Bicycle Mechanics - Fear of shearing crank bolt

I sent my new bike that has a FSA carbon comp crank and American Classics ISIS BB back to the LBS cause it was making noise and the crank bolt would loosen up and the crank start creaking like every other ride.. The shop said that removed, cleaned and reseated the BB and crank.

So I got it back, and, well the tapping & clicking from the BB has stopped, but dammit, after like 40 miles, pushing down on the left crank arm makes noise.. the kind of creaking noise from loose crank arm.

I have a torque wrench, it's a Great Neck one. not a park tools, but I trust it cause I use it for jet ski repairs. and I tonite, I took my 8MM to the bolt and torqued it down. it probably went 1/2 revolution, and might go more, but i'm really scared to torque it more... I'm afraid of sheering the bolt. Should I try to tighten it up more I would suspect that the LBS shop would have torqued it good...

But why is the crank bolt keep coming loose on this new bike? Can I do anything to the crank bolt to keep it tight? and how, if the BB or anything is shot on it, can I get the LBS to warranty the whole thing?

-e

Ideally, one should use a torque wrench on crank bolts, and one should be able to find the appropriate torque specification on the crank manufacturer's website. This is arguably the single most important bolt torque specification for the entire bicycle.

Although I have never damaged a crank, BB, or crank bolt by overtorquing, I did once have a left crank work its way loose as I rode. :o Prolonged riding on a loose crank will deform its spindle eye, to the point that it will no longer seat properly on the spindle, even when torqued to specification. If your LBS is reputable (check this with other local cyclists), bring the bike back and ask them to torque both crank bolts to factory spec.

Id torque specification particular to the BB or the crank manufacturer?

Might want to check the bolt on the off chance it was overtorqued and stretched.
Not highly likely but possible. Might not be obvious except on close exam with a
thread gauge. (been there/done that both on BB bolt and on a QR skewer - not so
good 500miles into a 1500mi tour). Steve

I sent my new bike that has a FSA carbon comp crank and American Classics ISIS BB back to the LBS cause it was making noise and the crank bolt would loosen up and the crank start creaking like every other ride.. The shop said that removed, cleaned and reseated the BB and crank.

So I got it back, and, well the tapping & clicking from the BB has stopped, but dammit, after like 40 miles, pushing down on the left crank arm makes noise.. the kind of creaking noise from loose crank arm.

I have a torque wrench, it's a Great Neck one. not a park tools, but I trust it cause I use it for jet ski repairs. and I tonite, I took my 8MM to the bolt and torqued it down. it probably went 1/2 revolution, and might go more, but i'm really scared to torque it more... I'm afraid of sheering the bolt. Should I try to tighten it up more I would suspect that the LBS shop would have torqued it good...

But why is the crank bolt keep coming loose on this new bike? Can I do anything to the crank bolt to keep it tight? and how, if the BB or anything is shot on it, can I get the LBS to warranty the whole thing?

-e If the BB crank interface is hosed,the crank won't stay tight. The shop could have screwed it up and if you mess with it,they are off the hook.Take it back and make them make it right.

Might want to check the bolt on the off chance it was overtorqued and stretched.
Not highly likely but possible. Might not be obvious except on close exam with a
thread gauge. (been there/done that both on BB bolt and on a QR skewer - not so
good 500miles into a 1500mi tour). Steve


I've tightened bolts on engines and what not... and sometimes, you can tighten a bolt and it can start to feel like its going to stip or it is stretched.. and that's kinda what my spidey-sense is telling me.. but since i'm new to bike work, i'm not sure if it is or it just can be torqued down even more.

-eric

CRAP!
so I took my bike to a better LBS just to check my torque and he said "something's fishy" so proceeded to take apart the BB and check for grease etc.

to both our surprise, the bearings were siezed up in the BB.. so American Classics bottom bracket doesn't have my vote for president..

Anyone recommend any BBs for road cycling? I hear the FSA Ti or Truactiv

I have a truvativ ISIS SL that I put about 300 miles on commuting on a fixed gear...no probs so far. but then again, 300 miles is almost new...

I heard about either getting the Truavtiv or a FSA carbon comp..
Well American Classics will warranty the bottom bracket.. so anyone want to buy a new AC bottom bracket 108MM?