Crank care help needed

I’ve just been reading through the Kris Holm “Unicycle Assembly Instructions” that came with my new uni, and there’s an interesting paragraph at the end that says:

I can see how this would be very beneficial on a trials uni where the wheel and cranks are consistently subjected to load bias, but what about if the uni is used for cruising around town, is it really that necessary? I’m happy to deflate my tyre and rotating it through a quarter turn every now and again, and to tweak spoke tension when needed, but I’m afraid frequently removing the cranks might knacker the ISIS interface. I’ve never done this on my trials bike or heard about anyone doing it. Would appreciate your advice.

Likewise, my cranks have two pedal positions (127 mm & 150 mm), cranks are made of aluminium and pedal axle is steel, so in a friction situation steel wins. Depending on whether I’m riding in town or off-road, I might need to switch back and forth between the two, just wondering if the cranks are really designed to take frequent screwing and unscrewing of the pedals or, rather, whether the dual crank length option is provided for riders to try initially, pick one and stick with it? I grease my threads BTW.

Last question, assuming the answer to the previous question is “yes you can swap out your pedals regularly”, do you guys use some kind of a dust cap to prevent dust from lodging in the unused thread?


On my 19" I didn’t turn the cranks and ended up seeing why it’s recommended, the rim got flatter on the bottom… On a unicycle you don’t do trials on, I don’t think it is that necessary. Rotating the tire is probably a good idea, even if you aren’t idling or hopping a lot, the tire still tends to wear more in certain stops (mostly due to a tendency to do tight turns in certain pedal positions I think). On a bike it’s not necessary, because your crank and wheel positions aren’t fixed together like on a unicycle.

Yes, you can swap out your pedals regularly. If you make sure the threads are clean (just use a rag or similar to wipe any dirt of them), and you don’t cross thread there will be no noticable wear on them. I have seen some people using caps, but most don’t.

For ordinary riding, the advice is over cautious. And what is a "ride"anyway? It may be a mile or 50 miles, on road or off road, fast or slow, hilly or flat. The rider may be portly but powerful, or skinny and weak.

It’s certainly wise to do this routine occasionally, but I wouldn’t be rigorous about the “every 30 – 40 rides”. I give my unis a thorough going over about once a year. However, my KH29 and KH36 have never had their cranks removed, although in both cases the tyre has been off many times for puncture repairs.

In terms of protecting your rim from flattening, that should not happen unless you are doing lots of drops and jumps. In terms of evening out the wear on your tyre, you may prefer to slip the tyre off and move it round 90 degrees.

Every time you disassemble and reassemble any bolted assembly, there is a risk of damaging either the head of a bolt or the thread — worst of all, the thread in the component rather than the thread of the bolt. If you do it too often it may cause wear or fatigue of the bolt or the threaded socket. You need to balance the advantages of the service regime against the advantages of leaving well alone.

As with most things to do with unicycling, there is a strong tendency to overthink things that are essentially very simple. Check periodically for wear or loose bolts and address problems before they develop, but don’t make work for yourself.

Remember that a car or motorbike is working in a harsher environment and under more stress and only needs either an annual service or one every few thousand miles.

I started rotating my cranks because I kept breaking spokes in the bottom quadrant (when my cranks were in my favorite left-foot-forward position) of the wheel.

But it was only one wheel, and I think it was kind of a crappy one (Torker DX). I rebuilt it with new, better spokes, and have never had any problems again, even though I eventually kind of forgot about rotating the cranks. So I guess I would vote: don’t bother.

“Knacker” — nice to see some proper English in the forum.:slight_smile:

If you are using proper spacers there shouldn’t be any damage to your ISIS interface from frequent crank changing, but if you don’t use spacers the crank will tend to go on further each time eventually bottoming out and preventing a good connection.

Having said that, unless you are smacking your rim on stuff I wouldn’t bother rotating the cranks, but would do the tire when you see wear.

Same here, that’s over cautious for a uni that doesn’t get tons of abuse. I only rotate the cranks each time I have to remove them - for instance switching to shorter ones.

Thanks for all your valuable comments. For my 27.5" one I will keep an eye on my tyre and see how it evolves. I think the key is to space the 1/4 rotations as evenly as possible in time, to ensure each quadrant of the wheel/cranks/tyre endures a similar amount of bashing as the other three. How often it’s done is probably not so important as long as the doing happens at fairly regular intervals. Therefore, Kris Holm’s 30-40 cday schedule would certainly achieve the goal of reducing load bias for any rider but may be a little overkill for the casual rider. It does, however, hint at the fact that counting rides is a convenient way to measure riding time for most people.