Modular ring roller design

I’ve had an idea rolling around in my head for a while and decided to spend some time putting it together. I use 12mm tubing for seatstay bridges and I like them curved. In my old workshop we had a ring roller. But it was a big heavy old thing and took up a lot of space. I can get about 25 bridges from one 2m length of tubing so normally I bend enough tubing for about 50 bikes at once. That means the bender gets used very infrequently. My current workshop is very small and I really value all the space that I have available so buying another ring roller was not something I wanted to do.

I use a fabrication table (the type with a grid of holes) which is very heavy so I figured I could make use of that mass and make a modular roller/bender with that as a base.

The roller is made up of 4 main parts, 2 static rollers, one adjustable roller and a driving screw. The grid on the fab table gives me enough adjustability for a tight bend and the rollers themselves can be swapped out for dies to fit other dimaters of tubing.

I’m really happy with the way it works but I’m especially happy with the amount of space it (doesn’t) take up.

There’s a little video of it in action here : Instagram


Brilliant idea! I never thought of using a roller to make bridges. That would speed things up a lot and produce much less waste material.

what wall thickness is your 12mm tubing?

Do you think this would be possible in 16mm tubing?

The 12mm tubing is 1mm wall thickness. I find it quite hard to source so I don’t worry too much about the wall thickness. A lot of the tubing is sold as 12mm but actually turns out to be 1/2" which doesn’t work in the dies I have.

I’m sure it would work fine for 16mm tubing.

I used pulley bearings in this as they are easily available in 12mm and effectively are a die and bearing in one but if you couldn’t find a 16mm pulley bearing then making dies would be pretty easy.


That’s killer!

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Well done! How about adding an electric drill for the driver?

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First thing I did!


Great minds think alike!

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