Ultra thick tubes change 04 handling/performance?

jmunne

i race in rocks with 12lbs front and rear. i think 17lb is very, very safe.

for me the whole idea of the HD tubes is to be able to run a lower tyre pressure in safety. you could run 10lbs but i think there is a small chance you would still have a puncture and i don't want to be the one that is guilty of giving you that!

i didn't play with the adjusters at all.


regards

Taffy

i run as low as 5lbs on a muddy day and trust that i manage the one rock i hit or have luck. i normally run 10-12 all the time. i never run over 12 with HD tubes. that's the whole point of having them.

the thing to look for is the roll of the tyre. i've known michelin to be written upside down on the excel wheel rim!

regards

taffy

Hi John,

What kind of tires are you running?? That's makes a huge difference.

I race out here in the local desert and there is allot of rocks, sticks, cactus, etc.... I run Pirrelli MT 18 HD tires front and rear with the bridgestone HD tubes. I have found that 13 psi in the front and 11 psi in the rear. I tried 12 in the front, but, on some rock hits I could feel the rim getting whacked with the tire in between, so I went back to 13. I also run that green slime stuff in my tubes as well, so just in case I run over a barrel cactus I won't get a flat b/c of a slow leak.

I think the whole reason you were getting pounded was b/c the tube tire combo was so stiff, you weren't getting the benefit of the tire flexing.

Taffy has a good point about the mich imprint on his rim. I have found that when the pressure is right, you will see that the edge of the rim next to the tire is polished from the tire laying over on it. It can even be polished a little ways down from the edge, say a couple of mm's.

Good points Daleo.

John,
I tried to warn you that 18lbs is a bit much.

i was exagurating about the name upside down but you do find the rim all polished up near the edge where the tyre has folded over.

on roadracers though, what i said is literally true, the name of the tyre IS upside down on the whole rim face!

regards

Taffy