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JimboMartin 01-30-14 09:14 AM

Cold setting 120 dropout spacing to 130. Any concerns about buckling?
Hello All:
I have my eye on a vintage Paramount with 5sp spacing. My vision is to build it with modern components including 130mm spaced hubs. Should I be concerned that cold setting the spacing from 120 to 130mm might buckle the stays? In the past I have used 130 spaced hubs in 126mm frames by simply flexing it open each time I put the wheel on. Somehow I imagine this will not be as feasible with a 120 frame. Any advice appreciated.
Thanks in advance,

Fred Smedley 01-30-14 10:10 AM

Stay material? Hardened steel hard to move , non hardened, easier. Stay length, the longer the easier. I moved a Raleigh Gran Sport out to 130 from 120 and it was really easy, but it has non hardened long stays. Moving stays is always a risk , how good is the braze job where the stays attach?

busdriver1959 01-30-14 12:02 PM

It won't hurt to stick a padded clamp on at the rear brake bridge. Just in case. I can't imagine that 5mm each side would cause buckling. Look at how much fork blades are bent although they are usually bent over a form that gives some support to the sides. I've done a few curved seatstays using the fork blade form with no problems.

Live Wire 01-30-14 12:20 PM

Based on the Paramounts I've worked on of that vintage, the respacing would be easy to do. The quality of the frame construction however, is a total crapshoot with those bikes....they are "paramount" in name only.
I'd closely inspect everything before putting any miles on it.

unterhausen 01-30-14 01:18 PM

I have done that, and worried about it before I did it, but you can't even tell it happened. A heat-treated stay would probably buckle

MassiveD 01-30-14 09:14 PM

Cold setting isn't a problem, pretty much every build involves cold setting. However, from a framebuilding perspective just randomly torturing the rear end for some unspecified reason isn't what I stand for. If you asked frame builders whether they just randomly designed that way, or randomly set the rear end accuracy that way you would get a hefty argument about what techniques are best and what accuracy standards are reasonable. Of course I am all for helping people and their politely asked questions, but I wouldn't want to imply it's all good, just because it is pretty common.

Andrew R Stewart 01-31-14 09:44 AM

Having done dozens of such rear end respacings over the years i have little concerns. But each time i qualify the process to my customer with the "we can't be responsible for joint failure" clause. I have never had a bridge or other brazing let go, but i have refused to spread a few frames that I didn't feel good about.

The most extreme was the French Gitane tandem that started at 120 and ended up at 140. It also got canti bosses and a Shimano SE disk brake (this being back in 1980 not many options were around, but the Atom drum had to go). Andy.

unterhausen 01-31-14 07:59 PM

I'd like to do that to my tandem, but the rear end is pretty darn stiff.

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