My elderly aspiring touring friend bought some Brompton butterfly bars. They didn’t match his stem diameter. He popped back to the shop to be told his stem diameter was 25mm and his bars 24mm.

Both are dimensions I’ve never heard either of before. He was told he’d need a 1mm shim.

Does such a thing exist or are the dimensions wrong?

The stem was similar to this. It was fitted to a Dawes Karakum, I’m not certain of the year model.

Beer can is about 0.35mm thick, wrapped right around makes about 0.7mm. Binder bolt should take up the slack.

If not, nothing lost!

Doh ds like it might be best to have a proper measure up and see what’s what
But cans do make good shims and most drink cans are coated to resist rusting

http://sheldonbrown.com/cribsheet-handlebars.html

http://www.sjscycles.co.uk/stems-accessories-dept350_pg1/

the page on the sheldon brown site is interesting. So many that are so close to one another
Also interesting that 31.8mm-22.2mm (ie 31.8mm MTB bars) and less so the easton 35mm-22.2mm sizes aren’t on there. Content getting dated on therE?

You need a special shim from the private stock of Baron Alfred Krupp

But cans do make good shims and most drink cans are aluminium which doesnt rust

FTFY…

Steel drink cans are thinker IMO just depends how much shim you need

Shim bodgeing is the way forward.
I managed to shim a lower headset cup with a beer can ok, on a flared head tube.