Compact crank & chain length

cal said:

I am about to install a compact crank on a bike which has DA 9spd.
I'm going from 53/39 and 12/27 to 50/34 and keeping the 12/27. How do
I determine how much to shorten the chain?

You can safely remove one link - possibly two... though I'd suggest
wrapping the chain around the 53/27 combo and pulling the ends
together, leaving one more link than necessary to "barely close" the
chain at maximum derailleur tension. You never know if the original
builder got it right...

Mark Hickey
Habanero Cycles
http://www.habcycles.com
Home of the $695 ti frame

Put on the 50x34. Shift to the 34/13 combo. If the rear der cage is
wrapped up too much, remove one link. If it's still wrapped up too much,
remove another.

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