misbehaving cranks

feetabix · Mar 31, 2009

hi folks....i am having a problem with my non drive side crank loosening during riding.it is a 93 xt tapered crank running on an alloy axle.ive tightened it up and nothing seems worn.any ideas on solving the issue???

Xesh · Mar 31, 2009

Have you tried loctiting the bolt? If that doesn't work then your crank taper is worn. You can tell quite easily if it's worn. It has to be a perfect square. If there's any deformation at all then that means that it's worn.

feetabix · Mar 31, 2009

Xesh":3118ucmr said:
Have you tried loctiting the bolt? If that doesn't work then your crank taper is worn. You can tell quite easily if it's worn. It has to be a perfect square. If there's any deformation at all then that means that it's worn.

.....i had considered that but was warned off it by a bike mechanic friend....i will give it a go without using too much of it,see if it makes a difference

Xesh · Mar 31, 2009

There are different grades of loctite. Some will set like cement and if you use the wrong one it'll cause more trouble than it's worth.

The loctite that I use is Loctite 242. It's blue and about low to medium strength.

Inigo Montoya · Mar 31, 2009

what kind of crank bolt do you use? never heard of a bb with an aluminium axle. what brand/model is the bottom bracket? for how long are you using that setup already?

feetabix · Mar 31, 2009

yeah,sorry,the axle will be steel.its on a klein attitude,92ish in date, that i recently put together.....i assume it is the original axle.i have ridden it four or five times now in anger over the past month and despite applying an appropriate amount of torque to the bolt cant get it to remain put,resulting in the usuall creaking.once retightened the creaking stops until the bolt works loose again.....the crank looks visually fine.....i considered the loctite thing but wanted to canvass opinion before leaping from frying pan to fire.....daz

pete_mcc · Mar 31, 2009

I don't know much about Kleins but did they ever come specced with Campa compatible bottom bracket axles to match the campa groupsets that some team bikes seemed to have around this time?

Personally though my money is on the crank. Unfortunately it's a vicious cycle as if the crank becomes loose then the BB will wear the crank taper more and so when you tighten it up again it will become looser quicker, then cause more wear on the crank.....

feetabix · Apr 1, 2009

hmmm....i dont know about the campag thing but i do remember a lot of pics of that period showing the bike specked with campag kit,did campag use different bb axles to shimano then???i will try the low strength loctite to see what happens,if it doesnt work then its back to ebay for new cranks!!!......all part of the fun!!!thanks for your time replying chaps....d

Xesh · Apr 1, 2009

feetabix":1eap74t7 said:
.....did campag use different bb axles to shimano then???.....

Campag BB axles are usually slightly different in length but, most importantly, they have a slightly different angle of taper on them. It's not enough to be able to see it but this sounds like what is happening with your BB. If you can try to get an axle that you know is definitely Shimano compatible.

hamster · Apr 1, 2009

The taper angle is the same but the tip is thinner on a Campag BB. As a result a Shimano crank fits deeper onto a Campag BB - and may be so far on that the bolt won't be tight onto the crank even when fully screwed in.

Usually the problem is fitting Campag cranks on Shimano BBs as they only just fit on to the tip of the BB taper.

misbehaving cranks

feetabix

Xesh

Senior Retro Guru

feetabix

Xesh

Senior Retro Guru

Inigo Montoya

Senior Retro Guru

feetabix

pete_mcc

feetabix

Xesh

Senior Retro Guru

hamster

Retro Wizard

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