I forgot to tighten the pinch bolts on a HTII chainset and it slipped round the splines when i rode it.

I’ve refitted and tightened and had a brief ride in some high gears to try and provoke it.

Seems ok, but should i trust it? Don’t want to get caught out miles from home.

Did the exact same about three years ago on a home crankset. They’re still going strong with no issues

Never seen one slip round. I’ve had one fall off before.

I’d check the splines carefully and if undamaged Id ride them

Pop the cranks off, and take a close look at the splines and in particular to see if any material has been removed from either part. With the pinch bolt fully loose, the crank arm should just “Open up” and slip relatively easily around over the splines without too much damage. If the bolt was tight, but not tight enough, then there is a chance the splines will have been damaged. It should be obvious if there has been damage as the “swarf” should be jammed in there still!

If it came loose and just slipped off the splines then that sounds like nae bother – that must be the case as if you’d really mashed the crank round the splines you prob wouldn’t be able to re-fit it, not so it worked anyhow.
If it feels solid, no play then I’d go ahead with it.

I had some XT cranks that came loose on a ride. I tightened the pinch bolts up but they just kept coming loose and I had to stop using them.
I’d had them a few years and they’d seen plenty of use.

I’ve done it on a road crank. nipped up the pinch bolts, it was fine.

Yep, that’s it. The pinch bolts were totally loose (road crankset) – I’d preloaded the bb with the top hat cap, but must have been distracted before tightening the pinch bolts. Its not that they weren’t tight enough, I just hadn’t even put an allen key to them.

A fair bit of metal dust but as I say, it seems fine now having tightened it properly.

Chances are the Ali crank arm splines will be damaged rather than the steel axle so a none driveside crank arm would be an idea, I got an XT one a few years back, can’t remember how much but must have been reasonable if I bought it. Same thing happened to me as Simon, the cranks are still going strong.

I did my xtr960 ones about 4 years ago.Bit of nifty work with a file to clean up the splines and they’ve been fine (I use an alloy pre load bolt now though!!!)

Well, I did chaingang tonight and it seemed fine. One of my shifters slipped on the bar instead. Balls.