3M makes an adhesive tape called "Safety Walk Indoor/Outdoor Tread". It looks like grey spray in bed liner material for a pickup but it comes in strips or on a roll. It is a rubber based saftey tread that provides great grip on the bike and protects the frame from your boots while not tearing up your boots like a sand or grit based product would. I bought the 2" wide by 5 yard roll for about $15, which is enough to do at least a dozen XR650Rs. I used approx 12" of tape on each side of my bike from the curve that goes under the seat to just above the peg. Just clean the frame with contact cleaner, trim, and stick. I first saw this done on Tim Ferry's Factory Yamaha YZ426. It is cheap, works great, and the only thing it does not do is provide any extra protection for the rear brake master.