[smedford]

I have a steel HT that I love to ride, but I wish it had a disc adaper for the back. I work with some guys that can weld and it looks like it would be pretty easy to mount up an adapter to put some avid mechs on.

Avids are very adjustable, so it would not even have to be perfect.

Any thoughts?

 

[gtbike]

On the rear I would go for it. On a fork though I would think twice. I saw a guy who made a bracket that went from the rear skewer to the rear brake post that held a caliper. He was racing with it and said it worked okay. Pretty cool and bolt on!

 

[Repack]

From what I have heard, welding to steal is easy. Using an Avid would mean being able to compensate for any alignment issues with thee CPS. Go for it.

 

[Matt D]

I've seen it done quite a few times to steel frames, you should be fine. But all of them were done at places that specialize in bike stuff, not just your local welder. Getting the tab alligned properly is pretty big IMO, even if you can shim the caliper enough to get it to work, if it's on a crazy angle or something it will create some strange forces.

I'd be careful.

Oh yeah, I know a guy who builds frames; somewhat ghetto-ish. He basically puts a disc hub with rotor attached into the drop outs, puts the caliper with disc tab attached on the rotor to line it up, and welds away. Works for him, it might for you.

 

[bomberz1qr20]

If you're worried about the frame integrity being affected (you didn't state what kind of tubing this was) ask one of your welding buddys if they can braze the disc tab on.

Brazing has 90ksi holding strength or better (often a stronger bond than the metal being joined) and it is done at a lower temp than welding.

The joint can be a "T" or a lap joint. Fit up and alignment are key.

Good luck.

 

[Lexx D]

It is only a problem if you plan on doing trials. I tapped an old cannondale frame and put disks on it(the trek disc attachment fit oh so perfect). It held up until my 275 lb friend started pedal kicking around the shop then....snap and on his ass he went..hahaha
But I do think it will be fine.

 

[Repack]

Originally posted by Lexx D
It is only a problem if you plan on doing trials. I tapped an old cannondale frame and put disks on it(the trek disc attachment fit oh so perfect). It held up until my 275 lb friend started pedal kicking around the shop then....snap and on his ass he went..hahaha
But I do think it will be fine.

Thats is a really good idea. I have heard that rear discs and trials don't mix well in general, but I could be wrong. A friend of mine who competed said that when hopping on the back wheel, the forces are trying to rip the caliper away from the frame, instead of the braking forces being directed into it. He said that discs make it too easy to crack a stay b/c of that.
Anyone know if Mountain Speed (or anyone else) still makes the disc tab clamps? I think they may have only been for old FSR's.

 

[Lexx D]

Two broken treks a bruiser and a 8500, one cannondale and an ellsworth specialist all dead from pedal kicking...(and i didn't mean the one we tapped, I don't balme cannondale)

 

[skinny]

Originally posted by gtbike
I saw a guy who made a bracket that went from the rear skewer to the rear brake post that held a caliper. He was racing with it and said it worked okay. Pretty cool and bolt on!

I think Brake Therapy Components (if they're still in business, haven't heard from them in awhile) makes a disc brake adatper that attaches to the V-brake post. Stay the hell away. V-brakes posts are designed to take the outward forces imposed by V-brakes, not the upward forces imposed by discs.

 

[mcA896]

suggestion: find an old cheap broken down frame thats disc compatible and chop of the dropout wit the disc mounts and weld it on in place of ur current one

 

[Matt D]

Originally posted by mcA896
suggestion: find an old cheap broken down frame thats disc compatible and chop of the dropout wit the disc mounts and weld it on in place of ur current one

Are you kidding?

Hopefully you are; would you rather your disc or your wheel snap off? The possiblity of sharp metal tubing to crash on doesn't excite me much.