Crank Slipping
 

So the last few days I've noticed my right crank slip when I'm either pushing hard up a hill or applying lots of pressure when descending a hill. There are no unusual noises being made and the crank still turns smoothly. Any ideas on what the problem could be and the remedies for it? Thanks.

Have you checked the chainring bolts?

I had a similar problem after putting on a new chainring. Turns out the chainring bolts were coming a bit loose after riding, allowing the chainring to move on the cranks a bit. Make sure those suckers are tightened down hella, and make sure your chain is tight enough.

Sounds like a good ole loose cog n' lockring. If so, you should probably check your hub for stripping

^+1. or just check to make sure that they're tightened.

I had that problem, too, but then found out that if the recesses for the bolts aren't facing the backside of the bolts they can wriggle out pretty easily. Just flip it around and the problem is solved.

loose cog and lockring, thats my bet

I had the same problem when I got my bike, and I would of sworn it was my crank, but it wasn't. Just take it to a bike shop and have them tighten the cog and lockring. Then sprint real quick near the shop and don't apply any back pressure at all it. Hopefully you have a front brake or a steep hill near by. Then tighten it again. Hopefully you have tools to tighten the cranks if not get some.

OR!
Rotafix the cog on and tighten down the lockring/have the LBS do it if you dont have a spanner.

Thanks for the replies. I checked and tightened what I could and it seemed to help. I don't have the proper tools for the cog and lockring so I'll stop by the LBS and have them check those out too.

^ Try and find a shop that has experience dealin with trackos n fixes.

lockring tool = best money spent! rota-fix knowledge is priceless

Yes indeed. Maybe look into getting a lockring tool with a chainwhip as well, both prove to be money well spent and they are often paired together. One less tool to have to keep track of if they are hooked together :)

I know that I say this all the time, but if you're going to ride fixed, you really should have a chainwhip and lockring wrench. Both tools are smart investments that will save any rider money over the long term, and likely encourage them to try new things.

most definitely. They're not that expensive and knowing how to fix your bike is always a useful skill.

Well, you guys were correct. I was just leaving my house and what happens, cog and lockring come off. F**K!!!!! I guess it's off to the shop to get it fixed. And to learn how to fix it on my own.

EDIT: Rotafixed it and it seems to be working fine. I'll keep an eye on it so it doesn't happen again. Thanks again for the tips and info.

Don't buy a chainwhip. Rotafixing cogs on and off takes 30 seconds and is really easy. The only lockring wrench I've used is the hozan one, but it's worked out well for me so far.

That's good it wasn't stripped out.
That's what happened to two left bulletproof crank arms that I used.

That's because hozan wrenches are effing amazing.

is it possible that the cranks will jerk because the back wheel slipped on a rock or something?

i notice it sometimes when i'm on the bike lane where there's lots of pebbles and it feels like the cog slipped momentarily.

if the cog and lockring looks and feels really really tight is it possible that it isnt? i took a lockring wrench to it (not the right size though but it still grabbed like two of the slots) and tried as hard as i could without stripping it (which was still alot of tourque) and it didn't budge one bit.

yeah, your wheel slipped on those pebbles. it feels JUST like as if your cog/lockring is loose just without the pebble/gravel sound

Yeah... I push so hard through the pedal stroke that I always spin out on rocks and gravel...

Ok not really. I do like the success of the rotafix method so far.

I'd get the newer Dura-Ace lockring/chainwhip tool combo - the one with the spring, even highly recommended by the likes of Peter White I believe. It's fairly cheap there, and at Trackstar - I personally got mine from Ben's Cycle (LBS was just too much of hella sticker shock compared to online :()

so this is a common thing? if my cog/lockring are loose i'd notice it all the time wouldn't i? i only occasionally notice the slip from what i think is rocks. especially at school since everything is paved with gravel stone.

a buddy of mine bought a brand new pista and had it slip on the way home. We rode back and had them tighten, that didn't work. Then had them put a better cog on...that didn't work. He returned the bike and said ENOUGH!