Bicycle Mechanics - replacing "that thingy" on my brake that allows me to adjust my spring.

I know, I'm awesome at describing things in my title.

Anyway, I have some old deore xt canti brakes on my bike that I really like, but getting the centering adjustment when they're on the bike can be a real pain in the ass because of the racks I have on (especially the front rack). In theory, it shouldn't be a big deal to change which hole the spring is in as I should be able to back the brake off a bit while keeping it on the peg so that the spring goes out of the hole and then use the little tab associated with the "backplate" that keeps the spring in the brake and has the end of the spring coming out of a little hole to move the end of the spring to a different hole on the brake mount.

Unfortunately this "backplate" (anyone know what the real name for this is if I'm making any sense at all?) is made of plastic and has broken (or at least the hole the spring end comes out of has expanded to the point of uselessness) in 3 of the four brakes.

Does anyone know if I can get replacements for these parts, and, if so, where? And if I can get replacements for them, is there any way to make them metal so they don't break so easily?

I do have a set of the BR-550 canti brakes kicking around somewhere that I could put on instead, but I don't think they have a low enough profile to allow me to mount my panniers on my front rack (not a frequent occurrence, but helpful on a big grocery run).

Thanks so much for any and all help.

when the plastic spring retainer breaks on those shimano brakes we just replace the brake with the altus unit i think 13 for a set.

himespau: If 3 of your 4 brakes are busted I'd dump them. For my money you can't go wrong with the Tektro CR-720s, if they will clear your racks (or if you can work the racks around them.) Simple, easy to adjust the pads and no plastic parts.

ah spring retainer, good to know. Currently, I have the brakes set up and they're working just fine, but I know the next time I have to take them off for some reason, resetting them will be a pain. Might replace at that time. Will probably look at the shimano 550's I currently have before trying something new, but thanks for the input. I've heard a lot of people like those CR 720s, so I'll give those a look if the shimano's don't work with the rack setup.

Those plastic spring bodies were a POS. Some of the higher end Shimano cantis from that era had a metal housing. I would look for a deal on a used replacement.