I buy / repair / sell bikes. I found an older TREK 730 that was in fairly nice shape. One problem it had was the grip shifters rubber had degraded somewhat where they felt "sticky". Not bad, but not comfortable to use, and I did not really want to replace the shifters. I knew that wrapping them in tape or some such would not last for long. I found a good easy solution. I found some large shrink tube on Amazon that slipped over the shifter, and used a heat gun to shrink it to the shifter surface. Trimmed the edge with a razor blade, re-installed the handlebar grips, and have an easy and relatively cheap repair.