torque crank bolts to... ?
 

Hey guys sorry I didn't search, but I need a quick answer and sifting through search results usually takes me longer than just asking a simple question.

I have a cup and cone, loose ball, BB with a square taper campy spindle on my peugeot fixie conversion. Bulletproof bmx cranks (budget reasons).

What is the proper tightening torque for the crank bolts? The cranks just started to get a tiny bit loose, hopefully I caught it before the cranks have been irreperably damaged. I originally tightened the bolts as tight as I could get them with a 3/8" drive wratchet wrench, but I'm guessing that's not tight enough. I have a 1/2" drive torque wrench. What's the proper torque to use this time?

Mac

Sometimes the cranks loosen on the spindle after you initially tighten them and ride for a bit. I've heard that this is normal and also that it isn't... If I were you I would just tighten the hell out of them again and watch for loosening.

if the hockeyteeth's solution didn't solve your problem, I wonder if the taper of the spindle is the same as the crank's one.


is both of your crank loose?

german torque specs: gootentite.

+1. for about a week i carried a crank wrench with me to tighten the bolts after rides. longer than i needed to, but it gave me peace of mind to tighten the things down.

I am a little worried about this; I read a little about it and it was always in the back of my mind when I put the bike together. I could never get a definative answer whether or not the bulletproof cranks and campy spindle had the same taper. They seemed to fit together ok, but I don't know how "poor" the fit should be if they are incompatible. Would it have been grossly obvious if they were?

Mac

Bulletproof and Campy don't mix. The damage won't be obvious until after a few hundred miles.

Torque = tight as hell.

all your base are belong to us

How about a spindle beer can shim? that's one of those things that I've always thought to try, but never actually done, because I can't imagine it working. But I'd like to know.

Torque values for crank bolts are manufacturer specific. Pretty much need at least 300 inch/pounds and most are spec'd higher than that.

Theres some basic values here:
http://www.parktool.com/repair/readhowto.asp?id=88

Damn.

The problem is fixed for the moment. I torqued both crank bolts to 32.5 ft-lbs.

Also: when I got down there to really inspect things as I did the crank bolts, I noticed the adjustable side of the BB cup had come loose, about an eighth of a turn. The cranks were a little loose, but it turns out I was also feeling a little play in the BB itself. So that is now also fixed, we'll see how long it all lasts.

Mac

damn, should've read the OP more closely.

Achtung! Keine Gebulletproof Crankentorquen mit die Campenbotzombrachet! Geblinkenflashen und Gespitzensparken!