Bottom bracket/drivetrain problem, advice would be helpful!

[Flandria]

Second problem about the scratching partly solved: I've installed another DS crank and with this one the clearance stays more or less 3mm all the time and it runs smoothly, without 'wobbling'.

So, one of the three arms of the spider is a bit out of place. Since the crankarm is useles anyway, I'm gonna try to 'replace' it with a hammer and vice tomorrow. Otherwise, i'll have to find another crank!

And again, thanks for the infos. I didn't studied a single letter for my exams today but at least i've learnt how to remove cranks and revise bottom brackets

 

[FINNEY1973]

Second problem about the scratching partly solved: I've installed another DS crank and with this one the clearance stays more or less 3mm all the time and it runs smoothly, without 'wobbling'.

So, one of the three arms of the spider is a bit out of place. Since the crankarm is useles anyway, I'm gonna try to 'replace' it with a hammer and vice tomorrow. Otherwise, i'll have to find another crank!

And again, thanks for the infos. I didn't studied a single letter for my exams today but at least i've learnt how to remove cranks and revise bottom brackets

glad your sherlock holmes hat came in useful and you got to the bottom of this problem - also good to see you've got your priorities in order - bikes come first everytime

 

[Tel]

I think you are most likely to find the new crank will be fine, it is likely that your chainwheels are bent. If there is taper wear it is more likely to be on your alloy crank arm than on your steel axle....

 

[Flandria]

Today I've bent the crooked spider arm back in it's old position. Sheldon Brown said to use a vice and an adjustable wrench. After a few attemps, the crank is working in an acceptable way and the horrifying sound is gone!.

But still, I'm going to look for another crank arm to give a definitive solution for the problem.

Thanks for the help!