# Welding disc mounts on older frame?



## Hoban (Oct 14, 2012)

My buddy has an older Gary Fisher Sugar that we would like to tig some disc post mounts onto it to update the brakes. Trek would do it for $500. :skep:

Anyone do this? Where would we source the parts? Thanks!


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## SenorSerioso (Apr 22, 2011)

Whoa! I'd rather just get some nice cantilever brakes instead, that's brutal.

Wouldn't any hand builder be able to do this? Come to think of it, sanding measuring, welding, priming, painting and then the brakes/wheels to go along with it once the work is done it sounds like it'll be an expensive process anyway even if you found an alternative to Trek.


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## Hoban (Oct 14, 2012)

Nice and cantilever brakes are sort of antonyms in my dictionary... 

It gets wet here. Plus you can't beat hydraulics IMO.


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## SenorSerioso (Apr 22, 2011)

I don't disagree with you


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## Hoban (Oct 14, 2012)

It looks like there may be some factory bolt on mounts for it. Be nice to sv e the paint back there. Just need to find the exact year...


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## shiggy (Dec 19, 1998)

Hoban said:


> It looks like there may be some factory bolt on mounts for it. Be nice to sv e the paint back there. Just need to find the exact year...


This is what you need
http://www.ebay.com/itm/Rear-disc-b...Cycling_Parts_Accessories&hash=item2c6d1d430d


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## Berkley (May 21, 2007)

Unless you can heat treat it when you're finished, it's a bad idea.

Read: To the Point: Heat Treating Aluminum Frames - Pinkbike


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## Hoban (Oct 14, 2012)

Thanks Shiggy. I'll have him take a look at his drop out, see if it'll be compatible. 



Berkley, thanks for that. I do know it won't be too hard for us to heat treat back to T6.


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## Walt (Jan 23, 2004)

So I assume you know the bike isn't worth this amount of attention and just want to do this for fun. Taking that as a given:
-Make the PMs yourself. That's dead easy. If you can heat treat aluminum, you darn well better to be able to drill and tap a couple of pieces of rod. 
-Use an Avid mech caliper as your disc tab fixture (ie install on another bike, clamp down the brake pads to hold it all together, remove caliper/wheel from bike and then install on your Sugar to use as a jig). Or make a jig.
-Weld her on.
-Heat treat.
-Go ride.

Personally, I would spend my energy making something else and just ride the bike as is.

-Walt


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## racebum (Mar 13, 2013)

the welder you use has a big impact on this. i've welded aluminum frames before and always used a miller syncrowave. lincoln and hobart make similar units but you really want to have some skill in being able to weld thin aluminum. 100% argon and quality rod along with a steady hand should make it fairly easy to do. i would not try to mig an aluminum frame ever. 

also note i have never heat treated a welded area or had a crack after. one was even on a pk ripper back when i was 15 and rode bmx. the re weld of the head tube was actually stronger than the OE weld. at least it seemed like it was. i cracked the OE weld but never did the re weld 

not saying heat treating is a bad idea by any means but the rear disc bracket location is in a non stressed area of the frame.


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