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Wednesday, August 10, 2016

Modern Cantilever Brakes on a Vintage Touring Frame: A Cautionary Tale


In general, older brakes don't have quite the same stopping power and responsiveness of newer versions. The return springs tend become less sharp in pulling calipers or cantilevers back to their resting positions and the parts just don't seem to engage with one another quite like a brand new set of brakes. Plus, my Panasonic Touring Deluxe uses cantilever touring brakes, and finding original-era parts can be difficult and expensive (used versions of the Shimano AT-50 cantilevers that originally came on the bike can easily fetch $50-100 for a full set on eBay - comparable to many brand new cantilever brake sets).

Luckily, the resurgence of touring bicycles and the creation of multi-use styles such as cyclocross, hybrid, and gravel bikes have brought cantilevers and V-brakes back onto the market in a big way. So after reading numerous reviews, taking careful consideration of my limited budget, and accounting for the look and aesthetics that I'm targeting with the finished machine, I decided to go with Tektro CR720 cantilever brakes on the Panasonic touring bike. The CR720s have a fantastic, vintage-touring look and feel, are fairly well regarded by other touring cyclists, and are somewhat inexpensive. I found a great price for the brakes online and bought them.

Soon after receiving my Tektro CR720s, though, I discovered a problem. When I slid the brake arm and return spring over the post, I immediately noticed that the arm was extended so far outward that it was slumping downward. And the brake pad hit the braking surface of the rim at an angle, so no matter how much I fiddled with it in the slot of the brake arm, it was always contacting the rim along the edge of the pad where it would do almost nothing to slow or stop the bike. There just wasn't enough room for the brake to contact the rim appropriately. The rim and cantilever post were too close to each other.

I read through bicycling forums and quickly found that others had run into the same problem. Cantilever post spacing on older bikes is much more narrow than on modern frames and often won't accept newer canti brakes. So I was left with two choices: bite the bullet and pick up a set of vintage cantilever brakes at a premium price or keep buying different models of cantilever brakes until I found a set that worked through trial-and-error.

That's when I remembered that I had stashed away an extra pair of old Shimano Altus CT91 brakes that I had mounted onto my GT Outpost mountain bike. I dug out one of the brake arms and slid it over one of the Panasonic's front cantilever posts. After a bit of tinkering with the position and angle of the brake shoe, Voila! It fit perfectly! Even better, the CT91s are still widely available and can be purchased new very inexpensively (it's not uncommon to find them on sale for under $10 a pair). Admittedly, they don't have the same vintage look of the Tektros - in fact, I'd go so far as to call them ugly as hell. On the other hand, they've got fairly long brake arms that are pulled tangentially to the arm's direction of travel, giving them a decent braking force compared to the more widely-set touring and cyclocross brake arms of other models. And speaking from years of experience using them on my GT Outpost, they're pretty much indestructible.

They may not be pretty, but the Shimano CT91 brakes should work out well. In fact, they may be the only modern cantilever brakes that will work on my vintage touring frame.


2 comments:

  1. I've got a few bikes that use cantis, and have noticed that the Tektro 720s are definitely more "fiddly" to get right, and they don't play well with all rims, though they really are nice once everything is dialed in.
    I had an old Fuji that was frustrating me w/ the brakes. Came originally with Dia Compe cantis, but they had stress cracks and needed replaced. Bought the 720s, and couldn't get them to work with the wheels that were on it* so I tried the Tektro Oryx, and they fit up nice and easy. Work great, too. The Oryx brakes are inexpensive, and they don't look out of place on a classic old bike, BTW.


    *I eventually built up some new wheels for that bike with Sun CR18 rims, then the 720s worked fine. Weird.

    Wolf.

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    1. Thanks for the tip on the Oryx brakes, Wolf! I've already ordered a set of Altus brakes (which works out well, since the rest of the build will use Shimano components), but I may end up testing out the Tektros if the Shimanos' braking performance is insufficient.

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