I've always covered the upper (thicker) parts of my Gitzo tripod legs with rubber insulation tubes, which make carrying the tripod easier, insulates against the cold, and protects the legs from dings. When it was time to replace the tubes, I went online to see what was available. (The foam pipe-insulation tubes sold at Lowe's are not of sufficient diameter for my tripod.) B&H sells a set of three tubes for about $50, which I thought was way too expensive, so I did some further research. What I found is a local heating and AC supplier, Baker Distributing Co., that sold me a six-foot long tube of closed-cell rubber that, cut to length, works perfectly. The cost? $4.05, including tax.
The tubes come in different sizes, so you'll likely find one that works for your tripod. To determine the size you need, measure the outside diameter of the upper section of your tripod legs and then get a tube with an inside diameter that's a bit smaller. For example, my legs measure 1 1/4 inches, so I bought tubes with a 1 1/8-inch diameter. They fit snuggly but not too snuggly, so they were easy to put on. (You will have to take the lower sections of each of your tripod legs off to fit the tubes over the upper sections.)
I've included a photo of the new covers, where you can see how nice they fit and look. If you need help buying or fitting on the covers, just let me know and I'd be glad to help you.
Baker Distributing is at 916 West Street in C'ville (295-2178). You should call ahead to see if they have the size you need in stock.
