My chainring is rubbing on the right, rear chainstay when I attempted to install my crankset.
- Frame: Trek 520 Disc (54 cm)
- Crankset: Shimano 105 FC-R7000 (52/36, 170mm)
- Bottom Bracket: Shimano Ultegra BBr60 (68mm English)
I have built up a few bikes now but hadn't yet encountered this issue. I was thinking a touring frame would accommodate road cranks, but I guess I was wrong. Trek doesn't provide really any documentation on this frame besides the geometry measurements given on the link above.
- Spacers between BB and frame. Based on other forums and Shimano's "Dealer's Manual," this does not seem safe or even plausible. If I add spacers, the spindle will be too short and the inner cover will not sit snugly as it's designed to.
- Buy smaller chainrings. I may upload a picture if needed, because the rubbing is on both the large (52t) and small (36t) chainrings. I wouldn't even know what size to buy or how to measure to ensure it wouldn't rub.
- Replace crankset and bottom bracket with long spindle and smaller crankset (Octalink, square taper whatever). I'd prefer not to do this, because for some reason I decided to throw the packaging away and now I can't return it.
- What kind of compatibility between cranks, BB, and frames do I need to be aware of to prevent this?
- What might be the most efficient/cheapest workaround?
- Is there something fundamental I am missing that should come with a bottom bracket?