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  1. #1
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    IRD inspired brake project and problem

    So I have this bike...

    The rear triangle is very small. (Some of you know what it is.) When I had the original Ritchey cantilever brakes on it, my heels would hit the brake arms. I ended up some time later with these XT low profile brakes, but the brake action is marginal at best. I'm not able to set them up properly. The problem turns out to be the narrow Ritchey rim (21mm) combined with a fairly wide 88-89mm distance between brake posts. There isn't enough brake pad post to get the pads in far enough. The arms are too close together even at maximum width. With the arms this close, the straddle hanger should be lower for more power, but I fear clearance issues, and things might get a bit spongy. You can see the failure of brake geometry here:
    Loose
    IRD inspired brake project and problem-20141021_202208_zps05e38618.jpg
    Tight
    IRD inspired brake project and problem-20141021_202405_zpsea2de9db.jpg

    The brake posts on my other bikes are 81-85mm apart, and most rims are a little wider. It's just this bike that vexes.

    I thought about modifying some brake arms I have. I was inspired by these old IRD Switchback brakes, which cannot easily be found. (Sadly, this is not my bike):
    IRD inspired brake project and problem-6853832196_49007d64dd_z_zpsb07f1946.jpg

    It's because I also had these sitting around:

    Old Avids and some pulleys
    IRD inspired brake project and problem-20141021_202535_zps04fd3bca.jpg IRD inspired brake project and problem-20141021_202631_zps5c537edb.jpg

    In my book, old brake arms, pulleys and a drill press equal a project. It's like 1990 all over again. I thought with some drill and cut, I might mount these pulleys, shorten the arms, and figure out a straddle hanger. Then I'd have my own set of IRD style brakes. Here's a mock-up where the pulley might go. It's right where the spring stop is. If I could pull out the stop and drill through, then a new screw, nut and pulley could live there:

    IRD inspired brake project and problem-20141021_202707_zps3f3a64a6.jpg

    But I thought first that I might try these old Avids on the bike with a standard straddle hanger and see if I could get them to work with my old Ritchey cantilever brake levers. Why not experiment before I cut?

    I ran into the same problem with these Avids as with the XT brakes: too wide brake posts, too narrow rim:
    Loose
    IRD inspired brake project and problem-20141021_204258_zps04a65453.jpg
    Tight
    IRD inspired brake project and problem-20141021_204312_zpsa517ebe2.jpg

    Fail. I see no way to move the pads in far enough to get the brake arms even close to vertical. I'm at maximum pad spacing.

    This was to be a post asking for advice on the pulley location for my new IRD-Steve-o brakes, but it has changed to...

    What brakes work when you need super low profile cantilevers, and you also have a long distance to the rim? Do any fellow retro-grouches have an idea?
    Last edited by whatisaidwas; 1 Week Ago at 11:29 PM.

  2. #2
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    The IRD Switchback brake is really spongy, no matter how you set it up, at least with a non V-brake lever. The set up instructions say to put the pads as close to the rim as possible, even letting them rub, to mitigate the fact that brake levers at the time simply didn't pull enough cable.

    There are a few early V-brake designs that used pads with smooth studs rather than the threaded studs. The Avid Tri-Align III and Paul CrossStop come to mind. These *might* allow the pads to go in farther.

    You might also be able to replace the threaded part of the brake pad holder on a V-brake pad with a longer bolt by modifying the head to fit.

  3. #3
    velocipede technician
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    Ritchey pads
    looking for 20-21" P team

  4. #4
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    Quote Originally Posted by hollister View Post
    Ritchey pads
    That's a good point. The old Ritchey canti pads are a lot thicker than most. The extra pad would allow the arms to be run further out.
    Each bicycle owned exponentially increases the probability that none is working correctly.

  5. #5
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    I found them to be the same as WTB and Eagle Claw II. I'm not sure if this is an improvement over the pads above.

  6. #6
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    Thank you for the ideas.

    Quote Originally Posted by DoubleCentury View Post
    The IRD Switchback brake is really spongy, no matter how you set it up, at least with a non V-brake lever. The set up instructions say to put the pads as close to the rim as possible, even letting them rub, to mitigate the fact that brake levers at the time simply didn't pull enough cable.
    Agreed, but I think back then we didn't set those IRDs up correctly. To work better with a standard lever, the pulley cable loop should be much longer, and the straddle hanger should be much higher. You want the cable to go nearly straight up and down from the hanger to the pulleys. The IRD photo in the OP is not a good setup. But mostly there isn't room to do a higher hanger. My original IRDs were on a Slingshot, and there was very little room between the housing stop and brakes. Sadly I gave up those brakes before I knew how cool they could be. I regret that.

    This bike is a Softride setup, so I've got lots of room front and back to get that hanger up high and try it. If it's still too spongy, I might put on some V-levers. Whatever setup I end up with, I wanted a brake with bare cable down to the brakes, so I don't have to clamp a housing stop and deal with zip ties, etc. It's cleaner if I can get a bare cable brake to work a bit better.

    There are a few early V-brake designs that used pads with smooth studs rather than the threaded studs. The Avid Tri-Align III and Paul CrossStop come to mind. These *might* allow the pads to go in farther.
    Good idea, I looked at those, and it's a possibility.

    You might also be able to replace the threaded part of the brake pad holder on a V-brake pad with a longer bolt by modifying the head to fit.
    Also a good idea. I could see hitting a couple of bolt heads with the Dremel too. I came across a better idea. Remember those Aztec/Delta threaded brake pads? Instead of an Allen nut like the new V-pads, they had an 10mm nut on the threaded pad post. One side of the nut was chamfered , and it does fit OK against one of those concave washers on a V-pad setup.

    Name:  a_aztec_comp_pads_zps8698458e.jpg
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    Those nuts are awkward to get to on a V-brake, so I might take the Dremel to the current V-pad Allen nuts and shape them like that. This way I can remove a part on the outer side and put more spacers on the wheel side to get the pads in there.

    At some point, when the pads are far inboard of the brake pivot, the pads are going to move up and down more, causing tire havoc. I could see playing with some parallelogram V-brakes like the old XT/XTR. Maybe these would be the basis for my pulley brake mod.

  7. #7
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    Quote Originally Posted by hollister View Post
    Ritchey pads
    Good idea too. I know those pads. They are very sleek, and they do work well with the skinny Ritchey rims, which don't have a lot of real estate on the braking surface either. But I don't think they're much thicker than a Shimano or some others.

  8. #8
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    So perhaps this a sacrilegious statement..... but why not just swap out the wheel to another wheel with a wider rim and solve your issue that way? Based on the willingness to use various types of brakes and even modify a set, doesn't seem that this will be a period correct build anyways.

    Just feels like a lot of design work for something that a wider rim would solve.

  9. #9
    Stokeless Asshat
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    I agree but a fun project all the same.
    Quote Originally Posted by datmony View Post
    So perhaps this a sacrilegious statement..... but why not just swap out the wheel to another wheel with a wider rim and solve your issue that way? Based on the willingness to use various types of brakes and even modify a set, doesn't seem that this will be a period correct build anyways.

    Just feels like a lot of design work for something that a wider rim would solve.
    Zip ties? Not on my bike!

    Want:
    650B rims or wheel set. 80's vintage 32 or 36 x 135mm

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