MegaSack DRAW - This year's winner is user - rgwb
We will be in touch
Started building up my ragley trig and I come across the following issue…
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Can’t get the preload nut thing in as I’ve run out of crank spindle, what’s gone wrong?
someone save me from madness…
Yeah three spacers only required for 68mm bottom bracket shell
Looks like I need to brush up on my measuring skills, thanks all
SMBB52 is the wrong BB for GRX, each cup is 10mm wide. GRX uses Shimano road BBs which are 11mm wide.
Can use the SM BB52 if shim it out.
GRX/Road BBs should be 90mm wide for a 68mm shell & no spacers. Shimano MTBs (like SMBB52 with spacers) are 95.5mm wide for a 68 or 73mm shell..
You measured correctly, it is 68mm but as above, the road spacing of GRX and the mountain bike nature of the bb have caused issue.
Quick fix is just one spacer of 2.5mm rather than 1mm each side. That will throw your chainline out slightly which may, or may not be a problem, or even noticeable.
Further to my comment above, the trig is 68mm bb width so something else is fundamentally afoot here beyond using an MTB BB on road cranks. What's the spec of the cranks?
So, removed spacers, just one left on drive side, all fits nicely and spinning freely now
Still need to get wheels (hopefully VERY soon) so I’m assuming that will highlight any issues re chainline etc?!?
unless I’m reading this wrongly….
is the BB I have the completely wrong thing and I’d be better off looking for something else?!?
Should be OK. With one spacer its 0.5mm too wide which is no big deal for Hollowtech2. Just dont overtighten so it puts too much side load on the bearings