andrew- Since the biggest and smallest cogs aren't any farther apart on a
ten-speed cassette, what is the obstacle to using a nine-speed rear
derailleur with a ten-speed shifter, cassette, and chain? Is it the
pulleys? BRBR

No obstacle, just use it whether it be shimano or Campagnolo. no need to change
anything. The shifter makes sure the chain moves the correct amount these days.

Peter Chisholm
Vecchio's Bicicletteria
1833 Pearl St.
Boulder, CO, 80302
(303)440-3535
http://www.vecchios.com
"Ruote convenzionali costruite eccezionalmente bene"