How do I stop stripping cranks?

[mscalisi]

I think it's strange that you're stripping pedals.

A few things come to mind. It's easy to strip pedals if they're cross-threaded, which usually happens when you mix up left and right. To prevent this, trying getting the first couple theads on the pedal by hand. If you're using a wrench, and getting a lot of resistance, something may be wrong.

Its possible to weaken the threads by overtightening. You shouldn't have to muscle the wrench. It should be just a "little" tight.

Lots of people go huge on their unicycles, and usually many other things break before their cranks get stripped.

Loctite won't hurt, but it shouldn't be necessary.

I didn't see it mentioned elsewhere in this thead, the right pedal theads on normally (righty-tighty), but the left pedal theads on the opposite direction. (your bike shop should definitely know this)

[tambourineman10]

Thanks for all the advice. Last question, should I try to get stronger, pricier crank arms or the same aluminum torker ones (and use loctite).

[Chrashing]

I don't think it's matter of stronger cranks.

What I do is, torque the crank bolts, ride few minutes, then torque, ride again, then torque, then after a longer ride torque again. That will get the cranks seated and tight. Still, it's important check once in while.

Me, I torque to 50 foot pounds, this is higher than most people admit to, but I've changed many cranks and never had a problem with this damaging the hub.

[Unicorn]

I have a KH24" 2007 and I put Bontrager "Big Earl" pedals on it. I do a lot of MUni with it and a fair amount of trials. The right pedal only, started loosening every couple of days. Especially when I was doing practice sets of stairs or rock climbing or just riding backwards for a kilometer or two on dirt roads after a MUni ride. I would feel the loseness and immediately tighten it back up. I got sick of it and cleaned the threads, both inside the crank and around the pedal, real good with dish detergent a a tothbrush. I then put the blue locktite in and never had another problem with the pedal unscrewing. I have not checked this out with material engineers but common sense would tell me that with the loctite there would be no need for grease because the loctite is going to give a thin seperation between the two metal parts. Please correct me if I am wrong. I have not put loctite on the left pedal because I never had a problem there. I still do a lot of hoping on stairs and rocks and backward riding. I also do a lot of direction changes durring skill building sessions and don't have a problem with either of the pedals. ( the right with the Loctite and the left with grease. My advice is that Grease is the best but backward riding and jumps create additional problems that bicycalist don't experience. Therefore only if you have a problem use Loctite.


Unicorn

[feel the light]

I knew it
I am tempted to take a pole !
I think maybe we tighten left threaded pedals less torque. Or we are pedal handed, like right or left handed.
It has always been the left pedal that strips this way, that I have seen.
It is not always worn or poorly fitted uni's that have this trouble. Both my new KH's have had this trouble.
Most likely because I, rather than Kriss, installed the pedals.
Anyway, a tube of loctite is a must for any hack mechanic, at 3 dollars USA.

[feel the light]

I just tightened the pedal more.

[feel the light]

Are you left handed, or off footed, sort of? You are messing with my comprehensive theory of pedal problems!

[feel the light]

It costs 3$/tube and has no down side. On cheaper uni's with softer metal I say use it, by the time you feel the flex, the damage is done.

[Unicorn]

No, I am not left handed. The Bontrager pedals were on my Onza before hand and I did not have a problem with the right pedal coming loose. Also before I had the Bontrager pedals on I had Welgos for about 8 months with no problems. It could just be an issue where the insert in my particular KH crank is on the larger side of tolerance and the pedal threads on my particular right pedal are on the smaller side of the tolerance. Keep in mind that I do a lot of Jumping and backward riding. That is a dedly combination for pedals.

Unicorn

[john_childs]

Originally Posted by Unicorn

I have not checked this out with material engineers but common sense would tell me that with the loctite there would be no need for grease because the loctite is going to give a thin seperation between the two metal parts. Please correct me if I am wrong.

That is correct. The Loctite will act as a lubricant while it is wet. Once it is dry it will continue to protect the threads from contamination. If you have to remove the pedal you'll need to clean off the dried Loctite and reapply fresh Loctite.

[mcnuggets300]

does it mean the crank/pedal is being stripped when there are sharp shards forming around the hole where the pedal meets the crank
when i replaced the peds, i thought it best to file these down, but they're back again

[tambourineman10]

yeah, I have a bunch of those shards around the stripped pedal and a few are starting to form around my good tight pedal. The LBS said they were signs of the stripping.

[john_childs]

Originally Posted by tambourineman10

yeah, I have a bunch of those shards around the stripped pedal and a few are starting to form around my good tight pedal. The LBS said they were signs of the stripping.

It can also be a sign of the shoulder around the pedal threads eating into the metal of the crank. With many cranks being aluminum and softer than the pedal spindle, it is quite possible for the pedal to eat into the crank that way. You'll see a worn area and indented area around the pedal threads on the crank.

That's not the same as signs of stripping the actual threads. So you'll want to figure out which it is.

One of the reasons for using grease on the threads is so the threads don't grind and wear down (or get shaved off) as the pedal is tightened down nice and tight. If you're not using enough grease on the threads you may find little shavings from the threads that have been worn or shaved.

[tambourineman10]

well the new cranks are on (have been for some time) and are loctited. The pedals aren't giving me much trouble but there's been a ton of general creaking, especially when idling or switching between riding and hopping. I've been tightening up the bolts attaching the cranks to the hub every 15-20 minutes which seems to keep the creaking to a minimum. Some of it sounds like it could be coming from the spokes, but since the tightening is helping I'm assuming it's mostly the cranks themselves. In any case I've come to the conclusion that I can't really go much farther on my Torker CX and the time has come to get a new uni.
I'm planning on getting the 20'' KH trials uni from AE bikes since I should be able to afford one by the time they get them back in stock, but wanted to get some input. I'm not very good at trails at the moment, mostly because unicycle failure has kept me from practicing alot recently, but I think that's the direction I want to go in. Also, the seatpost on the KH is 300 mm and I'm 6' 4''. Will that be an issue?? I know the CX I have now has a 400mm seat post although I ride it pretty low. Anyway, are there other unicycles more appropriate for me that I should be looking at?