Chainstays
 

Can I dimple Columbus Cromor chainstays in situ? Would be looking to p/u 5mm more clearence each. I was thinking constrain the oustside with a form and hammer or draw a disc wedge to widen. The disc would be tracked so no side to side deflection.

https://cimg0.ibsrv.net/gimg/bikefor...43bed8240f.jpg
https://cimg1.ibsrv.net/gimg/bikefor...e6bee3d049.jpg
Brain- can you do this? maybe. Have others? Yes. but 5mm of narrowing of the stay's width is a fair amount, about 25% of the common 22.2mm diameters or close to 33% of a typical ovalized section. Added to this is the placement of any stay bridge and it's access hindrance and stresses of initial joining. These reasons are why it's best to dimple before the build is completed.

Here's a couple of dimpling tools to draw ideas from. Andy

I saw your other thread and I'd say getting 5mm per side from an oval chainstay is going to be a big dimple. My experience with dimpling chainstays has been that the stay also bends at the point of the dimple. In the case of an already assembled frame, this means the stays will likely pull closer together at the dropouts and need to be reset to the proper spacing.

Andy, no one responded to my ask on the CR list, but are you willing to perform this operation for others? I have a 1982 Raleigh Int'l MkII I'd like to add a few mm each side internal clearance on.
Thanks, Jim C

Jim- PM coming. Andy