Chain Ring Bolts

womack

Hi all. After a few years of riding an old heavy (and too big) steel number I decided to buy an aluminium frame / carbon fork frameset and transfer everything over.

This is a first for me but In no hurry, have other bikes, so far fitted BB and put chain set on.

The two outer chain rings were well worn so ordered new and changed.

My question, sorry for the delay, is it possible to overtighten the chain ring bolts. There is a distinct "out of true" so to speak, between the outer two rings when you spin the chain set.

There is a 1.2 mm difference in the gap between the rings where they are bolted together as opposed to where they are not bolted if that makes sense which leads me to believe I may have over tightened them.

Any thoughts / knowledge gratefully received. Thanks in advance.

rafletcher

Sound like either the new rings are bent, or you haven't seated them properly on the spider. You'll not overtighten the bolts enough for that level of distortion.

womack

Perhaps I'll loosen them a bit, try to reseat, loosening and taking the tension off the middle ring may tell me if it is distorted from new if it still looks distorted with no tension on it.

ed1973

Be careful tightening up chainring bolts I found out through experience that going at it like a ham fisted gorilla can strip the threads on the chainring. And at £65 for the 105 outer ring, it’s only a mistake you want to make once. Get a torque wrench, best bit of kit you’ll ever get!

brundonbianchi

womack said:

Perhaps I'll loosen them a bit, try to reseat, loosening and taking the tension off the middle ring may tell me if it is distorted from new if it still looks distorted with no tension on it.

Don’t forget to tighten them and torque them up correctly either. Pick a bolt, tighten it a bit, then go to the bolt opposite to it, and tighten that a bit, then the bolt adjacent to the first bolt, then the one opposite that one. Repeat tightening them in that order bit by bit, until they reach the correct torque. If you can, use a proper torque wrench. I’m assuming you weren’t just tightening them ‘around the clock’ that’s not ideal.

womack

Cheers Ed, I have a torque wrench but rarely use it!!
Anyway I slackened them all off then re tightened gradually and alternatively (rather like doing a cylinder head on a car)

Whilst I was at it I re positioned the chain set on a different face of the BB spindle and any wobble / misalignment appears to have gone.

Hopefully job is a good un!

womack

brundonbianchi said:

womack said:

Perhaps I'll loosen them a bit, try to reseat, loosening and taking the tension off the middle ring may tell me if it is distorted from new if it still looks distorted with no tension on it.

Don’t forget to tighten them and torque them up correctly either. Pick a bolt, tighten it a bit, then go to the bolt opposite to it, and tighten that a bit, then the bolt adjacent to the first bolt, then the one opposite that one. Repeat tightening them in that order bit by bit, until they reach the correct torque. If you can, use a proper torque wrench. I’m assuming you weren’t just tightening them ‘around the clock’ that’s not ideal.

No, not around the clock, 40 years in the motor trade taught me sequencing when tightening bolts.

MattFalle

remember that if there is a sticky out grub thing that goes behind the crank arm to catch the chain should it fall off.

ed1973

womack said:

Cheers Ed, I have a torque wrench but rarely use it!!
Anyway I slackened them all off then re tightened gradually and alternatively (rather like doing a cylinder head on a car)

Whilst I was at it I re positioned the chain set on a different face of the BB spindle and any wobble / misalignment appears to have gone.

Hopefully job is a good un!

Glad to hear it.

womack

MattFalle said:

remember that if there is a sticky out grub thing that goes behind the crank arm to catch the chain should it fall off.

Yeah, got that. Next new job for is forks and headset. As my nain used to say " Everyday is another day at school"