Originally Posted by
Cassopher
Sounds expensive and yes I’d have to replace the quarq PM also. Could I put a 12/28 or 12/30 cassette to ease the ratios a bit? I currently have an 11/28 with that 53/39.
A 12-28 shouldn't require any change.
A 12-30 means you'd need (on paper) another 1/2" of chain for the 2 additional teeth of the largest cog.
Do the test in the pic below- Chain on largest ring & cog.
IF you have at least 3 half links slack, you won't need a longer chain for a 30T cog.
Without knowing what RDER you have, one doesn't know how much chain wrap capacity OR the largest cog it could handle. You "might" be ok with a 30T?
You "might" have a bit of chain sag in small:small.