Bicycle Mechanics - cold setting steel & brake bridge

I have an old Trek touring frame that I would like to get back on the road with a selection of modern components. Since I am already going to powdercoat the frame since the original paint is in poor condition, I am considering having a local framebuilder that I know add downtube shifter braze-ons so I can use downtube shifters -- the frame came with only a clamp on. I'd also like the rear spacing to be set from 126mm to 130 or 135mm to accommodate a modern hub/drivetrain. While I am having frame work done, would it be smart to have the rear brake bridge removed and have a longer one installed to be on the safe side? Or is it fine to simply coldset as is?

Thanks.

Coldset it as is....the bridge will be OK. 130 is the back will OK.

if you're going from 126 to 130, I wouldn't even bother to cold-set, I've done the exact same thing (actually, a trek touring bike as well). All I do is stretch out the frame those 4mm when I place in the wheel. It's not hard at all, and I've never had a bit of trouble with it.

Is there something wrong with clamp on downtube shifters? It seems like a lot of work for very little reward getting the braze-ons.

yes you could simply spring the frame open every time you mount the rear wheel, but why bother. Spread the frame, and re-square the dropouts and don't worry about the brake bridge. It's a very small change in angle and will spread from the bridge down perfectly well.

if you're going from 126 to 130, I wouldn't even bother to cold-set, I've done the exact same thing (actually, a trek touring bike as well). All I do is stretch out the frame those 4mm when I place in the wheel. It's not hard at all, and I've never had a bit of trouble with it.

I've had the same experience with my Schwinn Voyageur. It takes a little effort to get the hub in there, but not much.


Is there something wrong with clamp on downtube shifters? It seems like a lot of work for very little reward getting the braze-ons.

I agree. How much is that going to cost?

yes you could simply spring the frame open every time you mount the rear wheel, but why bother. Spread the frame, and re-square the dropouts and don't worry about the brake bridge. It's a very small change in angle and will spread from the bridge down perfectly well.

How do you "re-square" the dropouts? Is this really necessary for a 2mm per side change?

How do you "re-square" the dropouts? Is this really necessary for a 2mm per side change?

There are tools made specifically for the job, similar to this set (http://velobase.com/ViewSingleTool.aspx?ID=32FC06A7-76A1-41E7-9146-A98AE849D2A0&AbsPos=17) and any decent shop would have a pair. It probably isn't enough angle change to worry about if you know the dropouts were right beforehand, but I'm of the old measure twice cut once school, and as long as I were doing the work, I'd check them before painting.

You can protect the Brazing joint of the brake bridge by making a jig to restrict it from spreading there,

so as to keep the bending below that point. I've seen the brazing pop off on one side in some situations, ..

The bad thing about putting a wider spaced rear hub into a frame is the bending load put on the axle. It can wear out the hub bearings over time.

I agree. How much is that going to cost?

$25

clamp-on shifters suck, that's why.

thanks everyone -- I'll go ahead and coldset away. just so this is clear, it is safe to go from 126mm to 135mm? I'd rather use a 135mm hub.