sathor

Got tired of the clicking from my bike when I peddled, especially after getting a new bottom bracket installed from the LBS, and it didn't fix the problem. It got a bit worse, I checked with Sheldon Browns site, ran through the things to try, and it got better (I tightened the crank arm bolts) but still clicked when I was using more pressure.

Anyways, I bought a torque wrench for 40 bucks on sale, and set it to 26 ft-lbs, as per Park Tool's site, and both sides got a fair bit tighter. (I didn't hit the max on the wrench, my socket was a deep well one, and didn't have the best of grips)

So, my question is, should I have been able to tighten the bolts after the bike shop changed my BB, or should I count that as the last straw for using that LBS for working on my bike? At this rate, I will have almost all the tools I could need, but I would hesitate to recommend that place to others for doing service work if that is the result. (Also, is 26 a good amount, or is it too high or too low?)

Drew Eckhardt 

It depends on the crank set. Track down the documentation and use whatever it says, noting that some crank/bottom bracket interfaces (like ISIS) require torque near the high end of the specification for the cranks to come to rest against shoulders on the bottom bracket spindle.

My ISIS crank arms didn't seat right until I torqued them to about 40 ft-lbs with a specified range of 29-43 ft-lbs.

laura*

Yes. As you pedal, the crank arms work their way even tighter onto the spindle. The result is looser bolts. If you keep retightening them, you might eventually split the crank arms.

If you don't trust the tightness of crank arm attaching bolts, you should pull the crank arms off, and reinstall them to spec.

sathor

I might do that, but I don't have the specs for them. I mainly tightened them because ever since I picked it back up from the bike shop it had been an irritatingly noisy crank when getting up to speed. (I did take it from 3 clicks down to one yesterday, and I hope it is down to zero)

If I did split them, I guess it would give me an excuse to upgrade though, right? Also, at 26, when that is near the bottom of the range, is splitting them really a viable thing to worry about, or is it more of a 'once I start, I might keep pushing higher' type of thing?

laura*

The tightening torque isn't the issue - repeated tightening is:

https://www.sheldonbrown.com/brandt/i...ng-cranks.html

sathor

ok..... well, my right one was loose too, so... Tightening them is actually on the 'creaks' page as a way to fix certain noise while pedalling.

All that being said, perhaps that entire crankset is ready for an upgrade anyways later this season.

If i were to order a new crankset, do I have to find a triple that is marked as a 7 speed compatible, or would one marked as 10 speed compatible work?

Retro Grouch 

A bicycle is a simple machine but the devil is in the details.

Crank arms is one thing that I always use a torque wrench on. Lots of mechanics say they have a good enough "feel" not to need a torque wrench but, if left to my own judgement, I know I will always undertorque crank arms. Lots of cranksets use an 8mm allen for the crank arms. If you're using a 6" long allen wrench, you're not getting even close to 30 lb/ft. I've worked in bike shops, however, that actually did that.

Inadequate torque on square taper crankarms will eventually result in the left crankarm coming completely off the bike. When that happens the square hole in the crank arm has been ruined and the arm must be replaced. That happens often enough that bike shops, even bike shops that carry very few spares (and don't own torque wrenches), keep generic crank arms in stock.

26 lb/ft is, if anything, on the low side. I use 30 lb/ft. unless I have specific instructions saying otherwise. 30 lb/ft is quite a bit. Try to imagine a 30 lb weight hanging off the end of a foot long wrench. Done right the first time I've never had to re-tighten a crank arm. If you decide to check yours, loosen the fastener then retorque it to the proper value. If you just try to check it with a torque wrench, you'll actually tighten it a bit extra. Eventually that will result in a cracked crank arm.

Another thing that could be causing the clicking you describe is inadequate torque on the bottom bracket. That generally requires 30 lb/ft too.

sathor

On today's 25 mile ride, the only real noise came form my handlebar squeaking. I looked at them and said scew it, I ain't fixing that. I need to get back onto the porch and lube the chain, the last 5 miles were in thunderstorm.

oh, and I needed a non metric that was near a 14 mm if I remember, I know a 6mm was too small though.