Originally Posted by
jbonamici
I know what you're saying. As you can see in the picture, the edges that would have tape contact are not only brittle but also discolored, and they have a little sheen. It really does look like old shellac, which got me wondering. I don't know enough chemistry to state that shellac affects rubber, so who knows. Anyway, there was a thread the other day about 303 Aerospace protectant - I'm going to get some of that and see what happens. I figure it can't hurt.
The shiney stuff is not necessarily shellac.
The top surface of gum hoods do get really shiney in some cases as they dry out, almost looking like hard plastic (instead of the velvety soft texture that most of them leave the factories as), forming a sort of stiff crust that then eventually darken and crack up into smaller scaley surface flakes before craking all the way through. Rotting is the best way to describe how hood desintegrate with time. The gum lever hoods on my Spidel Brake set is just starting to develop similar hints of minute cracks and shineyness at the very edges of the hoods too, aganst the bar, and I'm 100% sure that they werenever anywhere near shellac. I think I'll just trim the feathery dried edges with a razor to clean them up and maybe arrest/slow down the rot a bit(?).
Good luck with your search!
BTW, The white hoods I have on my Aero Gran Compes seem to be lasting much longer than "natural" gum lever hood usually do. In fact, I don't really see any rotting at all, save for a couple of minute cuts near the lever pivots most likely caused more by stress when I removed and re-installed them when changing bar tape and not rotting. I think the colored ones are more like silicone material and not gum rubber. That's why maybe mine are in good condition, despite their 20+ year use on the bike. Mybe you should consuder finding the colored ones instead.
I think our only salvation for C&V levers is someone could make casts of the old, now hard to find lever hoods and mould new ones made out of silicone instead.
Chombi