Ya, it's always been an issue. I can't remember ever doing a ride on a mountain bike where I didn't feel something in my wrists afterward. It seems to be mostly an issue of back-sweep (my wrists just don't like to take hits when they're angled in at all). I'll adjust the bars so that the sweep is effectively maximized, but if that doesn't solve things I'll probably just switch to some bars with an 11 degree sweep or so (current bar is apparently 8 an degree).