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Old 05-25-08, 11:11 AM   #1
BikeMechDS
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622/630 compatibility problem with canti brakes

I bought an old, but really nice, Nishiki Cresta GT touring frame off of ebay. Frame has all the normal fittings of a full blown touring set, including cantilever brake bosses.

The problem is that I have tried three cantilever brakes on this thing to try and get the pads to line up well on the rim. Brand new Avid Shorty 4's are much to long and the pads end up very high up and can only intersect the tire. I also tried a crummy pair of shimano alivio's that I found, they didn't work either. Then I tried a set of cantis off of my friends NOS Lotus Odessy. The didn't have a model name, but they allowed for more pivot in the pads and I was able to get the pads to line up on the rim by pulling the canti arm outward and pivoting the pad at a more extreme angle to aim at the rim. However, the springs were far too limited in their adjustment and couldn't keep the pads away from the rim.

I currently have a Mavic open pro rim on the rear, and the vertical distance from the center of the rear bosses to the mid-point on the rim's braking surface is only about 17mm. The bosses of course are below the rim, not above.

So I'm wondering if anyone has any good suggestions on how to overcome this problem. Does anyone know of a brake-set where the pads can be adjusted very close to the boss bolt and still have correct spring tension? I do have the option of re-brazing the bosses. I know an extremely competent person for this job, however, I would prefer not to mess with the frame in that way.

another possibility is to create a makeshift Drop-bolt setup and follow Sheldon's example. However I can only really see that being effective for the rear and much more difficult to come up with an affective fabrication for the front.

So there it is! Havachu! no idea if that is how I should spell that but you get my drift.
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Old 05-25-08, 10:27 PM   #2
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uo
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Old 05-26-08, 05:21 AM   #3
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Just put 27" wheels back on the bike. That's what it was designed to work with, and there are still some decent rims and tires available in that size to choose from.
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Old 05-26-08, 07:39 AM   #4
jgedwa
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Many have been down this path. Many have been frustrated. I went through it with an old Trek 620 and hit every snag you described.

Don't give up just yet. Look for old canti sets that allow you to adjust both the angle and also slide the post up and down. Sometimes a little judicious filing with a round file will buy you a tad more space. I could not get Shorty's to work either, but eventually settled on a a set of first generation Deore cantis that work fairly well. Because of the extreme angle that you described, smooth post sets (instead of modern threaded posts with cupped washers) were necessary.

One oldtimer suggested filing the dropouts a tad to move the wheel up a mm or so. I did not have the heart to do this, but it could be a partial solution.

Good luck.

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Old 05-26-08, 10:27 AM   #5
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Tektro Oryx cantilevers have a lot of adjustment height for their pads. Paul Components' Moto BMX linear brake also has a lot of adjustability; you might need a travel agent for conventional road levers or use the DiaCompe 287 road levers.
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Old 05-26-08, 10:31 AM   #6
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Originally Posted by CHenry View Post
you might need a travel agent for conventional road levers or use the DiaCompe 287 road levers.
These are cantilevers. They will work fine with any standard road lever. You only need the travel agents or the 287v's when you're using v-brakes.
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Old 05-26-08, 10:49 AM   #7
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Originally Posted by ginsoakedboy View Post
These are cantilevers. They will work fine with any standard road lever. You only need the travel agents or the 287v's when you're using v-brakes.
The Paul's are linear, which use the same posts as cantilevers. They are designed for riders who swap wheel sizes. Going up a size--not the case here if the OP goes from 27 in to 700c--keeping the road levers is OK; going down, the company recommends a long-pull lever, like the 287v.

I was suggesting these as an adjustable alternative to the cantilevers he now has on the bike, one that could work for 27 in or 700c.
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