Front derailleur clamp

[ElyDave]

when fitting a front derailleur clamp should it be directly onto the tube?  Normally if I'm fitting something like clip on muguards or aerobars I'll use a bit of old inner tube as a shim to protect the paint as well as giving some grip. I've never fitted a derailleur clamp before so have no idea of the convention and you tube is bereft of specifics.

[robgul]

when fitting a front derailleur clamp should it be directly onto the tube?  Normally if I'm fitting something like clip on muguards or aerobars I'll use a bit of old inner tube as a shim to protect the paint as well as giving some grip. I've never fitted a derailleur clamp before so have no idea of the convention and you tube is bereft of specifics.

Direct to the tube (or a THIN sliver of electrical tape) - the clamp has to be fixed and tight to hold cable/spring tension-  a rubber shim wouldn't be a good idea.

[ElyDave]

Cheers Rob, I was thinking the same, confirmation always useful

[LittleWheelsandBig]

Metal shim or preferably nothing. Front derailleurs are brutal mechanisms and additional flexibility in the system is not a good idea.