Found some thin foam tubing. Guessed at the size, and I was right. Sprayed a little silicone inside and it slid on to the existing grip, no problem. It really helps end the higher speed handlebar vibration. and has a nice gripping surface. This 12" long piece was .50c each. I found it in a surplus store. The other side benefit is because I have very large hands I don't cramp up, now.