27

There are a couple of things you should consider: Your bike isn't going to care. You aren't going to loosen pedals or cranks spinning in reverse, because you're not applying any load, so there is no force in which to cause precession or fretting. You are getting no benefit (health-wise) from doing so. It might be better not to even bother.


23

I think your pedal is a lost cause. Even if you did get it off in the current condition, reinstalling and later removal will make later-you hate current-you. I would disassemble the pedal from the outside - remove the axle cap, locknut, cone, and bearings, then slide the pedal cage outboard. You may have a second set of bearings inboard, or a bushing. The ...


17

I started getting seriously into bike work circa 2002 and was lucky enough to come across Jobst Brandt's view of the topic around that time. Since then, most of which time I've spent working as a mechanic, I've observed that the Brandtian observations of the mechanical dynamics at hand are wholly correct, but I don't agree with him on what to do about it. He ...


14

That nut was put in the wrong way around. This is what the nut looks like: The hex end is what you should tighten with a approriate socket. This is what it should look like when installed correctly: If it ever get's super tight as it is now, to get it off, the easiest way is probably to cut it with a tremmel and chisel it out. Good luck!


14

Not really. You might want different gears, but probably not fewer. Shorter crankarms give you less mechanical advantage—they're functionally equivalent to being in a higher gear. So you might want a lower gear range to compensate. It is common to express mechanical advantage as "gear inches"—this is (front sprocket/rear sprocket) × wheel diameter ...


13

144mm: supported chainsets such as 52/42 with relatively narrow range freewheels 130mm: allowed a range such as 52/39, as freewheel (then cassette) range expanded 74mm: necessary to add a smaller ring, e.g., 30t on a road triple 110mm: this supports anything down to 33t, hence this was introduced for Shimano FC-R700 around 2005 as their first compact ...


13

Your crank arm is toast. In my experience, if a square taper ever gets loose while riding, even once, it's done. Retightening the bolts buys you a few miles at best but it'll loosen up again before long. I think the connection to lubrication is coincidental. You said the problem started after you applied lube, but that's not true. You did that because it was ...


11

Many two wheel drive mountain bikes exist. Here's one article advertising a new one: There’s been no shortage of attempts to build a workable two wheel drive bicycle over the years, but this latest effort from Double of Japan looks like one of the most compelling yet. https://www.bikeradar.com/news/this-is-a-two-wheel-drive-bike-done-right-sort-of/ They do ...


11

I'm not an engineer or a historian, so I'm going to go off my memory and, where I can find it, companies' stated rationale for making a change. Bolt circle diameter The larger the BCD, the bigger the minimum chainring size. 41 teeth is the absolute smallest chainring you can fit on a 144 BCD. For the 130mm BCD used by Shimano and many third party cranks for ...


11

I would try removing the crank and clamping the pedal in a bench vise. With the pedal pointed downward and held very firmly in the vise, you’d then try to turn the crank clockwise. Otherwise, the specific model of left crank is not essential. You just need it to be a 175 mm Left Hollowtech II crank arm. Some cranks have different q-factors, so you’ll want ...


10

You are undertightening the crank bolts on initial installation. 44Nm or 33 ft-lb work well as generic values for square taper cranks. A basic large beam-type torque wrench works well for crank bolts. If you aren't able to get one, it's safe for basic square taper cranks to reef like mad with something like a 12" ratchet or breaker bar. You'll be ...


9

We can't tell you what upgrades you should make, because we are not you. We don't know what your preferences or priorities are, what kind of rider you are or what riding you want to do (apart from knowing you have a long distance goal in mind). Go ride the bike. Make a training plan for your long distance ride. Go ride the bike more. Figure out what works ...


9

Aluminum has no fatigue limit and thus it is impossible to make an aluminum bike part that won't fail with enough use. Fatigue accumulates with load, not time. Good forged cranks with designs that avoid stress risers in the spider area tend to be pretty good at resisting fatigue failures more or less indefinitely in practice. Weight weenie designs and bad ...


8

You could replace the crank with any Shimano 2x9 crank for a square taper cartridge bottom bracket (with the same chainring sizes are crank arm length or course). If the bike is equipped with an Altus groupset then an Altus 2x9 crank would be a reasonable choice. There is a bit of an annoying wrinkle to this, different square taper crank models require ...


8

No, pedalling backwards is not bad for the bike, or any of it's components in the situation you describe (an urban environment). I base this on my own experience riding various bikes (with derailleurs, with internally geared hub) in an urban environment. As noted in the comments on the question and answers: it ever so slightly increases the chance that your ...


8

Modern cranksets either have 24mm-ish width spindles, or 30mm-ish spindles. DUB (28.99mm spindle) falls into the latter category. GXP spindles (24mm, tapered to 22mm on one side) fall into the former. Almost all press fit bottom bracket shells can take cranks with 30mm or similar spindles. Trek’s BB90 bottom bracket standard appears to be an exception. That ...


7

It might be possible to make a new thread using helicoil. It is a job for a good bike-shop but should be cheaper than a good pair of cranks.


7

It depends. For most gravel bikes it will be an easy, yet expensive, swap. A couple of gravel bikes frames are built in a way that makes shipping a front derailleur as good as impossible. There may not be enough room for the chain stays to clear a second chain ring. What is more, some frames lack mounting positions and the shape or material of the seat tube ...


7

There is one benefit to you as a rider, to continue your pedal stroke while coasting. You look like a bike which makes you safer. I've noticed especially in ebikes that are being ridden like motorcycles, that a lack of leg motion makes the whole bike/rider combo look more static than it is. So by continuing to revolve the crank with minimal effort, you look ...


7

9/16"x20tpi is the predominant modern size, and 1/2" also exists. On bicycles, 1/2"x20tpi is virtually always only found on one-piece cranks, but exercise bikes can do whatever. They are almost certainly 1/2". 1/2" cranks do not typically have enough material to be tapped to 9/16", but they're also not typically a 3-piece design ...


7

I know this situation myself. The pedal shaft is hardened steel. It will win. Taking into account what you tried, expect the thread in the crank to be lost even if you get the pedal off, eventually. So my recommendation: Get a spare left crank from your repair shop. It will save you a lot of time and headache. One more: When mounting pedals, use loads of ...


7

First, just that both say "FSA Road" doesn't mean that they are compatible. The answer is to look up the documentation for the crankset. It's the first Google hit if you search with the name and then look for bottom bracket. It says 118mm (which is unusually long) and JIS. You need a bottom bracket with axle like this. Edit: Looking at the bottom ...


6

Nope, it won't hurt anything. It's unlikely, but the worst case is that you might knock the cable crimp (the cap on the end of that cable) off eventually, which could then cause the cable to fray, which would then eventually need to be replaced. I would try to bend the cable so that it is tucked away behind a piece of the bike frame or the front derailleur ...


6

You've broken your bottom bracket's axle. There is no way to safely reattach, so you're up for a replacement bottom bracket. Ideally you'd install a cartridge BB that duplicates what you have. The crank arm (in your hand) is probably okay to reuse, though have a good clean and a close inspection before doing so. Dings are fine, chips maybe, and cracks are ...


6

A few obvious observations: BCD (bolt circle diameter) puts a limit on how small the chainrings can be. For example on a 110mm BCD the smallest possible chainring is 34 teeth (33 or 32 are possible with some tricks like smaller diameter bolts). You need a certain number of bolts and arms to prevent the chainring from flexing sideways or taco-ing. More are ...


5

Everything looks right. Whenever using a crank puller but especially when it's taking a lot of force, it's very important to have the tool installed into the crank arm with some real torque, not just finger tight and never loose. You can grease the threads if there's roughness. Here with the nutted spindle it's a good idea to start with the puller either in ...


5

SunRace spec sheets show the crank bolts should be M8x1.0. The bolt diameter is 8mm and there is 1mm betwween thread peaks. This size is by far the most common. However there are other standards. Truvativ seems to have the most variations using M8, M12, M15 plus some self extracting bolts. If the bolts starts but binds it is likely the right diameter but the ...


5

What you need to do is look up the total capacity specifications of both your front and rear derailleurs. For a front derailleur the total capacity is just the largest difference between the largest and smallest chainring tooth counts the derailleur can handle. The total capacity is for a rear derailleur is the largest (difference between the largest and ...


5

Probably ISIS splined. That’s the only one with splines of that length with the smooth end. https://www.sheldonbrown.com/bbsize.html


5

It looks like you have a crankset with non-removable chainrings. The 'bolts' you are measuring the geometry of are just screws holding the chainguard on. The chainrings appear to be pressed steel and attached at the crank axle. It's much more likely the pressed steel rings are bent than the bottom bracket axle, so replacing the entire crank is possibly all ...


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