How much cushion does tank need on the backbone?

I'm switching tanks to a benelli knock off for my cafe project. If I leave the rubber cushions on the frame backbone the tank sits way to high, if I take them off and the tank sits right on the frame its way better, and I can work with it. I know that resting the tank right on the rails of the backbone is most likely a bad idea, but how much cushion do I actually need?

I wouldn't think you need a whole lot of cushion. Try taking an old inner tube and cutting some small strips from and it. Electrical tape the strips around the frame back bone and see how it looks. I think the cushions are there mostly to protect the paint on the frame/tank. The strips should give you the protection without more than 1/16"-1/8" of height.

Let me know if that works.

later, Doug

Actually, the most important function the isolators perform is making sure that whatever movement between the frame and tank does not wear a hole in the gas tank, and that whatever vibration the frame experiences, the vibrations do not make it to the tank with the magnitute that would cause weld failure of the tank. Remember, it's a GAS tank. Not the kind of thing you want to experience failure on.
At the very least, reinforced coolant hose 1 1/2 inch dia, split and forced over the frame.

If room enough, maybe a section of old foam rubber handlebar grip sliced down the side and fitted over the frame rail.

Or maybe some foam pipe insulation from home depot.

Thanks,

Foam pipe cushion and collant hose are great solutions.

Muddy wrote:

Thanks,

Foam pipe cushion and collant hose are great solutions.

Might be better to keep metal coolant hoses away from contacting the foam and tank; how about zip ties, or as someone else suggested, electrical tape?

The advantage to coolant hose is the fabric reinforcement in it. Won't wear through as fast.

pstrbrc wrote:

The advantage to coolant hose is the fabric reinforcement in it. Won't wear through as fast.

And also perhaps better tolerate the heat.

what about silicone? put a thin smear over the backbone, let it dry and try it. although i like the innertube and tape idea aswell

OKC_Kent wrote:

Or maybe some foam pipe insulation from home depot.

thats what i was gonna say! find some fore 1" pipe,it should fit fairly close;)

I used truck bed spray liner along the spine and under the tank. Still using the mounts but I think it has helped some of the vibration squeeks. Probably if you are resting the entire tank on the spine you will need something more substantial like what has been, already, suggested.