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Anyone cold setted a frame before?
Need to widen a Pompino from 120 to 130.
Thinking of a two way threaded bolt - tightening nuts one turn at a time (if that makes sense)
You will be there forever doing that. You also need to go beyond to allow it to spring back to the correct size.
Google sheldons instructions. Which involve a horsing on a plank of wood if I remember correctly.
Yep - good way if you don't have the proper tools is a block of wood - get a block that'll fit between the stays, and gently wallop it towards the bottom bracket.
You need to go over the width you're aiming for, because it springs back - usually 20mm or so but go slowly to get it right.
Edit: now I'm chuffed that I thought of the same technique as Sheldon Brown 😉
A carjack does the job.
Remember to bend the dropouts back to parallel or you'll find your rear axle will "walk" under stress.
I did mine (531c frame - though that only needed widening from 126 to 130) by standing on one dropout and pulling up on the other. No need for all these high tech blocks of wood 😉 Alignment checked using some bits of thread from dropout to headtube and measuring at the seattube. Don't think I touched the dropout alignment on that as it still seemed to be fine.
I've done the 120 to 135 with a block of wood before and it was a distinctly un-dignified method which made the mechanical sympathiser inside me weep. It did work though.
Does the block of wood need to stay wedged between the dropouts for any particular period of time?
The sheldon method is a long plank threaded through the stay resting one end on the seat tube the other end on a chair and pushing down on the frame.
The pictures on the Sheldon Brown web page are much easier to follow than the words
http://sheldonbrown.com/frame-spacing.html
I'd be worried about using a block between the stays as it's side loading the walls of the tube and could dent them. If I had to do it I'd want to shape the block so that the sides were parallel to the tubes and make half round channels to spread the load on the tube.
After cold setting, any ideas on bending the trackends so that they are straight? Thanks
Track ends will be fine my pompinos 135mm from 120mm done many years ago its still going strong after 10000 miles plus