I am riding a '08 Rockhopper Comp Disc 23" but the problem I keep having is after about 30 minutes of riding around my hands go numb. I've changed my seat to a WTB Power V and moved it from front to all the way back. Still going numb. New grips, ODI Rogues. Fox Sidewinders for gloves. No change. Re-angled the bar so the handles are more level versus rising up at the ends. Still nada. Should I get a straight bar, would that help? Or am I just too heavy, 290# and 6'5"? Many thanks for any advice.