Triumphrat

NewOldSkool · 10-14-2007

Can anybody explain alttle for me. I tired the search, but most are about the F3/F2 mods And people are already well past any of my knowledge in those posts. Like what are cartridges? And what are the benifits of removing/eliminating them? And do you have to remove them when using progressive springs?

Thanks
Mondo

Kurtis · 10-15-2007

Someone may wish to correct me on this, as I'm not definite...

The Bonneville/thruxton/scrambler forks all use non cartridge damping systems. It's basically a piston with some holes in it to let oil past at a rate determined by the size and number of holes.

The problem is that these holes are a compromise. If they are small then the damping rate increases, giving smooth control over slow movements, like road undulations and dipping on the brakes. but this means fast movements like pot holes are massively over damped and there's greatly reduced suspension movement. Which rattles your teeth out.

Vice versa, large holes mean good damping on bumps, but wallowy cornering and it'll dive like Greg Louganis on the brakes.

Catridges seperate out the high and low speed damping using holes and sprung shim stacks. The shim stacks cover the holes and slow movements have high damping rates. A fast sudden movement pushes the shim stack out of the way to allow lots of oil through, and hence comfortable damping.

Any professionals might want to add or modify the above if it's wrong...