1422

I have a Shimano 3 ring crankset with bent chain rings. I never use the smallest ring (granny gear). I'm thinking about replacing it with a 2 ring crankset. The current bottom bracket is 68x122.5. The crankset I'm looking at recommends a 68x110. The question is, would reducing the bottom bracket size cause any alignment issues? I would think there would be enough play / space not to cause any trouble but I'm not 100% sure.

If this won't work, I may just replace the crankset with another 3 ring and just not use the lowest gears. I live in very flat land and will never really use them.

Thanks - any and all responses much appreciated.

bboy314

It really depends on which crankset you use. Bottom bracket length depends on the particular crank, not just whether it’s a double or triple. In this case the chainline will be off, and your front derailleur may not reach far enough to shift to your large ring.

Is replacing your chainrings an option, or are they the riveted type?

13ollocks

You match spindle length to crankset. Assuming your bottom bracket shell is pretty standard, if the double crank recommends a 110mm spindle, then get that one.

1422

Understood. Unfortunately riveted. This definitely limits my replacement options.

bboy314

When replacing a crankset, it’s usually necessary to install the correct bottom bracket as well, so just get the BB you need.