roll centers

[racer-15]

i have read alot of info on roll centers. my way of thinking was the lower the roll center the easier it was to roll because like leverage with the weight being higher. but i read somewhere that asphalt cars run a low roll center on front and dirt cars have a higher roll center. so has my way of thinking ben backwards? confused on this because everything i read led me to thinking this way. any info is greatly appreciated. thanks

[RACEMAN]

Check with Bob Bolles in Circle Track magazine (print or on line). He's written extensively on roll centers and should be able to help you out. Roll centers is a tough nut to crack but patience and re-re-reading the articles will help sort it out.

[drtrkr244]

Generally, dirt cars have a higher center of gravity which is the top of the moment arm.This allows more weight transfer to the right side tires increasing side bite(traction). But like anything else in racing, you can go too far.

[Dirtrunner35]

The roll center is the result of the motion not the cause of the motion, or to say it another way, it is the result of forces not the cause of forces

[billy5]

explain please

[RACEMAN]

billy5,

The roll center has a static and dynamic location. In other words you can diagram the location when the car is at rest (best done with a software program) and when the car is in action and rolling over (the dynamic location).

I think the software will help you determine the location if the car is already built or use the software to design where you want the roll center to be.

[drtrkr244]

Generally, dirt cars like the roll center to be at the center to 6 inches left of the centerline. I have been using Bob Bolles software for years and found it useful on all types of dirt cars.

[Dirtrunner35]

Bob contradicts himself in that book, useful stuff in it but have to watch some stuff, needs to go in more detail on things