Lateral movement of bottom bracket

[TheBALDpuma]

I've got a basically new bike (ridden it half a dozen times) with a prowheel cranks and bottom bracket.

There's a tiny amount of movement of the cranks through the bottom bracket if I push left to right. Maybe half a mm. This is the first time I've had these style cranks and BB but I'm assuming this isn't right. I've seen a few guides that show you how to adjust this in certain circumstances.. https://www.parktool.com/en-int/blog/repair-help/b... but, I don't have a preload ring and can't seem to find a guide anywhere how to do it on mine.

Can anyone help?

[irc]

Any pics? Is it possible to assemble that style of crank without putting the adjustment ring on and losing the ability to fine tune the adjustment?

[TheBALDpuma]

[irc]

I take it these cranks aren't Hollowtech 2 style where the tension is by a ring inside the non driveside crank arm. As per

https://www.youtube.com/watch?v=W3-c8tS12Ko

[BOR]

The black ring directly against the chainring looks suspiciously like a preload ring.

Try and rotate it to take up the slack. There might be a grub screw in there somewhere, which you might need to slacken first.

[irc]

Seems a weird design having the preload ring beside the chainrings which make access harder. Usual seems to be non driveside as per.

https://www.youtube.com/watch?v=OjE1YMj9Al0

[TheBALDpuma]

BOR said:

The black ring directly against the chainring looks suspiciously like a preload ring.

Try and rotate it to take up the slack. There might be a grub screw in there somewhere, which you might need to slacken first.

I had the same thought but it doesn't look like it... It wouldn't move without taking off the crank arm/chain ring...



I think irc might have the solution with the hollow tech 2 design. I don't have the tools though so maybe a trip to the bike shop!

[BOR]

Yeah, the black ring is probably just to hold the chainring on.

Maybe the chainring is loose? Sometimes happens to me with my direct mount race face crank.

Otherwise, the non drive side crank might simply need to be loosened, then cleaned/refitted/tightened????

[TheBALDpuma]

BOR said:

Yeah, the black ring is probably just to hold the chainring on.

Maybe the chainring is loose? Sometimes happens to me with my direct mount race face crank.

Otherwise, the non drive side crank might simply need to be loosened, then cleaned/refitted/tightened????

Nah it's not the chainring, the whole unit is moving through the bottom bracket

https://youtube.com/shorts/kLDYQRVP3iY?si=oCl8-jnu...

Edited by TheBALDpuma on Monday 29th January 07:42

[bobbo89]

These not just the same as Shimano cranks? If so it should just be a case undoing the two non-drive arm bolts, tighten up the preload adjuster then tighten the crank bolts back up.

No idea what tool you'll need to add pre-load with these as until now I'd never heard of these but I'd have thought it'd be something similar to this...



If that doesn't work then it might want an extra BB spacer non drive side but that'd be a last resort job.

[TheBALDpuma]

bobbo89 said:

These not just the same as Shimano cranks? If so it should just be a case undoing the two non-drive arm bolts, tighten up the preload adjuster then tighten the crank bolts back up.

No idea what tool you'll need to add pre-load with these as until now I'd never heard of these but I'd have thought it'd be something similar to this...



If that doesn't work then it might want an extra BB spacer non drive side but that'd be a last resort job.

I think you're right but I dont have the tool or a torque wrench delicate enough for bikes so it's booked in at the shop now

[TheBALDpuma]

All sorted now and a really easy job. It just needed tightening up into the bearings. And all I would have needed is an allen key. No special shimano tools, just loosen the pinch bolts on the non drive side, squeeze up the allen key bolt through the BB until there's no movement, then torque up the pinch bolts again. Simple. Well it is with you know, haha.

[irc]

Makes sense having an Allen key adjuster rather than the Shimano tool. Though an advantage of the Shimano version is that it discourages over tightening.

[bobbo89]

Yeah the whole point of the Shimano design is that you only torque it finger tight as that's all it needs.