Afternoon folks

I’ve just whipped my cranks off to service the BB. The BB is now fine however I just can’t seem to ‘nip up’ the cranks on the BB itself and have some lateral play on them at the BB. They’re just not tight enough on the BB but I’m not sure how to tighten them – is it just a soft hammer job or does the crank extractor tool have another function?

Thanks!
TS

Missing chainline spacers?

I could definitely be dozy enough to miss that so will check, cheers.

TS

There should be some spacers on the axle to take up the play.

IIRC theres a 2.5mm rubber/PU/whatever spacer in one (or both?) of the cranks then you add 1mm plastic spacers untill the space is filled and the deformation of the 2.5mm washer is what pre-loads the bearings.

There’s a mix or ‘rubber’ preload washer (at 2.5mm thick) and chainline washers (1mm thick rubber coated metal washers).

Off the top of my head I can’t remember how many you need on a 73mm BB. I think it might be 1 preload and 3 chainline in total.

On a 73mm BB you’d need one off the BB spacers. But the 1mm washers are to account for variations in the 73mm, so the number required will vary frame by frame. The easiest way it to assemble it without them and guess how big the gap is by eye. I think my last frame needed 4.

I had a pair that eventually wore out and wouldn’t stay tight. Checked it by mix and matching with another set I had, and the older pair were definitely shot. However the play felt more ‘fore/aft’, like slippage under power.

But the 1mm washers are to account for variations in the 73mm,

That’s not what Race Face fitting instructions say they’re for. It say’s they’re for setting the chainline (69,70 or 71mm ?).

The spacers are all in place. The BB is tight, the cranks are moving laterally within the BB if that makes sense? I’ve got a feeling the drive side needs to be ‘pushed’ further in, just not wanting to use force where I shouldn’t be!

TS

Have you put all the spacers in the Bottom Bracket?

The little rubber ones that sit between the BB face and the crank face are prone to perishing too, sorry but very bad system. If mine were anything to go by, the wobble is the beginning of the end too as the splines are probably already a bit chewed up.

That’s not what Race Face fitting instructions say they’re for. It say’s they’re for setting the chainline (69,70 or 71mm ?).

Depends how mnay you need?

http://www.bike-components.de/bedienungsanleitungen/2011/raceface/cranks/atlas_am_crank.pdf

Those instructions just show 1 on each side but I was told to add/remove as nececary untill all the space was taken up.

[edit] read the troubleshooting section. It should be 1 each side if the BB is perfect, mine was obviously on the piss as it needed about 4!

I never looked into chainline, can’t see how 1mm makes any differance with 15mm of movement accross 3 rings and ~50mm of freehub! Mine was on SS anyway so used the freehub spacers to get it right.

Well according to the link it’s 2 washers positioned to give you the chainline you need. Freely admit my memory wasn’t up to much on this occasion numbers wise.

In the past I have added extra to make up for an overly faced BB shell.

Should be noted that for 83mm shells more 1mm washers are used. My Shocker has 5.