I actually keep a roll of 1/2" wide black velcro ONE-WRAP handy, it sticks to itself as you wind layers to get to the thickness you need. Soft and will not mar handlebars or equipment. It will allow for compression for mounting rings to fit snugly.

We buy it in 75' rolls but 1'm sure you can get a smaller quantity or similar in Lowes or Home Depot




https://www.ebay.com/itm/VELCRO-BRAN...MAAOSwxONfRVzU

Also comes in other colors, great around the shop for many uses.