Join Date: Nov 2007
Location: Boston, MA
Bikes: '07 IRO Mark V, '01 Cannondale Jekyll 3000, '07 Rivendell Atlantis
Mentioned: 0 Post(s)
Tagged: 0 Thread(s)
Quoted: 0 Post(s)
Most cantilever brakes will rock somewhat, they ride on a bushing and unless the tolerances are really, really tight you'll definitely notice some play. But this is pretty normal and shouldn't cause any problems. If it's severe it may be that the arm fixing bolts, or pads are loose, I'd check them if there's any question. I'm still running the R550 on the rear and it works fine there --better in some ways-- high profile cantis like the CR720 and Paul Neo-Retro can clip your heels and get in the way of panniers and racks unless you're on a huge frame.
Are you using the supplied straddle cable for the R550? If not the height of the straddle cable hanger and the angle of the straddle cable can have a big effect on braking performance, I'd double check the setup if you're not using the supplied cable. If the set up is OK then getting a set of the CR720s for the front may help you out if you're not getting good stopping power.
2009 Bike Friday Season Tikit (commuting folder)
2007 Rivendell Atlantis (touring, general riding, errand runner, stuff hauler)
2007 IRO Mark V (SS)
2006 Rockhopper Comp Disc (Icebike)