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H!
I am currently rebuidling my bike after its annual strip down and service ready for the bike season (still a little snow on the ground here)
Anyhow, i've never been really happy with my GX eagle shifting.
Banshee Titan
73mm threaded BB with splined ISCG-05 i 'plate' with a oneup bash
XTR FC M9020- B cranks
XT BB.
i have from left to right crank arm BB shell, spacer on the non drive side,frame, spline plate BB shell, weird spacer thing, crankset.
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The weird spacer thing is there otherwise i get around 2mm of play wen everything else in in place.
It all seems to much and is perhaps detrimental to shifting an chainwear. ...or?
spacer on right too between spline plate and bb shell
Bump for the evening cru. Hope this is still a bike forum 😬
pretty sure the hollowtech 2 manual has the diagram for all the possible spacer arrangements in it
i think....
on my xt bb, i have a spacer on drive side only under BB shell, but can't easily see atm. there may also be multiple thickness spacers with BB's.. just look up the bb manual and work back
I agree with howsyourdad - throw your "weird spacer thing" in the bin and install another 2.5mm spacer on the RHS between the spline plate and the BB shell...
If you need to use a bottom bracket mounted chain guide or derailleur, then you'll also need to remove the innermost 2.5mm spacer on the drive side - so a 68mm or 83mm shell will have one drive side spacer and one non-drive side spacer, while a 73mm shell will need no spacers at all.
https://off.road.cc/how-many-spacers-install-bottom-bracket-68-73-shimano-hollowtech-sram-gxp
so apparently i need no spacers anywere? not even for boost spacing?
Boost is a hub ‘feature’ so the bottom bracket has no bearing on it.
Some chai sets do have different spacing to accommodate the chain line changes caused by boost rear winds but that’s almost always in the ring itself if not the crank arm so the bb spacing shouldn’t need to be worried about. Basically the total width of the frame’s bb shell and spacers used is a set distance so if you add a spacer or similar on one side you need to take the same amount out of the other side.
ok thanks. it just feels like i am using alot of spacers! one on nds, 2 on ds, and the bashplate!
i'm talking to myself but my XTR cranks are for 55mm chainline. thats why three spacers are needed. doh
Yes you are correct. I bought some slx cranks for 55mm chainline and there are loads of spacers. You can have spacers on nds or ds depending on frame configuration. I think I have one extra on nds to move chainline in so it’s more like 52 than 55 and it shifts fine. Can’t check right now as not at home.
There are different numbers for the cranks to denote this.
Edit: 7100 is 52mm, 7120 is 55mm. Presume similar for xtr