Quick question for you guys. Have the heated grips on my XC but they're worn out and too skinny, which make my hands hurt and cramp after a while. Want to buy new grips, but all I find have a note "won't fit XC with heated grips" or something similar. Are the bars used on the bikes with heated grips a different diameter, or some the wires go within the bars, or what's the deal? Anyone know?