My buddy D. who owns Nashville Bicycle Lounge, just updated the
running gear on his cross-check. Can't remember which cranks, but it's
a double up front, Suntour Accushift downtube levers, 7spd corncob
rear on a 600 hub, XT medium cage rear mech, and a Campy record front
derailleur. Works perfectly. Friction--if it doesn't work perfectly, a
flat file will fix it.