4-link, triangulated lowers

I searched for a while but can't find what I was looking for. What is it called when the lower bars are triangulated on a 4-link? This lowers the roll center, right? What else will it do for the suspension? Any benefits or downfalls to running a setup like this on an adjustable suspension compared to a standard triangulated link setup?

satchell link i think is called search on yahoo i found lots of info on it..a lot of road race cars use them

Yes, Satchell Link...

It's major advantage is that it has a low roll center. You can "dial in" the upper bars to create roll under or understeer, but you can do that with any 4-link system really. Any efficient a-arm front suspension design has a roll center that is right at the ground and in some cases below the ground. So the lower you can get the rear roll-center the more ballanced the vehicle is.

It also has alot of anti-squat with roll understeer. What are the disadvantages Max?

Every suspension design has it's limitations. Though I do feel that the Satchell link has less than others.

Anti-squat is not necessarily always created by the Satchell link, nor is roll-understeer. The angle of the bars (from a side view) at drive height is a major determining factor or roll-steer and anti-squat. More anti-squat will typically generate more roll-oversteer and vise-versa. As I stated before, by angling the upper bars in or out will also over and understeer.

The one major disadavantage would probably that the lower bars need to as wide as possible on the rearend and as narrow as possible at the chassis, not the other way around. That isn't always easy to accomplish, with the support that the cross member will need to live through the streeses seen by a hard cornering vehicle.

roll steer or anti squat ...
does any of these have anything to do with body roll?

So the 4-link cannot start at the pumpkin and go out to the frame? Why is this?

excellent question. thanks for asking- cause i learned a bunch from the answers supplied by you other guys. thx~

Originally posted by stkflrd 73



roll steer or anti squat ...does any of these have anything to do with body roll?



No. The roll-center is the point that the chassis rolls around the suspension, that would be at the instant center of the lower bars. And that brings up our next question...

Originally posted by TwistedMinis



So the 4-link cannot start at the pumpkin and go out to the frame? Why is this?

The bars comming to a point at the chassis makes the roll-center at the chassis, by keeping the roll-center at the chassis keeps it from moving around (in relation to the chassis.) If the roll center were to be at the rearend housing, as the suspension moved up and down so would the roll-center, which can make for a twichy feeling ride in bumpy corners.

Does the same thing apply to triangulated upper bars? Or is it just in a Satchell link? If so, why is it different?