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I'm considering replacing a Shimano Alfine 8 hub with a Shimano Alfine 11.
The bike has a Gates CDX belt drive, and I want to retain the same belt, chainring and rear sprocket.
My understanding is that the Gates belt drive is very sensitive to correct chainline.
Assuming the chainline is currently correct on my bike with Alfine 8 hub, can I substitute an Alfine 11 without having to adjust the chainline?
Thanks
The obvious place to look is Shimano's specifications page, but that does not appear to give chainline.
A bit of googling found a couple of pages that give specs for the Alfine 8 and 11.
This page simply states the Alfine 11 chainline is 42.7mm.
This page gives a more complete picture for Alfine 8, giving chainline for 2 sprocket mounting positions and several models. Seems that 42.7mm chainline is achievable on SG-C6000 and 6010 models.
Presumably Shimano expect you to pair the Alfine hub with the Alfine cranks. The Alfine cranks (FC-S501) have a chainline listed directly on Shimano's site of
49.2 (double chain guard) 42.7 (single chain guard)
It is interesting that Shimano change the chainline if you add the double (inboard) chain guard. You can see the do this with a 6.5 mm spacer.
But they makes no reference to this front crank spacing variability in the manual for the rear hub. This makes me think that the actual chainline is somewhere between 42.7 and 49.2 mm.
