guy153

Thanks! Those flats won't do any actual harm. I got one of these type of benders:
https://www.ebay.co.uk/itm/352850193...EAAOSwWI1dyMJf
and it will probably work quite well. I just didn't have enough time to experiment with it because I only had one pair of stays. So I bent them near the top, didn't like it, and so cut them down and went with straight.

But I have since used this to make a rando rack out of 1/2" 16 gauge stainless and got nice smooth bends.

I packed the SS with sand but not sure this is actually a good idea. This kind of bender isn't really meant to be used with sand and I didn't use any on the rack.

Devin Rickey

One of the things that kept me from trying to get a bender on the seat stays was the taper. They were 9/16" give or take at the bend point. So wouldn't really have been a good fit for most of the benders I had access to. I would think your bender would do fine guy153 !

MassiveD

You can also fill with water and freeze which is a no-setup option in the frozen north.

I have a proper tube bender, and I also built a bender for racks that works great in different sizes. Suppliers sell these mandrels for cheap that are designed for welding to sprockets on machinery heavier than bikes. I just used those for dies, by cutting grooves in them on my lathe.