Hi everybody, just a little background.. I am working on rebuilding and updating a mid 1980's Gitane Grantour. I am almost completely done with the project, it has a pretty decent looking rattlecan paintjob (will have to post pictures later after I put on the new decals). I have installed a new Dura-Ace bottom bracket and crankset along with new Sora STI levers, a Dura-Ace front derailleur and a Diore XT rear derailleur. everything is working perfectly so far but I have run into a problem with the new cantilever brakes I am trying to use. They are Shimano BR-550 cantilevers ( http://harriscyclery.net/itemdetails.cfm?ID=1277 ). The problem is that they rotate to the point that they contact the rim before the springs engage to provide any resistance. The brazed on bosses only have on hole in them for the spring. I am looking for suggestions for how to correct this so I can get the bike back on the road. I am considering drilling a new spring hole at the top of the boss to see what that does, I am also considering going to a different set of brakes like the Tektro CR-720's to see if that helps as they at least resemble the original brakes (Mafac wide profile cantilevers) and may work better. Anyways sorry to ramble on here but any help would be appreciated.
You can rotate the arms out (while mounted on the posts) and stretch the spring so it gives you more tension. Or take out the springs and bend them a little bit. Its what you have to do with spookys old mafacs, other similar brakes so I don't see why you cant do it with the brakes you have.
Thanks for all of the replies. I got this worked out with some help from Sheldon.. He suggested that I move the spring peg up one hole on my bosses, I only had one hole to use.. up until today now there is a hole up high enough to get the springs to engage and everything is working perfectly, now I just need to order some of the thin profile pads for the front so I can get a better alignment on them as it is pretty tight now (but functional).