Thanks for the quick reply.

I'm sure I have measured it right, but I guess the problem is, that I want to fit my brakes on a part of the handle bar that wasn't meant for brakes. The handlebar is actually 22,2 mm in diameter, but it gradually gets a little bigger 24,6 mm at the stem where it is mounted. And that is where I want to fit the breaks. I've cut off a lot of the handlebar to make it short and maneuverable, which is why I want the brakes as close to the stem as possible to make room for my hands.

But I guess what you're telling me is that it can't be done, and that I have to buy a new handlebar?