I did this to my 12 and now on my 13, the pro use aluminum bars and the heat from your hand warmers will get sucked up especially when it is cold out, I thought mine were not working but after I corked them it was night and day and now they get toasty. First remove hand grips use air hose with pistol grip roll up the edge of grip shoot air underneath and the grip will come right off, remove the hand warmers from bars, just roll up the edge and peel them off they are pretty tough but just be careful. I purchased the cork in a package from NAPA the is only one sheet in the batch that works, it is the 1/16 in cork the complete package was only 9 bucks, the sheet is enough to do a couple sets of bars. Use a razor knife and cut the cork, I cut it 4 inches wide, use 3m spray glue and shoot the back side of cork and shoot the bars, make sure you mask off your sled as to keep the spray glue off your sled, let the glue tack up then just roll the cork over the bars cut a seem line using your razor knife. Now spray the inside of hand warmer with 3m glue and the outside of cork let it tack up then install the warmer on top of the cork. Now put your grips back on shoot the inside of grips with a little lubricant and use the air trick again roll the edge of the grip on and hit it with air on the inside of grip while pushing and twisting at the same time, when you get it on far enough you can hit it with air on the outside pushing and twisting at the same time once you get the hang of it they go on easy.
