This is very common and is due to pressure on the ulnar nerve, as you rightly say.

It's pretty frightening when it happens badly - i once called my doctor in a panic thinking i had some kind of severe arthritis attack. It passes in a few days of no riding with no more handlebar pressure.

The fixes seem to be: A bike fit, moving your hand position regularly, and wearing padded gloves.


Good luck, but don't worry and it's unlikey to be something you need doctors to start messing about with*

*Disclaimer - I'm not a doctor so don't take medical advice from some guy on the internet.