Bicycle Mechanics - '87 Schwinn SS - Cracked drive side dropout. What to do?

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cheeseflavor
03-12-10, 11:21 AM
Just got note from the painter, that after sandblasting my '87 Schwinn Super Sport, he found a crack in the dropout on the drive side of the frame. I'm a large rider and was wondering if you all think this can be fixed by welding:

http://i41.tinypic.com/2rndc37.jpg

TIA,

Steve

dabac
03-12-10, 12:31 PM
This is amazingly like a post from some time ago. And yes, it can be fixed. The elegant way is to replace the dropout. The fast way is to find someone with an electric welder. Arc welding is so fast that it won't upset the braze at the chainstay. If it was me I'd recommend grinding grooves into the crack, to ensure good penetration. But it's possible to hit it with a heavy gauge stick welder and get decent penetration that way.
mmmdonuts
03-12-10, 01:13 PM
My SS died exactly the same way but Schwinn was still alive then and I got a replacement under warranty.

Kimmo
03-12-10, 01:15 PM
The elegant way is to replace the dropout. The fast way is to find someone with an electric welder.

Any reason you wouldn't braze it?
dabac
03-12-10, 02:08 PM
Any reason you wouldn't braze it?

IME it's easier to find a workshop that has an arc welder pretty much up and running, and then convince someone there to run a quick bead around the crack for the price of say a box of donuts. Brazing would run the risk of upsetting the joint at the chain stay, which would require more skill (and time) from someone to get it right. Entirely doable of course, but harder to get it done cheaply.
stedalus
03-12-10, 02:33 PM
Any reason you wouldn't braze it?

I am speaking a little bit out of my element, but for a crack like that I think you'd also have to mash in a piece of copper foil inside the crack. If metal has worn away in any areas, then the silver solder won't fill those gaps. (Cue a brazing expert to come in and correct me.) Also, like dabac said, welding it is much easier.
Kimmo
03-12-10, 02:50 PM
I'd be much happier tackling that with an oxy set, but then I don't have much experience with an arc welder...
jroth
03-12-10, 02:59 PM
How much are you going to spend on an '87 bike? What's the next piece to be replaced?
dabac
03-15-10, 09:51 AM
Nothing wrong with oxy, but arc has it beaten hands down in terms of speed.
Ignoring the time it'd take me to drag the welder out from under the bench I could do a repair like that in less than a minute, if the bike came with the crack ground out.
If I had to reach for the grinder first - maybe three minutes. And that's including clamping the bike to the workbench in some manner.
'Course that also leaves cleaning up the seam afterwards to the owner, but what do you expect for a box of donuts? ;-)