Originally Posted by
4wheeldrift
Its the distance between the center of gravity and the roll center. The larger the distance the more leverage = more lean. Lower roll center is going to be a greater distance from the CG. Good example would be off road cars. High CG, low RC. Motorcycles are the opposite. Low CG and very high RC, thats why they lean into a corner.
I use this software
http://www.rctech.net/forum/electric...alculator.html
For me having roll centers within a mm front to rear seams to work out the best for me.
I'll simplify that for you more...
Lower rollcenter = more grip / less response
Higher rollcenter = less grip / more response
What you need to be fast depends on the grip levels and layout but because the type R is ultra responsive at all times (due to chassis layout) I feel that with rubber low will always give better results. Foam however always has grip so I would lean the other way with high roll centers.
As mentioned above rollcenters are rarely the same front to rear. This is what is called the roll axis which is an imaginary line running between the front and rear rollcenters (sorry no pics). The best use for this line is to understand how much of your chassis weight is effecting each end of the chassis. I generally run a roll axis leaning towards the front which means that more weight is over my front wheels all the time giving greater grip at that end. This however takes some experience to handle as the chassis will "lose" the rear end in line with the amount you lift off the throttle.
Anyway setup is a pretty complicated thing but as mentioned a few posts ago is usually an adaptation of the chassis to suit the driver so once you find a happy medium setup there will be minimal change from track to track.
Hope I haven't confused everyone...