Miche Primato Cranks Unscrewing Themselves

Does anyone know how I can stop my Miche Primato cranks unscrewing themselves from their Miche bottom bracket/Miche bottom bracket unscrewing itself from BB thread?

I think it's inevitable because of the way the threads on the bottom bracket shell match the threads on the bb itself; it just happens as you rotate the pedals. I spoke to a mechanic and he said it was an inevitable problem but I figure there must be a way to solve it. Or am I doomed to perpetually having to adjust/tighten the bb and/or the cranks themselves?

I've done a search on this forum but I don't think anyone's asked this question before. Will check on sheldon also. But the problem must have happened to anyone who uses the Miche Primato crank with this BB thread so thought I'd ask if anyone had the same issue and how they solved it?

I'm loath to ditch the Primato cranks as they're great otherwise. But this problem is pretty annoying. Reckon I've got a shot at getting a full refund from the shop (a chain shop not a sole trader so feel way less guilty) I got them from given that they fitted the cranks/bb, knowing that they would inevitably unscrew themselves in light of my BB thread, and only explained this to me a few weeks later. If I'd been a half-decent mechanic sure, I'd have been able to spot the problem immediately myself, but I don't think that argument gets the shop off the hook...

I've got the same crank and bb and not had any problems

Sorry, doesn't help much....

aren't these the adjustable BB's. so i assume like these royce ones, so you need to have a lockring either side to bind it to the BB shell?!?!?

also you can't blame the shop, be a man and take it on the chin. learn from the experience and do something about it.

ihatelaw Does anyone know how I can stop my Miche Primato cranks unscrewing themselves from their Miche bottom bracket/Miche bottom bracket unscrewing itself from BB thread?

Do you have both these problems or just the one? Cranks don't unscrew themselves. If the cranks are getting loose they weren't installed properly to begin with.
Were they greased lightly and tightened with correct torque?

As for the Italian threading: http://yarchive.net/bike/bottom_bracket_threads.html

Have you (or the bike shop) but the BB in the wrong way round by any chance? I thought the drive side would be reverse threaded so that it would tighten rather than loosen when pedalling. Or am i being a retard?

both of mine did it for a bit when i changed the bb's(to shimano), i did get pissed off with having to tighten up the bolts, but now it appears to have stopped and has been solid for a few months.

asm Have you (or the bike shop) but the BB in the wrong way round by any chance? I thought the drive side would be reverse threaded so that it would tighten rather than loosen when pedalling. Or am i being a retard?

Italian threaded: http://www.sheldonbrown.com/bbsize.html#threading

thanks for the links - just the ticket.

nb. yeh I had both problems. Cranks were improperly installed but are fine now. Bottom bracket issue appears to be an inherent problem from this reading material. The first sheldon brown link was great, if depressing. I did not realise there were so many problems with the Italian thread.

Shimano for me, Shimano for you
We all like Shimano coz it's not poo.

i considered putting that on my facebook "favourite quotes" section but decided ultimately to leave "it can't be rape if TWO men say she consented" in place.

if its broke you need more gaffa tape

like, obviously

dude

i had the same problem, i swapped to a campag chorus bb which has a flanged cup on the drive side, it's a lighter bb and uses the same tool as the miche so easy to swap without buying 2 tools*

*it's the splined tool that fits record and chorus the other campag bb's are different

its all about phil wood, though their steel bb is as heavy as my frame...

chris crash if its broke you need more gaffa tape

+1 for gaffa tape!
there's not a problem it can't solve...

Poverty? If only gaffa tape was edible.

It's not edible? :S

want to eat? quit art and do something useful

loctite loctite loctite! :) (and this time I am right!)

chris crash want to eat? quit art and do something useful

hehe! says the messenger, touche :O

I agree with Haj- clean and degrease,then start ' loctite-ing ' . Also, if it's going to be a fairly permanent set-up, the other famous 'ite', Araldite, will stop most things unscrewing, and still let go with a good warm-up if you really need to get it off again.