For what it's worth, I read some post by a fitter somewhere that most people run bars that tend to be on the wide side for them which causes basic problems like hand numbness, shoulder pain, etc. I never had issues with my 40cm bars but when I picked up a pair of 38cm bars for dirt cheap, I tried them and they felt a lot more natural. Bottom line, you might be surprised (or not) when running bars you thought were way too narrow for you.