I'm going to build my own radius arms for my EB. I like the twisted
arm design of BCBroncos. The cost is too high though. My design will also use the tie rod ends, but the front axle housing will have unique
mounting plates (with the tapered tie rod holes) installed instead of working around the c-bush design. My question is would there be any significant difference in mounting the arms parallel to the frame instead of the 10 degree kickout? Any good feedback is welcome, especially those who have done previous front end modifications...Thanks.

 

 

The biggest advantages of the kickout are from a leverage standpoint. The wider the attachment point on the axle from the kickout means that the axle takes less abuse from forces at the hub. It's hard to explain without a picture, but the less axle tube you have outboard of the suspention mounting point, the less leverage is on that outboard tube, and the less likely it would be to bend or break. Also, it more likely that the axle will remain perpendicular to the frame from front-to-rear forces. The best way to illustrate this is with an extreme case. Picture a single radius arm mounted in the exact middle of the front axle. If a force is exerted in the front of the left tire, it's going to have a tendancy to move the left tire back and the right tire forward. Now, since most axles are wider than the vehicle's frame rails, you have 2 options to get the radius arms wide enough on the axle. The first is to use some kickout to account for the difference in width of the mounting point on the frame and the mounting point of the axle. The second is to widen the mounts on the frame with additional bracketry, which brings up a second problem: tire clearance.

The second advantage of a kickout is that of tire clearance. In a design where the radius arms go straight back from the axle, and are mounted towards the outter ends of the axle, you will find your steering ability greatly reduced (the tire will rub on the arm). By having the arms come in towards the center of the vehicle as the go back, you get additional steering movement.

This info is based strictly on my experience and opinions and your particular situation might warrant a different design approach, but if you check most custom suspention arms they have some degree of kickout, for one or both of the reasons listed above, and perhaps others. With so many people doing it, I would feel confident that it's probably the best approach to maintain some degree of kickout in your design.

Just my $.02.

J.B. Hebert