Old ****s like me will remember KB re-rolling (& presumably drilling and eyeleting) MA40 rims in the 80s for super light rims with a tyre profile that would have your canti pads slashing your tyres before you could say “brake set up”.

Anyone know about the machines that roll an extrusion into a rim? Must be something with 3 rollers or something?

Us old ####s have to stick together.I remember it taking 3 people to mount a Ground Control S onto an MA40!

You can get ring rollers/tube benders quite easily but they are pretty expensive. These are nice. IIRC when Keith started he was bending scrap rims from the skip behind the Specilaized factory. 36h 700s rolled nicely in to 32h 26″ rims. I seem to remember he made a jig to hold them but, basically just put a little bend in at every hole then moved on to the next one. He did that in his living room, because it seemed more sensible than the kitchen.

Interesting. Not sure if it’d work down to 16″ though 😛

However it gives me faith that farting around in my bedroom (I shaer my flat) WILL make me the next KB.

It’s going to be hard to do it that small. For a given rim section, the smaller the desired diameter the harder it will be to do.

I like your thinking – I’ve been lusting after this rim drilling device: http://www.wheelfanatyk.com/blog/keene-rim-drill/

Brompton wheels are well lardy. I reckon a 1-20 hole Open Pro would work fine – the rim would be 250gm

If saving weight is the aim, I reckon a Brompton rim would fit on the big faceplate for my horizontal mill – Could just shave it down.

Or drill fatbike-style extra holes in it.

700C 36H and 26″ 32H rims would both roll down to 20H qy” rims just about perfect

There’s quite a good video of it here;

https://www.youtube.com/watch?v=dQw4w9WgXcQ

That is a brilliant video, shows exactly what’s needed.

Us old ####s have to stick together.I remember it taking 3 people to mount a Ground Control S onto an MA40!

I remember having to run about 60 psi in my Ground Control S’s to stop the tyre falling over on the rim and to prevent snakebite punctures as I was paranoid about having to get the tyre off the rim on my own!

My wheels were hand built by Cliff Pratt in Hull. The rims lasted until about 2008 when I tacoed the rear. The MA40s were pretty well unrideable until V brakes appeared. I remember hooking a canti under the rim during the time trial stage of the Boltby Bash. It’s amazing what feats of strength one is capable of when against the clock! I managed to wrench the canti back out and finished the last half mile with the rear brake disconnected.