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I've bought a secondhand ht2 crank about a month ago but only fitted it a couple of days ago.
Out on the shakedown ride last night and the left arm kept falling off. The pinch bolts are torqued correctly.
So it appears there's some wear to the splines on the arm. What are my.options to.stop the arm coming off? An hacks or bodges?
It’s normally dead. Possibly get away with a new left crank, but you might not
Replacement is necessary I think
Buy a new one.
Sorry, but you've bought a pup.
You can sometimes get replacement non-drive arms, but it's by far a given it will fix it and not all types and lengths are available.
A metal pre load bolt and do the pinch bolts up a bit tighter.
Thanks lads.
If they're worn, one day they will slip. It will hurt, lots.
What spec and size? You'll be amazed what people have kicking around in the spares bin.
There is absolutely no point in havng a metal pre-load cap. The cap is redundant anyway, once you've got the pinch bolts done up. If the crank arm is being held on by the pre-load bolt, then the crank is bin fodder.
Over-tightening the preload cap shags the bearings in no time
There is absolutely no point in havng a metal pre-load cap. The cap is redundant anyway, once you’ve got the pinch bolts done up
Based on experience or what you reckon? It's not an ideal solution but then that's not what this thread is about.
Over-tightening the preload cap shags the bearings in no time
True. Lucky no one suggested doing that 🙂
New crank as suggested above, assuming your BB is spaced out correctly, and not pushing the crank too far out to locate properly.
If the splines are so worn that doing the pinch bolts up tighter dosent work I don't think I would use it. Using a metal preload cap to keep a crank arm on sounds pretty nasty to me!
The crank arm is meant to clamp onto the axle not rely on a little cap to keep it on, plus I guess you have to do it up a lot tighter than it was meant to be tightened if you're using it for that purpose!
Based on experience or what you reckon? It’s not an ideal solution but then that’s not what this thread is about.
The metal cap won't hold a crank on if the pinch bolts don't.
The crank is shagged. If you want a proper bodge a coach bolt through the lot and mind your ankles
If only there was a 'WANTED' section in the new classifieds..............
Drill the arm & spindle and put a roll pin through it.
What crank is it?
I have a surplus 2x SLX crank in the spares box.....
This started happening to my XT crank after about 6 months. Really annoying, was taking a spare pre load cap with me on spins ! As a last resort, before buying a new crank I ended up tightening the hell out of the pinch bolts using a ratchet. Hasn't budged in six months. Might be fun when it comes time to change the chain ring 🙂
There is absolutely no point in havng a metal pre-load cap. The cap is redundant anyway, once you’ve got the pinch bolts done up
Based on experience or what you reckon? It’s not an ideal solution but then that’s not what this thread is about.
The pre-load cap does only that - preloads the bearing. The only thing holding the crank from spinning is the splines, which are torqued together with the pinch bolts.
You might get success from tightening the bolts beyond toque settings, but you risk shearing the bolts, or the crank failing when you land something - which would be very unpretty. Don't risk it.
If the arm spins after the pinch bolts are tight, then buy a new SLX crank. They're pretty cheap.
I have, in desperation at a DH race, wrapped a layer of thick metal foil (not the cooking type!) Around the splines on BMX style cranks which were slipping. Surprisingly it worked for ages... Might be worth a go, but it's definitely a bodge!
I used loctite on mine when the splines were a bit worm and kept coming loose. Solved the problem.
I once stripped the plastic preload star bolt on a pretty new bike and the crank arm kept coming off even when tightening the pinch bolts to spec.
I ordered a metal preload bolt and it solved it so I think it does a bit more than preload the bearing.
I ordered a metal preload bolt and it solved it so I think it does a bit more than preload the bearing.
The point being if it is its damaging everything else.
Been on sram cranks for a few years now, problems solved.
Had this problem once out in Swiss Alps at the start of a holiday, dropped off four times on the same day. Only solution was to buy new at Swiss prices or use an aluminium preload bolt to get by until we got home that the guide found in his spares box. Held throughout the holiday and never got round to changing it. It was still going strong two years later when the bike got stolen.
Shimano Saint cranks come with an aluminium preload bolt.