon plus tour 26'' x 2.0 has a sideways bulge (both rear and front). In between the 2 tyres and tube there is a  anti puncture strip.

The rim seems not to be the problem.

I think the strip is the cause of the tyre's sideways movement. The tyre is already tight/difficult to mount. With the strip mounting  is even harder.

Will such a bulge / sideways movement eventually (i.e. in the long term) cause damage (e.g. by bending)  the rim, hub,  axel, or bearings ?

I am interested in the consequences of this sideways movement not how to fix it.

Update

The bulge is not pronounced. It is at a single spot. I see it when looking down on the tyre (bicycle is flipped over and resting on saddle). When spinning the wheel the tyre suddenly moves right then left (wobble). This happens over 10degrees arc.

I cannot determine the tyre pressure. I've pumped the tyre hard - my guess 3bar. I used soapy water between the rim and tyre.

I can't say 100%, and full caution etc that if it's bulging that has to do with casing failure/damage or installation error then you should stop riding it, but it sounds like it's probably distortion caused by imperfections at the casing seam. Marathons, for everything nice about them, are a little notorious for this. Schwalbe will generally warranty particularly bad ones, which if you can feel it clearly while riding I would say these are. At times I've seen a lot of them that needed to be sent back for reasons much like you describe, suggesting a QC step getting missed or a machine not working right or the like. As the incidence of the problem has seemed high during certain time periods, it doesn't strike me as unusual to have two tires with it, and in fact that both tires have the issue suggests it's the seam rather than casing damage.

You can usually confirm that it's happening at the seam by examining the tire to see the look of the fabric layer under the rubber, or inside if you have the tire off, then following around to where you see that pattern disrupted, stacked double for a small bit, etc.

I've speculated that the kind of left-to-right diagonal distortion you describe is caused by something along the lines of the cuts of material not being square or the seams not putting them in a square orientation.

Riding the tires like this won't typically hurt anything except perhaps your enjoyment and steering control. It won't affect the tube, rim, hub, etc. Also, the distortion by itself from messy seams usually doesn't imply any inability of the casing to constrain the tube. If you're using rim brakes then you'd want to make sure the distortion isn't causing rub between the tire and pads or brake arms. And you also want to make sure the bulge isn't causing that spot to get close enough to the frame/fork to cause rubbing or clearance too tight to allow for some debris build up.


What kind of maintenance does a shimano dynamo hub need? I have a shimano dynamo hub on the front of my bike.

Does it need any special maintenance, or maybe it needs just a little synthetic grease once a year, like a normal front hub?

The common Shimano Dynamo hubs don't actually use sealed cartridge bearings, see the DH-3N71 and DH-3D72 techdocs. Shimano dynohubs do use good seals, however, and should hopefully be maintenance-free for many thousands of miles.

Alistair Spence has a good exploded view of an Alfine DH-S500, which is very similar to the DH-3D71.  He also links there to a disassembly guide PDF, the original of which can be seen (minus images) in the internet archive.  The steps are basically the same as a standard front hub, with the caveat that it is important to be careful to avoid breaking the axle wire.


Suggestions for removal of old chrome? I'm redoing an old BMX-style handlebar, but its been treated badly and there is rust under a lot of the chrome.   Its not saveable, so what is the best way to remove the chrome so I can treat the rust?

Ideally I'd get it shotblasted, but what else can I try first ?  I have tried:

Manually scraping with a knife - the bars are round and curved so a flat blade only clears a very narrow line.
Spinning wire wheel/wire cup on a drill - works but slow and tedious, and makes a mess of little slivers of chrome.

Is there a liquid soak I could use to get under the chrome?

In the end I had success using a grinding wheel and a 100mm / 4" grinder to remove all the slightly loose chrome.  The good chrome under the grips simply wouldn't move, so ended up being ground off by the grinder wheel.

This left a terrible surface, with many small flattened patches and diagonal scoring.  It was no longer round.  I spent a half-hour with 80 grit sandpaper, then 160 grit then 400 grit paper.

It was a slow process, and ultimately finished, it was no fun at all.

Then I immediately primed the bare steel to prevent any further rust from developing on the virgin steel surface.  On top of that I will put several coats of black spraypaint, and then a couple of clear topcoats.

I didn't get a photo of it before painting, but here's one showing one coat of primer.  Looks like its been peeled with a vegetable peeler, then zoom in to see the scratches in the "around" direction.

Final edit - here's the finished bars on the scooter.  That's two coats of primer, two top coats, and one clear coat on top.

Check out the zoom on this one:

The Stem Cap is alloy and it had white aluminium oxide "rust" , so the same treatment has left a different look.   I left the four offset stem bolts chromed and unpainted, because in my experience painting nuts and bolts is a waste of time.


Chain catching after derailleur change I am trying to figure out why my chain is catching with each revolution.  You can see it in this short video
[

The chain is constantly catching the derailleur, every few links or so. It's not a stiff link in the chain - unless the chain is made of stiff links. The chain does not look like it riding onto the next largest sprocket either.
The derailleur is the new factor and it looks like the chain is catching in the cage. I'd check the jockey wheels are rotating freely. I'm guessing one jockey wheel is catching at some point in its rotation.


Alternative to tuning automatic hub? I am contemplating purchasing an automatic gear hub, namely the SRAM Automatix. One of the criticisms leveled at this hub is that it shifts up too soon. The default settings can however be adjusted if know what you are doing, as this article explains:

http://mccraw.co.uk/sram-automatix-review/

Would using a smaller chairing on the crank-set have the same effect???

(I would rather do this than mess with the delicate innards of the hub axle).

Unwinding the spring, as the article states, will make the hub to shift when you're going faster.

Without touching the internals, the hub will shift at the same speed, no matter how high the cadence is. By changing the chainring-cog ratio you adjust the cadence at which the shift-speed is obtained.

So the answer is no, there is slight difference. By doing what you propose you can make the whole set shift at higher cadence, but at the same angular velocity of rear wheel, so at the same speed.

If you want to shift at higher speed without modifying the hub, you need bigger wheel (if possible).


How to tell what length of chain to get? I am replacing the chain on my road bike soon.  How do I know how many links to get?  Does it have to exactly 114 or 116.  Or is it not a big deal?

I ordered a 116 link chain.  Will I need to shorten it?

Thank you.

If your old chain was 114 links (assuming it was the right size to begin with) then it's a good idea to take a couple of links out of it. It'll still work with two extra links but shifting may not be optimal and the chain will fall off more easily. Keep in mind that one chain link is composed of an inner and outer link, so a link is actually two pieces with a hinge in the center. This means that to remove two links, you'll actually remove four pieces of chain with three hinge points.

If the old chain was 116 links and you're trying to replace it with a 114 link chain, you'll run into problems. A chain that is too short can jam when shifting and puts puts too much strain on your rear derailleur.

To determine the correct length, wrap your chain around largest chain ring in the front and the largest rear sprocket, without running it through the derailleurs. Make sure that the chain is long enough for one full link (again, inner and outer) to overlap and you'll probably be spot on.

You can read more about it here: http://sheldonbrown.com/derailer-adjustment.html#chain


Please help me identify this cassette I recently found this cassette that appears to have only 5 speeds. No locking or anything. Is it incomplete? Can it still be used with a normal freehub (with spacers of course)?

Thank you!

It's an incomplete 7-speed 11-34 Shimano CS-HG50, the model name is written on lockring. I think you can use it with spacers/lockring or source missing parts from another 7 speed cassette.


Why are bicycle tubing diameters often metric approximations of imperial measurements? This is related to my previous question about seatposts and handlebars, but I’d like to generalize the question this time.
The majority of bicycle tubes are metric equivalents of imperial sizes. The point about engineers choosing the best size for the application was brought up in the previous question, but the fact that this is so common leads me to believe that it can’t simply be a coincidence. What makes bicycle manufacturers lean towards these unusual decimal sizes of tubing? Is it availability? Tradition? If anything, standard metric sizes would probably be cheaper to purchase tooling for.
Examples: seatposts, seatpost clamps, steerer tubes, and handlebars (except the pointless MTB 35mm standard).

The decimal sizes such as 25.4 and 28.6mm are not "unusual" sizes. They are actually the standard sizes. You can count on engineers to do the easy and cheap thing, so they use the standard sizes. "Standard metric size" tubing (that would presumably be sizes in a round number of millimeters like 25mm or 30mm) is not really a thing in the world of chromoly tubing, and doesn't practically exist.
The reason the standard tubing sizes are not a "round" number of millimeters is, of course, historical.
Chromoly tubing is not just used for bicycles, and it wasn't invented just for bicycles.  According to Wikipedia, it was invented in 1885 and commercialized around 1891. Chromoly tubing was used extensively to build airplanes (and still is for some small airplanes) because it was strong and light enough to displace wood construction, which standard steel was not. The standard tubing sizes were based on inch measurements, because it was commercialized in a country and an era where inch-based measurements were the standard. And these sizes are still the standard sizes today...they were simply re-named to metric by calling 1-inch tubes 25.4mm, 1 1/8" tubes 28.6mm, etc.
If you shop at a chromoly tubing supplier such as Aircraft Spruce or Wick's Aircraft Supply you will find that chromemoly tubing is available in sizes from 1/4" up to 2+ inches, typically in increments in 1/8-inch. This is plenty of choice of sizes for any engineering need. At the small end of the scale, there are also 5/16 and 7/16" tubes available just in case a 1/8-inch jump is too much. These are the only size tubes available. There are no commonly available tubes in "round" metric millimeters.
When countries began the switch from inches to millimeters, it would be possible to start using 25.0mm tubes instead of 25.4-inch tubes. But then you would have to change all of the tube-making factory machines, all the building fixtures for building things, and all the pre-existing airplane and bicycle designs in the world, and even make new lugs for bikes. Even today, there is no justification for doing that just so that we can all have the small aesthetic benefit of looking at "prettier" round number of 25.0 instead of 25.4. Before widespread metrification, there was even less incentive to do it because 1-inch was actually the more standard way of measuring things anyway.


Why does my road bike come with only one valve adapter? My front tire has the skinny valve (I believe it is a Presta) and so does my rear tire. But my rear tire also has a screw-on piece that goes over the valve which I believe to be an adapter. Do they simply provide one adapter because it is cheaper and you can move it from one tire to the other?

Because you only fill one tire at a time.  The adapter screws off and can be used on either tire if needed.  It can also be easily stored with your patch kit, so it doesn't need to be on the bike.  I only keep one around in case I get stuck with only a schraeder pump at my disposal.


How to dress for biking 3 miles to work in 40°F (3°C) and below so not to sweat to much but still keep warm I bike to work. It's about 3 miles. I live in Minnesota. It is getting cold. When it is like 40 and below I bundle up but I sweat  and then I am hot so I lose a layer and then freeze. Should I wear like a windbreaker or that under armor stuff? I get to work and my body can not tell if its freezing or sweating.

It depends a lot on you. I live in Illinois and I'll go out in a T-shirt and shorts in the 40's for bike rides.

But if you want some additional warmth in the around 40F and 3 miles, I'd say maybe some thin gloves (I have a set of Underarmour coldgear running gloves which are useful for longer rides in the 30s) and a hoodie - you might be cold for the first 2-3 minutes but then you'll feel fine. If you find that a hoodie leaves you cold for the whole ride, maybe add a wind breaker with some ventilating holes.

In general, you shouldn't dress enough to feel warm when you're getting on the bike. You'll generate some extra heat, so in most cases, the right amount of clothing will make you feel a bit cold for the first few minutes.

A ski jacket is way too much bundling for riding in 40 degree weather (given that its probably overkill for even just standing outside).


How can I repair a swollen tire allowing visibility on the inner tube (picture provided)? I have a new problem on my bike which occured after patching my inner tube. Since I put the patch on, my tire is pushed out away from the rim near the intake valve (not near the patch). In the picture below, you can see the inner tube between the rim and the tire (partially hidden from view by snow). This is the case only on that spot, and only on that side. I can still ride the bike (I've been riding it like this for two days) but I can feel a small bump every time my wheel make a full rotation. Mostly, I'm afraid it will break soon.

The question: What's causing this problem and how can I solve it?

The picture does not make the situation totally clear, but it appears that tube is not centered in the tire, and the tire is not centered over the rim.  This tends to happen especially near the stem, because the thicker part of the tube gets caught between tire and rim and prevents the tire from sliding into place.

Deflate the tire, then press the valve stem in about 1/2 or 3/4 inch while you wiggle the tire to get it around and under tube.  Inflate slowly, and if you see the same thing again, repeat the process.  It may take two or three tries to get things lined up..

(If, on the other hand, what we're seeing is the sidewall failing and the tube pressing through the sidewall then the tire's toast.)


How to fix a clanking rear wheel/flywheel On my single speed--a POS Bikes Direct bike--the rear wheel makes a clunking noise every time I pedal. I think it is coming from the freewheel and it's basically a CLINK! CLONK! noise that is driving me nuts.

I should mention that the seat stay on the left side of the bike is slightly longer than on the right. Therefore the back is asymmetrical. The tire rides perfectly in the center of the rear dropouts and between the chain stays. However, the tire is a right aligned to the right seat stay.

Here is a visual I sent to Bikes Direct to try to get them to fix it:

And here are pictures of the bike from various angles.

From the comments above, it seems that it really is a free wheel that is making the noise.

Apparently cheap free wheels can be like that. Lubing them can help. This discussion has some extra info: http://forums.roadbikereview.com/fixed-single-speed/fix-shimano-freewheel-clunking-noises-150432.html

TL;DR version: Get some gear oil or grease gun and apply liberally.


Tubeless tire deflating through sidewall On my mountain bike I have Continental X-King tires (tubeless ready) on tubeless ready rims. I rode them a couple of times with tubes and now I went for tubeless setup with Stan's NoTubes Sealant.

At first everything looked fine, but they keep on deflating slowly. From 3 bar to 1 bar in roughly 10 hours. I've submerged the tires in water to see what's wrong. There are no major cuts or holes, just very small bubbles are leaking through the sidewalls. I did a couple of rides to distribute the sealant inside the tire, I also tried leaving the wheel laying horizontally overnight, but no luck so far.

Is it going to fix by itself after a few more pump-ups, or is the tire bad?

I've found Contis in general to be a bit harder to seal and take up to a few weeks of riding before they settle down.  I've tried Mountain King II and XKings both the "Protection" versions I also have friends who have tried this.

Two things that might help

Before fitting wipe the inside of the tyre with Isopropyl Alcohol.  The theory is it removes the "release compound" which the sealant might have issues with.
Put lots of sealant in (like 150-200ml) and ride for a couple of weeks.  You can then remove the excess sealant if they've settled down (either using a syringe through the valve or by pulling one side off the rim).  Riding generally seems to be much better than wheels sitting in the shed for sealing.

I've fitted 3 new Mountain King 2s and an XKing and the last two I fitted seemed to be better using the techniques above.  Obviously I've not done an "A/B" test so this is just my experience.  My current fix is to buy Maxxis instead which seem to go up no problem.


Do i need to lube up my chain I didnt ride my bicycle for almost 2 years now. It was in my room all this time. Do i need to lube the chain up or am i good to go? Thanks! Benjamin.


Buying a new bike for under $1500 - best option for hard terrain on a budget I am upgrading my bike which is exciting but I can't spend too much. Do I sacrifice carbon for aluminum if that gives me the option to go full suspension. Do I go for a solid carbon hardtail that may sacrifice some of the trail comfort for the durability. How much of an advantage is the full suspension over hardtail if you can only buy one for $1500?

At 1.5k it has to be a hardtail. Rear suspensions need to be done right to be worth having in the first place. If I was a long-travel guy (I'm not) I would start looking at FS bikes once my budget passed 2k.

As to the frame, 1.5k would get you a cheap/heavy carbon frame or a top quality aluminum frame. I'd go aluminum.

The above assumes that you are buying new...  I would consider buying used.

If I were you, I would get a used aluminum FS. I wouldn't mess with a used carbon bike, that can be risky.

Brand and model really doesn't matter if you know your components. If you have no clue how to identify good components, you should stick with big, well-known brands like Trek, Cannondale, Giant, Specialized, etc.

Good luck!


Could I have enough chain retention on a 1X system with just a narrow wide chainring without a clutch? My bike is a 2017 Fuel EX 5, i am considering converting it to a 1X (pronounced '1 by') chainring. But i am unsure if i will get enough chain retention to stop my chain falling off with just a narrow wide chainring. Has anybody else tried this?

Thanks

EDIT: I am referring to trail riding

It depends on the terrain you are riding. If you have lots of rocks on your trails, like in Mediterranean countries your chain will fall here and there. On the other hand, if your riding terrain similar to nice flowing Alps singletracks, having narrow-wide chainring will probably be enough.
Also consider installing a chain guide, it costs about 10$, weights little and can save your chain from falling quite a lot. And don't forget a beefy chainstay guard, otherwise the sound of chain hitting alloy can drive you mad :-)


Carbon foot print from the manufacture of bikes? It was said on National Public Radio in the US that in most cases the carbon foot print from the exhaust off your old car would be less in a life time then carbon footprint to manufacture new cleaner car for you. So unless you are going from V8 to a hybrid it is better just to repair it for the Earth.

That made me think how far do you have to travel on a bike to equal out the carbon foot print it takes to make a bicycle or an electric bike?

We can do some rough estimates.  Let's assume that bikes are made exclusively of metal, and that only the mass of the bike counts (no energy consumed in welding etc.). Looking up the carbon footprints of aluminium and steel we have:

Material    Tonnes CO2 per tonne material   Source
Steel (tube)    0.857                       http://www.newsteelconstruction.com/wp/the-carbon-footprint-of-steel/
Al (best)       3                           https://www.carbontrust.com/media/38366/ctc790-international-carbon-flows_-aluminium.pdf
Al (worst)     20

So a bike weighing 10 kg would lead to somewhere between 8.6 (steel) and 200 (aluminium, refined using coal power) kg of CO2 emitted.

I couldn't quickly find reliable figures for carbon fibre or rubber, but metals are very likely to dominate based on the share of the mass in a bike, and the market share of bike frames.

Compared to an efficient car with 100 g/km of CO2 emissions, you'd have to replace 860 to 2000 km of driving with cycling for the emissions of making the bike to offset the emissions of using the car. This is a small enough distance that we can neglect other consumables.  While not a direct comparison it's a helpful one -- many people have a car and are being encouraged to get a bike and use it.  Food makes things interesting. Strava claims I burn 26 Cal/km on a hilly ride.  If I got that from eating beef alone (as a worst case), that would be something like 10 g of beef per km, or apparently 270 g CO2e per km. Of course we all know carbs are much better for powering our rides; typical sources are 10× better than beef.

Returning briefly to the original claim, when I've seen this claimed it tends to use low mileage figures, and neglect the fact that the metals in cars tend to be recycled (for Al this makes a big difference).  It would make a good question at skeptics.se if you could source the claim more thoroughly.


Which rack top bag fits an 11" MacBook Air with space for a little padding? The goal is to carry a change of clothes and the MacBook Air (1.7 cm high, 29.95 cm wide, 19.2 cm deep and 1.06 kg) on a 14km commute. I've used Ortlieb panniers (on a Tubus rack) but I don't like the way my heels can hit them, they way they stick out on the sides or the way they add drag. Nicely made though! Also I don't want all the weight on one side and I don't want to carry two of them.

A backpack is way too sweaty.

The best rack top solution so far is a Rixen & Kaul Rackpack 1 mounted on a matching Rixen & Kaul Freerack (sorry, can't find a link for that one). A MacBook Air 11" (bare - no sleeve), a pair of jeans and a T-shirt are a tight fit. Other stuff goes in the side and it's workable. But I can see that it isn't a great solution because the laptop has to be placed in diagonally with the thin edge sticking up. Over time the sharp edge of the laptop is definitely going to wear through the bag, and any crash is going to cause a lot of damage to the laptop.

I have also tried a Deuter 10l rack top pack - it is also too small, not quite as good as the Rixen & Kaul and the velcro attachment is much slower and less secure.

I've got a lot of nice things to say about Rixen & Kaul. It is a very well made bag and when I had a problem with the clip they sorted it out right away. This bag is just a little bit too small to be perfect. The click fix system is great. I have thought of removing the click fix mount and assign it to some other bag but it's a last resort and chances are my home-made solution is not going to be as nice as the ideal bag I'm wanting.

Update: I looked at the Topeak Office MTX and it isn't for me. Inside it has a big divider/pocket thing that takes a lot of space and can't be removed. It doesn't appear to be particularly sturdy, especially the attachment mechanism. Their beam rack product has a quick release fastener rather than bolts so anyone could just unclip and walk away with it. The rack is just not finished as well as the Tubus/Rixen-Kaul racks I already have, it feels chunky and heavy.

The solution looks like it is the Ortlieb Office High Visibility QL3 - 30x40x17cm, 21l (unfortunately it's more expensive than the Topeak bag and rack system). While it is still side-mounted the QL3 system attaches to my existing rack so I can still use my current rack top bag with it's special mount when I don't need so much space. Position on the bike is widely adjustable so heel strike isn't an issue. It's rectangular so folded clothes will hopefully stay folded rather than falling down into the pointy bit of my older tapered Ortlieb panniers. It is waterproof without needing a rain cover. It's eerily reflective over its whole surface.

Topeak has a laptop bag called an MTX Office Bag that attaches to the MTX racks and lays flat.

It is said to accept a 17" laptop so yours should fit in great and given how thin they are, you should have room for a change of clothes.  You might be able to use a padded sleeve.

I tried to put my older 15.6" Dell 131L in my Topeak DXP pannier and it fit, but not much room for other things.  However, I recommend getting a padded sleeve, and with mine it would stick out an inch or two and really no room for anything else.

These bags are pretty good about keeping stuff dry on short commutes (30 min) unless it rains really heavy (and then it was the bottoms of the pannier due to tire spray), but a large locking freezer bag will do the trick nicely.


Coaster brakes vs. Handle brakes i will be honest.  I am nearly 50y/o and not in tip top shape either. I have not owned a bike since I was 12y/o. I want to buy a bike. I am looking at the cruiser bikes.  Most come with coaster brakes.  I am not sure what to buy. I am new to biking, so I don't know.  I have heard more positives about handle brakes but also heard a lot of things could go wrong, and what if I get stranded somewhere? What would I do? Please advise.  Sorry if I am rambling.

There's a small chance you don't have as much hand/arm strength as you used to.  A coaster brake provides a way to slow while leaving your arms free to focus on steering.

That said, a coaster brake is a rear brake only.  The best stopping happens with the front brake, so ideally you'd have both, a coaster for the rear and a hand brake lever for the front.


What size nipple should I use for granny bike rim? I am going to build my first wheel using the Ryde V38 rim (Westwood type).
The shop where I ordered the rim, says it has 5.5 mm spoke holes.

The nipples that come with the regular 2.34 mm (13 g) spokes are specified to have a 5.9 mm nipple head diameter.

It seems like that is a rather small overlap, so I am wondering if I should use "large head nipples" (7 mm) instead?

5.5mm spoke holes sounds ridiculously large and it would not surprise me if that's not correct. Ryde don't mention it on their generic V38 page nor do "Flying Pigeon" on their Westwood listing but they do suggest 2.0mm spokes. No mention of needing large head nipples though.

If you can try the large head in the rim before buying definitely do that. Otherwise I'd be tempted to wait and see, since if you need the large head nipples you'll need to buy them separately anyway so you only lose time by waiting to see if you need them.


Do merino wool base layers need to be skin tight? I have bought a Merino wool base layer for all the obvious reasons, they're raved about and have been sworn by by many a rider, and I was getting not only chilly in the winter weather but also wearing a cotton t-shirt and getting caught in the rain caused it to very quickly go cold, damp and heavy.

So I bought small and medium and settled for the small but even that is quite loose on me and a baggy fit. It certainly keeps me warm, no complaints there, but then I very quickly get too warm. They're supposed to be magic - keep you warm in winter and cool in the heat - but if it can't stop me from overheating when its cold outside, I struggle to believe it being any better in the summer.

My theory is that it needs to be a skin fit in order to achieve its wicking capabilities, and because it's loose, it isn't able to wick the heat direct from my skin, but rather heats up the air between my skin and the base layer causing a reserve of hot air which keeps getting hotter and thus causing my own mini personal sauna effect.

Am I right or totally wrong? I don't mind being wrong, but just want to understand the reasons I seem to be too hot and what I can do to resolve it.

I am also wearing a waterproof jacket over it which isn't very breathable. This could just as much be the problem, but I don't want to leave the jacket in case it rains as I don't know how Merino wool base layers - especially when baggy - cope when wet? (Another question maybe?)

Thanks.

I am also wearing a waterproof jacket over it which isn't very breathable

Well there's your problem.

The most wickable, breathable material in the world isn't going to achieve those properties if you put a plastic bag over it. If you don't want to be caught out in the rain, keep the raincoat in a backpack/messengerbag/pannier/whatever until it's needed.

Regarding how tight the base layer should be, I would say it should be pretty tight, especially when you first put it on because it will shrink up in the wash and loosen up considerably when you sweat in it. However, if it's a little baggy it's not the end of the world, it just wont wick moisture away as well.

Also keep in mind that everyone has different heat/cold tolerances. Two different people may require entirely different layers at the same temperature based on exertion, weight, preference, etc. If you're a hot blooded type, it might need to get a little colder before you put on a wool jersey. I know I'd catch on fire for anything above around 55°F


Axle - rear hub and washer thing a bit loose I have a rear wheel that has needed work 3 or more times in around 3 years (of not very regular riding) and I'm wondering if something is especially wrong with the setup on this FUJI road bike.

A few years back I reworked the axle on the bike - put some grease in it and set it. Later it had come very stiff. I opened it up and bought some cones to replace it - fairly chewed up.

This year I took it to a cycle-hobby shop as the wheel was wiggling like out-of-true, but no one portion of the wheel consistently rubbed. Sure enough, they say it needed bearings, now it trues up perfectly and all good?

Now, after a few rides and a few months, I'm seeing it is obviously loose and furthermore the little round washer was coming loose. Pushed it in and rode a bit, and this part is still not completely fitted in as I can push it in a little.

What is that part called, and is it safe to run with that a little loose? Is just tightening the cones and tightening/loosening likely to fix this for good or... for another year at least?

The chain goes forward just slightly when freewheeling but apparently that is supposed to be normal? Not sure if it is in any way related.

The round washer-like piece that's loose is a metal dust cover. It keeps debris and water out of the bearings. On some hubs they're pressed into the hub shell and on others they're pressed onto the cone, which is what this looks like. Having it be loose is consistent with replacing the cone with one that wasn't quite the right diameter to mate properly with the cover. There's not much leeway there.

The usual procedure for transferring the dust shield is to cradle it with a vise or socket and very gently tap the old cone through and the new one on.

You don't really want it to be loose because they're the hub's main line of defense against contaminants. If it's rotating around freely it may get damaged as well, and be unable to press into place on a new cone.

Replacing cones is a careful business of finding one where the ground part matches the profile of the original one well, making sure the ball track is falling in a good spot on it in practice, in this case ensuring it has the right major diameter for the dust cover, and then making sure the spacing of the hub is right when you're done. There are some in-depth treatments out there of this, Barnett's Manual has a good one, but it's a fairly big topic. Repeat problems with the hub coming loose, rapidly accumulating wear, etc are likely outcomes of the match not being great with the profile of the new cones. The balls may be making contact in an awkward spot of the curve or off of it completely. An extreme case of this may make the wheel not usable. It could be a good idea to look at the cones and see how they're wearing.

It's also possible that the cones were a good match but the cups are damaged and causing repeat loosening. If so that's likely to keep happening but take a long time to be an acute problem.

The chain behavior is probably some dryness or gumminess in the freewheel and not related.


Rear cassette 'ticking' forward, making chain catch, what is the problem and how do I solve it? I have a Giant Rapid 4, bought in 2009.

When freewheeling (i.e. rolling forward but not pedalling) on my bicycle, the chain catches. I had a look and I think this is because the rear cassette sometimes gets 'caught' slightly and moves with the wheel.

This doesn't seem to be a problem when pedalling, but when I am not pedalling and the front gears are not moving, the chain catches. It actually broke my chain.

Just put a new chain on, but I'm reluctant to ride it until this problem is resolved fully, otherwise the new chain will be stressed and may break again.

So, what could cause the rear cassette to be 'carried' forward by the wheel? Is it a bearings problem, or do I need a new cassette? Thanks.

Edit. I took off the cassette and dismantled the hub, it was the freehub body which was broken. It sounded and felt like one of the bearings inside it was broken. However the Shimano freehub disassembly tool is no longer sold and I couldn't find one second hand. The rim was worn anyway so I treated myself to new wheels and reused the old cassette, which was still ok.

Most likely the free hub is sticking.  The grease can get old and sticky.  Service the hub.  Lots of videos on youtube. Or take the hub to a shop.  And you can wear out a hub - some parts are serviceable.

Sticky hub is not likely to break a chain but it is a problem that needs to be corrected.


Reversing handlebar tape direction Based on the Park Tool guide on how to wrap drop handlebars, the bottom of the handlebars should have the tapes installed with an outward direction and reversing directions when it's on its way to the top.

The thing is, the guide is for drop handlebars with brakes/shifters in front. So I'm wondering, how does one reverse the tape direction if there are no brakes/shifters in front? Like say for a fixed gear where the brake is mounted on top of the bar?

You don't reverse the direction mid-way, as this would involve cutting the bar tape. You basically have two options:

Do as stated in your link and start with an outward direction. You'll end up the other way round as shown in your video, which means you'll have to cut the tape the "other way".
Start with an inward rotation in order to finish the same way as shown in the video.

Cool thing is, there are no limitations as there are no breaks. A few ideas:

Go-naked carbonite:

Simple and pure (with an outward rotation at the start):

Fancy (see this video for instructions):


Crown race for a fork with a straight 28.6mm steerer I have a fork with a 28.6mm steerer tube. It appears to be completely straight, with no flare at the bottom. I bought a bike with a damaged crown race. I bought a Jessica head set, but the crown race appears to expect a 30mm flare but my tube is 28.6 all the way. Can anyone suggest a solution?

Problems with the fork's crown race seat being under spec such that the race slides on and off without any interference are fairly common. Usually the gap is more on the order of 0-0.2mm or so. In almost all cases, this can be addressed by either knurling the seat with the Stein knurling tool, applying a retaining compound, or both. But I doubt either of these would work if the crown race area actually measures 28.6 as you say.

If it really is 28.6 all the way down, that implies a defective fork. It could potentially be addressed by getting a crown race seat from a framebuilding supplier and either brazing or bonding it on. The crown race seat being left off at the factory seems like the most likely explanation. Finishing it with either a crown race mill or an enormous, rigid lathe would be required.

You could also try a build up and knock down type approach with brass if it's a steel fork or a metal-reinforced putty otherwise. Loads in this area are considerable so there's some question whether it would work long term without breaking or crumbling.

A simple crown race that goes on and fixes everything doesn't exist, as 28.6 crown race seats aren't a standard.


General question about small transmission changes I am trying to wrap my head around the benefit I may get out of small changes regarding my transmission ratio.

Here is the premise:

11-42 cassette (Shimano M7000)
36-26 crankset (Shimano MT600)

I found that I generally don‘t use the lowest gears much - if at all - as the hills around here are more like bumps in the landscape.

That led me to wondering if maybe even small tweaks, like switching to a cassette with less teeth in the lowest gear as well a crank with more teeth would even be recognizable.

To summarize: Would changing above mentioned cassette and crank to

11-40 cassette and
38-28 crankset

even matter?

I am very interested in your experiences and thoughts about such small changes.

Supplementary question: would that change lead to compatibility issues?

Thanks!

I would say that changing the crankset by 2 teeth is not worth the money it costs. At least try to only change the chainrings first.

Cassettes are much cheaper so it is more natural to start there. However, your current derailleur has the minimum size of the largest cog 40, exactly as you proposed. It won't do much. So thinkink about also increasing the chainrings is natural.

You can calculate the difference using a gear calculator like http://gears.mtbcrosscountry.com If you keep the the smallest cog 11T, which you have to, only larger chainrings can enable you higher speed in flat sections and downhill parts where you control the speed by your power. The denser cassette can only help you to have smaller jumps between sprockets. But with 11-speeds you don't have too large jumps and off-road you don't need such finer ratios as road racer like.

So in the end the chainrings or, indeed, the whole crankset may be be a better investment.

This is your current setup http://gears.mtbcrosscountry.com/#29/2.10I1931I1370

With 28-38 you would get http://gears.mtbcrosscountry.com/#29/2.10I1542I1370

As you can see, your maximum speed at 80 rpm cadence would increase from 35.9 to 37.9 km/h. That means you could keep your cadence lower at higher speed if you want, not that it would be any easier to go high speed.

Changing the cassette to 11-40 does only a very marginal change and I would only do that when having to buy a new one.


How can I check if my bike is safe for touring? I have an old second-hand bike that I use daily for commute, and in a few weeks I want to take it on my first bike tour around Europe.

I'm a bit worried, since the bike is quite old (has some rust spots, a loose spoke or 2, etc.), that it might not be the safest thing to do. However it never had any problems while riding around the city, and unfortunately I don't really have money for a new bike or parts.

Are there some standard checks one can do to see if it's fit for touring? Are there any serious problems that I should be worried about?

Get the bike serviced, giving yourself enough time to thoroughly test it, so that if the service introduces any problems, you discover them long before your trip.

There is no standard test for worthiness, you'll have to rely on your judgement.


Aftermarket SPD-SL cleats Given that original Shimano SPD-SL cleats are not the cheapest, and do wear down quite quickly, looking for cheaper alternatives.  Have seen various aftermarket options for half the price.  Has anyone any experience in using these?

In the automotive industry, "aftermarket" refers to, from Wikipedia, all the secondary market for all vehicle parts and accessories, after the original sale, including replacement parts and accessories, whether made by the OEM or not. I don't frequently hear this term used in the bicycle industry, but it does apply.
Licensed copies
In this particular case, it's worth discussing patents. To my current knowledge, Shimano's SPD-SL pedals are still under patent. I see on Google that Exustar offers an aftermarket version of the SPD-SL cleat, although it has 4.5 degrees of float (vs 6 degrees for Shimano's yellow cleats, likely not a limiting factor for most riders). I believe this is a licensed version of the SPD-SL cleat. I have no personal experience with it, and I'm not sure how these licensed versions have been sold.
Exustar have made either licensed or slightly variant versions of Look cleats for some time. Cyclingtips' review of road pedal systems in general argued that Exustar's Look cleats were better in some ways than the stock ones in some ways. Clearly, Exustar know how to make a decent cleat in general. I suppose you could also look through the Amazon reviews for their SPD-SL equivalent cleat. In general, licensed copies should be OK. I would expect them to be equal to or worse than the original product or OEM version.
In cycling, I can't really think of a licensed copy of a product that's superior to the original. In some cases, rim brake pads come close: Kool Stops are noticeably superior to many stock Shimano pads, especially the low end ones. At the high end, I've heard it argued that the Swiss Stop BXP is superior to the stock Ultegra or Dura Ace pads. These pads use the dimensions of Shimano's brake pad holders, but I would not say these are really licensed copies (the pad compounds are different).
Xpedo and Exustar may make licensed versions of the Look Keo pedals and cleats, and these products may vary slightly from Look's design. It seems like they may not officially call their systems inter-compatible with the original Look Keo pedals or cleats. The Favero Assioma power meter pedal is built on Xpedo pedal bodies and cleats, and a different article describes those cleats as a Look variant. The same is true of the Powertap power pedals. Some users report that original Look Keo cleats fit the power pedals, but the fit may degrade over time. Garmin's Vector power pedals (the second link) appear to come with Look Keo cleats, and if so, then I would assume Garmin licensed the Keo design from Look. I'm not clear on the licensing status for Xpedo and Exustar, but given the designs appear very close, I would assume those firms had to pay licensing fees. John Weirath, a bike fitter, documented on his Youtube channel that the variant/licensed Look cleats may have some dimensional differences versus the original items. In that video, the difference was enough to require a different cleat position.
Un-Licensed copies, i.e. counterfeits
Dishearteningly, there may also be counterfeit SPD-SL cleats in circulation. One post on the Paceline forum, this blog post, and at least one person in this thread on the Bikeradar forum reported bad experiences with cleats that were suspected counterfeits (i.e. advertisement implied that they were Shimano cleats or didn't clarify that they were not made by Shimano). Complaints related to durability and materials quality. However, at least one person on the Bikeradar thread did report satisfactory experience.
In general, if you are buying components that you know to be knock-offs, especially illegal knockoffs, of a genuine product, I would assume that the materials may be poorer quality. This could mean that the plastic is less durable and may break or wear faster, or that the rubber bumpers may not adhere as well as the stock cleats. Also, the tolerances could be poorer, i.e. you may get a set of cleats that fit too loosely or too tightly in the pedals (i.e. the variance in the physical dimensions is higher than the stock cleats). Naturally, it's not a given that non-OEM parts in general will have substantively poorer quality and function than OEM parts. It's just that it's more likely with parts that are counterfeit.
Also, apparently you now need to be aware that Amazon and eBay may have counterfeit SPD-SL cleats, as well as other counterfeit items. I hadn't really known about people selling counterfeit SPD-SL cleats until the Paceline post. I think that knockoff may be a synonym. This refers to something that's just a direct copy, with no regard for legality.
I recall that eBay had a problem with fake Oakley sunglasses years ago, when I was more credulous (and yes, I got scammed). I ordered a set of CPAP filters on Amazon. They weren't OEM, and it was clear that they fit a bit looser than OEM filters. My opinion is that with a relatively low-cost item like a replacement cleat, I am not likely to bother with third party options unless I know the third party produces good quality. This would actually include Exustar's cleats, so I may try them next. Items not licensed by the manufacturer are out for me.
Terminology - more on knockoff vs. counterfeit
Above, I refer to suspected counterfeit Shimano cleats because I believe that many sellers are passing off their products as Shimano, and I don't believe they have the legal right to do so. It's generally possible to produce a knockoff product without violating the law. If Shimano's SPD-SL system is still under patent, I assume the patent covers the physical dimensions of the cleats, so it's probably impossible to legally make knockoffs that actually work.
Shimano did, however, let the patent on their SPD mountain bike pedals and cleats expire in early 2019. SRM produced a pair of power meter pedals, reviewed by DC Rainmaker, that are compatible with SPD cleats. I don't think people would instinctively call this a knock-off product - this is a completely new pedal design, and Shimano don't even offer a power meter pedal. In any case, Xpedo either produced SPD-compatible MTB pedals under license, or else they just started producing them in 2019.
Legal knockoff products do occur in cycling. One example of legally copying a product is the Rock Brothers version of the Spurcycle bell. Spurcycle failed to patent their bell, so Rock Brothers was able to legally copy the design - although, as I mentioned above, their version had noticeably worse performance due to poorer materials and construction. Spurcycle is a small company, and they simply did not know about the importance of patenting. I'd assume Shimano didn't forget to patent the SPD-SL system, or to renew the patent if they were able.
Alternatively, in 2018, DC Rainmaker reviewed the Magene Gravat 2 smart trainer. He has extensively reviewed smart trainers, and the Gravat appeared to directly copy the physical dimensions of Wahoo's Kickr. He described it as "a bit of a copy-cat trainer." In this case, though, there is also the internal engineering of the trainer (which has a flywheel, a drive belt, and various other mechanisms), and there's also engineering the software to drive the trainer. The trainer as a system may not be close enough to Wahoo's for them to raise legal objections, or it may be impossible to fully patent every aspect of the trainer (IANAL). Also, Magene's color scheme is clearly different from Wahoo's, so there at least should not be any confusing Magene's product as a Wahoo.
Less closely, Silca recently released a compact saddle bag called the Mattone. Some commenters on the Bikerumor article I linked accused Silca of ripping off the Velocolour Rocket Pocket. IANAL, and I don't even know if Velocolour applied for a patent here, but the Silca product may be different enough to not be considered a copy - for instance, the attachment mechanisms are totally different. In the fashion industry, brands rip each other off frequently. For interested parties, here is a Vox article discussing the existence of the phenomenon, and the public policy case both for and against stronger copyright laws.


Can I get an ebike with a 500 watt motor in Australia? I'm a bit on the heavy side, so I'd like to purchase an ebike with something a little gutsier than the usual 250 watt motor so that I can go up hills. Can these be purchased in Australia at all?

A 500W motor is not currently legal for use in Australia.

"In Australia the e-bike is defined by the Australian Vehicle Standards as a bicycle that has an auxiliary motor with a maximum power output not exceeding 200 W without consideration for speed limits or pedal sensors.[1] Each state is responsible for deciding how to treat such a vehicle and currently all states agree that such a vehicle does not require licensing or registration. Various groups are lobbying for an increase in this low limit to encourage more widespread use of e-bikes to assist in mobility, health benefits and to reduce congestion, pollution and road danger. Some states have their own rules such as no riding under electric power on bike paths and through built up areas so riders should view the state laws regarding their use. There is no licence and no registration required for e-bike usage.

Since 30 May 2012, Australia has an additional new e-bike category using the European Union model of a pedelec as per the CE EN15194 standard. This means the e-bike can have a motor of 250W of continuous rated power which can only be activated by pedalling (if above 6 km/h) and must cut out over 25 km/h – if so it is classed as a normal bicycle. The state of Victoria is the first to amend their local road rules, see below."

Quoted text from https://en.wikipedia.org/wiki/Electric_bicycle_laws#Australia


What is the ideal travel for dual crown fork? I'm planning to have my fork upgraded. Currently I am using Suntour XCM with 100mm travel. I'm reading a lot of MTB forums and a lot of them are telling that you may break the head tube if you use dual crown fork with high travel(160-200mm). Based on their inputs, the ideal travel for a dual crown fork is around 130-140mm. My bike frame is a hard tail enduro. Any inputs will be appreciated.

Given the frame is designed for 100mm fork, its unlikely its strong enough to handle riding that needs a 160+mm travel fork, and frame failure is possible. Its not the dual crown that is the problem - its riding a frame designed for 100 travel (typically XC) in a way that needs 200mm travel (typically extreme down hill).

Changing the fork travel changes the frame geometry and compromises handling. The original fork has 100mm, the bike is not designed for higher travel forks, anything more that about 120mm would starting to affect the handling. Above about 140mm, the bikes geometry would be all out of kilter, and it would be a completely different feel to what it is now.

For the same price, modern single crown forks in the 120-140mm travel are as good as any dual crown for enduro riding.  The original fork being a XCM100 also means its an entry level frame. I doubt the frame would benefit significantly from a decent dual crown fork over a decent single crown which would be nearly as stiff and lighter weight.

Adding all this together, if you really need more than 120mm travel, you would be better to buy a bike built for it. If you only need 120mm travel, a single crown fork will do the job best.


Which parts of a bike have reversed (left-handed) threads? Which parts of a bike have reversed (left-handed) threads?

There's 1) the non-drive-side left pedal-to-crank threading and 2) the drive-side right bottom bracket cup (apparently sometimes called the fixed cup).

Is there anything else?

Fixed gear hubs have left-handed threaded lock rings, so that they can't be loosened when the cog that is on right handed thread is turned counterclockwise.


My pedals are forced forward when the back-pedal brake is on I have to backpedal in order to brake. But when I do this, it works for about 3 seconds and then there's some kind of noise and my pedals start going on their own. The momentum of my back tire would push my pedals to keep going and I couldn't stop them with my feet.

I let my friend try riding it so he could see what it was doing and when he tried to backpedal, the seat came off.

What I'm guessing is happening is that your reaction arm (the thing on the left of the diagram) is not fixed in place.

When you brake the shoes of the brake are pushed out from the axle into the shell of the wheel hub. The idea being that the axle is fixed in place and the shoes drag against the shell.

If the reaction arm was undone, the friction of the brake shoes against the hub shell would be greater than the friction of the axle in the dropouts and so the whole unit of hub, axle and cog (fixed to axle) would turn under the rotational momentum of the wheel.

My guess is the 3 seconds followed by a noise is the time it takes for the reaction arm of your hub to overcome the friction and force its way past the chain stay.


How can I dress up a bike as a unicorn? Or a horse, of course.  The bike has to be rideable, and needs to return to normal afterwards.

Most years my city has what they call a "carnivelo", a family ride in which bikes, riders, trailers, passengers etc are encouraged to be in fancy dress and ride a car-free route.  There are photos online and videos of previous years on YouTube. Some years have more fancy dress than others.

This year the theme is "enchanted forest" so I thought a unicorn with 2 riders (my daughter fits better on her bike seat than in the trailer) would be suitable. We would of course be in fancy dresss ourselves. A "horse" could also pull a carriage based on the frame of the trailer with a new cover.

While the event itself is traffic-free, we'd have to get there somehow, which would presumably involve riding in traffic.

A minimalist yet inventive design by Korean designer Eungi Kim  has caught my eye:

You could use white PVC plumbing pipes and heat bend them.
Accompany it with similarly minimalist fancy dress and you're good to go.


Cyclometer interference from car detection loops? I've noticed several times lately when stopping at an intersection with a car detection loop that my wireless cyclometer (an Atom 4.0) exhibits some strange behavior. It continues to think I'm moving (as indicated by a triangle icon), the distance increases (by a tenth of a mile every few seconds), the average speed goes up rapidly (in accordance with the distance increase), but the current speed appears stuck at whatever the last real reading was, and the maximum speed is unaffected.

I suspect it's to do with the car detection loops in the pavement, since the only other electronic things on my bike are lights, and I've seen this with them off. Is this how interference might present itself in the cyclometer? Are the loops indeed a probable source? Can I try to shield something to avoid it?

The car induction loop seems to be the most likely culprit. Their operation rely on an induction coil being buried under the street in front of the lights [1]. When it detects a car, or for that matter your metal bike, as a result its magnetic field is increased. This magnetic field is used for operation of the lights, but its conceivable that the field will affect the operation of your wireless comp. It's questionable if it would affect a wired computer, as it would be shielded with the connecting cable.

When passing through the door in my local bike shop with my bike while having my cyclocomputer fitted I also see the same affect. This time its down to the anti-theft magnetic detection loops fitted at the door. [2]

I suppose the solution is to fit a wired comp instead. Or else make sure you stay well back from/in front of the lights.

[1] http://auto.howstuffworks.com/car-driving-safety/safety-regulatory-devices/question234.htm

[2] http://en.wikipedia.org/wiki/Electronic_article_surveillance#Magnetic_systems


Derailleur hanger moves when tightening quick release I have an old Trek T-900 tandem that my wife and I ride quite a bit.  It's got an 8-speed rear setup.

It's a standard (tandem) 145mm rear-spacing with matching hub, but tightening down the quick-release moves the derailleur hanger, screwing up the shifting.  I can re-adjust, but next time I remove the wheel, it shifts poorly until adjusted again.

This is an aluminum frame, so re-spacing it isn't an option.  Ideas of what is going on here?

Edited from my comments above:

The first thing I would check is whether the hanger is removable.

If it is removable, I would check that it is still bolted securely in place. It's pretty common that removable hangers sort of overlap with the dropout. So it's possible that the hanger is loose, and the QR is then clamping it firmly in to place, but then each time you remove and reattach the wheel it clamps in a slightly different position.  That could explain the tricky shifting.


Back wheel moving to left side Can't seem to find something similar so I am going to ask a question.

I recently bought a vintage(mid or late 80s) steel road bike and the back wheel seems to be moving off center and towards the left side of the rear triangle bottom part. The wheel is a tiny bit untrue but nothing out of the ordinary so I don't think that this is the issue. If I take the wheel off and put it back on again correctly it just moves a little bit to the left side after 10-20km. Any ideas on why this might be happening? First time I noticed it was because the tyre started rubbing on the frame and I don't want this to happen anymore.

Cheers,
Ivan

Thanks a lot for the comments, they did help a little at the time but did not solve the issue fully.
At the end I found there were a few issues with the rear of that bike.
The freewheel was wobbling a bit and had to be changed. The bearings of the hub had to be changed and the axle was bent so that was changed, too. Finally, the dropout was a bit bent, too on one side. After changing/correcting all of these the issue did disappear. But it was costlier than I had hoped  Unfortunately I cannot be sure which of these was the main issue.


Protecting jeans from saddle rub? I am looking at ways to deal with jeans aging prematurely due to saddle rub. While I could change clothing (not nessarily an option), as suggested in an older thread, I am wondering if there is such a thing as shorts to put over jeans than can quickly be removed. If not, has anyone experimented to see if this would help diminish the issue?

You could switch to a saddle that isn't as abrasive. That's one of the reasons people like leather saddles such as Brookes -- even if they're more expensive and heavier than plastic wonders.  The leather saddles also breathe and wick moisture and I've found that wet cloth abrades much faster than dry cloth.

There are also neoprene saddle covers which might reduce friction by allowing more slippage, but I've always found the squishy movement they cause to be more uncomfortable than comfortable.

ps. Many cyclists consider saddle worn clothing to be a mark of pride.


What is the purpose of spindle with longer non-drive side? I've just discovered that Shimano has 107mm and 110mm spindles in their BB (square taper) -- the first one is symmetric and the second one is asymmetric. I have read why BB spindles are right-asymmetric (longer) -- chainring clearance -- but Shimano released such BB that spindle is longer on the left side (i.e. non-drive).
I don't get it -- all the trouble with clearance is on the drive side, so once you have given length, you make it double. Where is the need for longer left-side of the spindle?

It may have to do with the mating crank arms. Sometimes one side had more of an offset than the other side.


Fitter suggested too short a stem I had my bike professionally fitted a few months back and the guy made some changes to it. One of them was going from a 100mm stem to a 60mm stem. The change felt better for my back, but the bike feels really hard to control and I can barely ride it while standing. I tried going back to the 100mm and just pushing the saddle forwards to compensate and have been feeling the position to be about as comfortable, but the bike handles well again. The question is: is pushing the saddle forward by more than suggested to me by the fitter (almost all the way) a bad idea? will this have a negative impact?

Assuming the fitter correctly positioned the saddle set back for you, moving the saddle forward could result in more knee stress and the potential for repetitive stress injury.  Keep an eye for early signs.  Your knees, hips and IT bands could all show signs.

Typically, the recommended order of operation in the fit is to first set the saddle height and setback, then set the handlebar reach. Saddle position is considered one of the most important positions for overall performance.

I find it interesting that the more shorter reach setup relieved back pain. Usually a stretched out position affects the shoulders and neck. You should also look into if you have back and hip flexibility issues.  Fit can accommodate flexibility issues, but shouldn't be a substitute for addressing the underlying issues as they likely affect other aspects of one's life.

This is rampant speculation (take with a grain of salt), but do you sit a lot?  If you slouch a lot while sitting you may have impacted your back and hip flexibility, giving you a more rounded back riding position and a shorter reach.

As a final aside if you carry a load on the bike, shifting the pacement of the load ahead of the handle bars can return some of the handling characteristics.


Track cog threading or lockring threading? On the website of a wheel manifacturer, I can find the following specs about the cog compatibility of their track wheels:

  Our track hubs are then compatible with threaded track cogs of Shimano 1.29” x 24 specification.

Is this possible? I am skeptical, because I can't find any cog that has this kind of threading. For reference,

EAI cogs specs show "standard 1.370"x24tpi English threading"
Shimano cogs specs say "ISO 1.375" x 24 tpi"

I suspect the specs on the track hubs refer to the lockring threading instead, because that's the only measure I can find through a Google search that actually corresponds, see https://www.worldwidecyclery.com/products/shimano-dura-ace-track-cog-lockring-1-29-24-tpi-left-hand-thread

If I am right and that's the case, what's the threading on the track hub I should assume for the actual cog?

You are correct, 1.29 inch is the lock ring thread. The ISO thread for cogs is  1.375 inch, and almost all manufacturers use it. The other choice is Italian thread, which is 35mm * 24 tpi (note the mix of metric and imperial measures). This is 0.2mm larger, so in practice they can be mixed.


How can I inflate a tire to the correct pressure? I have a 700 x 38c tire with a Schrader valve I just did a puncture repair on. The recommended pressure for the tire is 75-100 psi (520-690 kPa). I would normally just inflate the tire until it felt about right, but since I had recently purchased a digital tire pressure gauge for my car I decided to use that.

I pumped it up to what I thought was about the correct pressure then checked it using the gauge and it was only at 25 psi (170 kPa). I continued inflating the tire with my hand pump until it became difficult to continue adding more air and it was still at only 37 psi (250 kPa).

I just don't see how it would be possible to inflate it to anywhere near the correct pressure.

According to the label, the gauge is also suitable for bicycles and has a range up to 100 psi (690 kPa).

One term: Mechanical advantage.

You need a pump with the correct mechanical advantage. In the case of an air pump, the size of the piston defines how fast it does its job and how high a pressure you can put into a tire.

Let's say your pump has an effective piston area of 1 square inch (6.5 cm²). That would mean that in order to pump 100 psi (pounds per square inch; 690 kPa = 690 N/m²) you would need to exert 100 pounds of force (or in SI units, 690 kPa * 6.5 cm² = 450 N) onto the pump.

A pump with a smaller piston area will give you an advantage, requiring you to push less hard in order to achieve the same pressure inside the tire, but it also will be slower, as every piston stroke will push in a smaller air volume.

That's why there are some pumps better for low pressure, high volume (like fat MTB tires) and other are better for high pressure, low volume (like skinny road tires).

There are also some pumps with dual mode. They have a mechanism to switch from high volume/low pressure to low volume/high pressure.

The other parameter of a piston is its travel (length of the stroke). A pump with small piston can be "faster" if it has longer stroke, as each stroke will push in more air.

A 700x38c tire is usually wide enough that can be used at lower pressures (I use a set of those and keep them between 40-60 psi (280-410 kPa). Remember most tires have a marking stating the maximum pressure, not necessarily meaning that you must use that pressure. You have to consider your weight, the desired comfort, and the quality of the roads you use.

If you have been setting your tire pressure by hand, and have got good riding performance/ride quality/comfort, and have not had pinch flats (snake bites), then most surely, that pressure is the right one for you on that bike.

If you seriously need to be able to pump your tire higher, consider investing in a pump better suited for higher pressures.

A track pump is the best option to have at home or carry in the car, as it is big and allows you to apply all of your weight to it, they are more comfortable to use and may have an integrated pressure dial. A hand pump is more oriented to be an emergency device to get you out of trouble in case of a flat.

Just in case: Have you calibrated the gauge? If not, compare it with another measuring device. Take several readings to check whether it is giving you the correct reading.