I spent a good part of yesterday scratching my head over a Hope crankset / Alpine 160 / MRP AMG chainguide combination and wondered if anyone has any suggestions…

My frame has ISCG (old) tabs and with a 24mm axle crankset all is well with the world. Unfortunately it’s crank upgrade time and I went out and bought a pair of shiny Hope cranks without giving things much thought. These come with a 30mm axle and so require a BSA30 bottom bracket, which fits the frame fine. No problems so far.

The problem comes with fitting my chainguide. I have ISCG (old) tabs and so my MRP AMG (v1) guide has a cutout within the ISCG bolt circle that fits over a standard BSA (24mm axle) bottom bracket cup. With the new BSA30 BB, the driveside cup pinches the guide’s backplate when spaced correctly (one 2.5mm spacer between the driveside cup and 73mm BB shell). If I install the thinnest washers (0.8mm I think) I have between the ISCG tabs and guide backplate, then there is just enough clearance to tighten the BB cup all the way in to the BB shell, but that leaves the chainguide way out of line from the chain, so that’s a no-go either.

So it seems my options are: move back to 24mm cranks; run without a chainguide; buy a new frame with ISCG 05 tabs(!); find a different chainguide that fits. Given I’ve come this far, if anyone has any suggestions on the ‘different chainguide’ option I’d be really interested to hear them. After a lot of Googling I’ve found it pretty difficult to find any information at all about this kind of combination, although I would have thought at least someone out there running RaceFace Cinch, Rotor or Hope cranks might have hit this issue. A guide that fits around the BB (replacing the 2.5mm spacer) would probably work just fine, although it seems a shame not to use the stronger ISCG mount option. A guide with a thinner backplate, or one which allows for adjustment for the chainline at the guide point, rather than spacing out the backplate from the ISCG tabs, might also work – but I have no idea if such a thing exists.

Any advice very much appreciated!