Hollowtech bottom bracket/crank issue

Dogoid · 21 Feb 2016 at 15:59

purchased a new BB from Ebay, generic Shimano Hollowtech , but it didn't come with spacers so i read up the spec's reg spacers for this standard and the Shimano site says 2 on the drive side and 1 on the NDS, did this but the axle seems to be a short of fitting right through the NDS crack arm.

wondering about the need for spacers? are they needed all the time? it seems to be too much length for the cranks to fit on.

also, the drive side crank doesn't seem to fit flush on the BB bearings. bit of a gap between the spider and BB.

edit. this is for a MTB

can take pic's if needed.

thanks

uv · 21 Feb 2016 at 16:04

Is this for MTB? I've never had to use spacers fitting HT2 on road bikes so far..

Dogoid · 21 Feb 2016 at 16:07

yes , sorry i should have mentioned. you're right, road bikes don't need spacers at all. spacers are needed to correct chain line with having more gears and a different hub.

touch · 21 Feb 2016 at 16:29

2 drive side + 1 non drive side is probably the maximum number of spacers shimano recommend for that BB. The actual number of spacers you need will depend on the BB shell width of your frame and the length of the axle on your crank.

Dogoid · 21 Feb 2016 at 16:58

touch said:
2 drive side + 1 non drive side is probably the maximum number of spacers shimano recommend for that BB. The actual number of spacers you need will depend on the BB shell width of your frame and the length of the axle on your crank.

thanks for that , i think I'll go with no spacers at all , as i had ridden that way before i knew about needing spacers and shifting was fine.

still worried about the small gap between drive side crank and BB.

any ideas?

Jonny ///M · 27 Feb 2016 at 18:43

If it's a mountain bike with a mountain bike chainset then you need 2 drive 1 non drive for a 68mm shell.

1 drive side spacer if it's a 73mm shell or no spacer if you have an e type front mech/chain device backplate.

Assuming it's a threaded BSA frame.