Disc brake tabs on a Vintage frame.
10-17-15, 05:09 AM
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Disc brake tabs on a Vintage frame.
Is it possible?
Will the Tig welding process weaken the frame tubing?
Will it ever "be right" or is it more likely that the brakes will never line up proper?
Has anyone here done it?
Will the Tig welding process weaken the frame tubing?
Will it ever "be right" or is it more likely that the brakes will never line up proper?
Has anyone here done it?
10-17-15, 06:03 AM
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It can and has been done many times before. Steel frame, no problem. Aluminum, probably not worth the effort. What type of frame? Road or MTB? Disc hub spacing is usually 135mm for both now, although you may still be able to source a 130mm disc hub. The main concern is will the disc fit without hitting the chainstay or seatstay? The best way to determine that is to put a disc wheel in the frame and see if the disc clears the stays.
Aside from aesthetic reasons, there is not really a need for disc brakes on the rear. You could change the fork for disc in the front and continue to use rim brakes in the rear.
Aside from aesthetic reasons, there is not really a need for disc brakes on the rear. You could change the fork for disc in the front and continue to use rim brakes in the rear.
10-17-15, 07:25 AM
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The other issue with using disk brakes on a bike never intended to have them, besides the dimensional fit, is that the tubes and drop outs are not likely as robust as one would want or use for a new frame build. While in the rear it's relatively easy to cross brace the stays to reinforce them the fork is trickier and more the concern as well. One can fab up a caliper tab which extends far up the blade to reinforce it. But this is more challenging a fab job then simply using an off the shelf tab. You really want to transfer the brake reaction forces to the fat section of the blade or risk unraking that blade on a hard stop. After that is figured out you still have the issue of the axle trying to eject it's self from the drop out slot under braking forces. A new fork build would best have the slots facing forward (as in placing the drop outs upside down) so the axle tends to butt against the drop out slot's sides. Of courst a new build would also use a far more robust/stiffer blade (and therefore loose much of the forgiving nature of a classic steel fork). Andy.
10-17-15, 07:58 PM
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Thanks,
I'm leaning towards NOT doing it, it's an old road frame & I was hoping to use new off the shelf hubs. Having to locate the proper 130 ones makes it more hassle than it'd be worth.
I'm leaning towards NOT doing it, it's an old road frame & I was hoping to use new off the shelf hubs. Having to locate the proper 130 ones makes it more hassle than it'd be worth.
10-17-15, 08:46 PM
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Well the spreading of the rear triangle to 135 really is the least of the issues. But probably a best choice to move on from this dream for the other reasons. Andy
