Hi,

I have a Spesh FSR120 (first year model) frame that I'm re-building. The BB needs replacing after being neglected for a number of years.

The BB has 3 black plastic spacers ….. question, is whay side do the spacers go? All 3 on the drive side leaves the BB thread rather short, so is it 2 on drive and 1 on the other side?

Help and advice appreciated.

Thanks,

I've got 2 drive side and one the other.
They are for the 68mm BBs to get the chain line right, (not sure what it will be on yours but mine is something like 50mm)

68mm shell: 2 on the drive side, 1 on the other (unless you have a bb mount front mech, in which case this takes the place of one of the drive side spacers).
73mm shell, just one on the drive side.

Depends on your chainline and whether the cranks will '****' the chainstays, mine is a 50mm chainline with a 73mm shell, I have 1 spacer on the non drive-side and 2 on the drive-side, there should be no more than 2 x 2.5mm spacers on either side. Try and torque it up too, don't just hang off it.

If you go by the shimano install guide, 73mm shells require only 1 spacer on the driveside. If you've currently got 3 on the bb, the left hand crank is not on the axle enough!

Hmmmm. I have 3 spacers from when the bike was new – this is the first time I have changed the BB – Race Face BB lasted @ 4 years!

Does it make a difference that the replacement BB is a FSA 70/68mm BB? Haven't seen these sizes mentioned above.

Thanks everyone.

if its 83mm bb I normally do 1 drive side the other 2 are normally spares for smaller BB's!

83mm??!

Blimey! This is getting complicated! How do I know if I have the right BB? My local bike shop is convenient but not graced with social skills and have an air of superiority that means you can ask a question but still doubt the answer!

sorry I meant 68 / 73mm. 73 I use none, 68 one on the drive side. Always measured up to a perfect 50mm chainline. couple of bikes I have had to use 2 on the drive side but that was with a demo which had a dished wheel

I've got an 04 enduro with a 68mm shell. So with a HT2 bb and xt cranks. I have 1 spacer lhs and 2 rhs. Hope this helps?

Perfect Bigyinn – just what I wanted to reassure me.

Ta.