I have a Stronglight 100 5 arm chainset in which the left hand crank repeatedly lossens when I pedal.I have a square taper bottom bracket which is presumably more robust than the alloy crank-arm.Therefore I assume the crank has been damaged at the contact point with the bottom bracket,anbd that a new arm is needed(170mm).
I would like to attempt a repasir if any construtive suggestions can be made eg cleaning contact points with emery paper.All ideas welcomed.
Thanks
Loose crank(left-hand)
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simonineaston
- Posts: 8941
- Joined: 9 May 2007, 1:06pm
- Location: ...at a cricket ground
Re: Loose crank(left-hand)
The retaining bolt's supposed to be tightend up pretty firmly... what sort of torque are you applying to the retaining bolt?
S
(on the look out for Armageddon, on board a Brompton nano & ever-changing Moultons)
(on the look out for Armageddon, on board a Brompton nano & ever-changing Moultons)
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Mike Sales
- Posts: 8355
- Joined: 7 Mar 2009, 3:31pm
Re: Loose crank(left-hand)
mumbojumbo wrote:I would like to attempt a repasir if any construtive suggestions can be made eg cleaning contact points with emery paper.All ideas welcomed.
Thanks
I does sound to me as if those contact points are damaged. Inspect the inside of the crank taper.
I once succeeded in getting a crank, Stronglight as it happens, into usable shape.
I filed the contact surfaces to remove the damage. The crank then went on further and I had to file some off the inside face.
This is a crude bodge, but, if like mine, the crank is u/s you have nothing to lose.
It's the same the whole world over
It's the poor what gets the blame
It's the rich what gets the pleasure
Isn't it a blooming shame?
It's the poor what gets the blame
It's the rich what gets the pleasure
Isn't it a blooming shame?
Re: Loose crank(left-hand)
I successfully bodged a damaged crank using a thick aluminium foil shim from a pie tray. After eating the pie of course. Wrapped a layer around the square taper then tightened the crank back on. 
Peugeot 531 pro, Dawes Discovery Tandem, Dawes Kingpin X2, Raleigh 20 stowaway X2, 1965 Moulton deluxe, Falcon K2 MTB dropped bar tourer, Rudge Bi frame folder, Longstaff trike conversion on a Giant XTC 840, Giant Bowery, Apollo transition. 