23-07-2020, 10:46 AM
I have fabricated radius arms on two of my cars. The two main reasons for doing this is to get better rigidity under hard braking and to be able to easily adjust caster angle. Can't really see that either of these would be a priority for trials. But here's the radius arm setup on my special which has a Big Seven front axle:
![[Image: 40538556054_eb7a22fc3b_z.jpg]](https://live.staticflickr.com/869/40538556054_eb7a22fc3b_z.jpg)
The tubes are 3/4" 16SWG CDS, the single "ball joint" is a 1/2" teflon lined rod end mounted to the cross member. the reduction in axle twist (i.e. movement) under braking was really noticeable when I did this mod. Doing something similar with a Seven front beam would really need the "batwing" bracket to be tied into something other than the big bolt hole to prevent it from rotating. Either a shock absorber mount hole or the other bolt hole if you have a Girling style front axle would do.
The tubes are 3/4" 16SWG CDS, the single "ball joint" is a 1/2" teflon lined rod end mounted to the cross member. the reduction in axle twist (i.e. movement) under braking was really noticeable when I did this mod. Doing something similar with a Seven front beam would really need the "batwing" bracket to be tied into something other than the big bolt hole to prevent it from rotating. Either a shock absorber mount hole or the other bolt hole if you have a Girling style front axle would do.