problem with spring behind axle

on my model a iam setting it up with spring behind.i have total perf. spring behind batwings on my i beam i want to run the tie rod in the back but it hits the spring shackles in the turn pos.can the arms be lenghtend to clear and can you weld on them.i dont want to run it in the front kills the look.

 

Can you post some pix? Spring-behind-axle set-ups usually run wishbones, not batwings. My pea-sized brain is having a little trouble visualizing this... Take a look at the Rolling Bones front ends, or serach 3W Larry's posts. He ran a lot of pix on this kind of set up.

 

Detonator is correct...there is a fair amount of information on this subject already. His reference to "batwings" indicates a 4 bar, and that might be part of your issue.

My only comment concerns the tie rod. You suggested that you don't want to run it in front because it kills the look...I agree, but not for that reason...it will very likely kill YOU.

The tie rod is in the rear because of a very important steering geometry referred to as "Ackerman". Ackerman suggests that if you draw an imaginary line from each king pin center thru the corresponding tie rod end (steering arm) center, then that line should intersect at, or about, the center of the rear end.

This ensures that the inside tire turns a tighter radius than the outside tire in a turn. The alternative, which is what happens when you place the tie rod in front of the axle, is that the outside tire turns a tighter radius than the inside tire.

Needless to say, that is NOT a good thing.

My $.02...don't place the tie rod in front of the axle because it "kills the look". The look is meaningless. Don't do it because it's the wrong thing to do. Form must ALWAYS follow function.

 

I think people forget...tie-rods don't have to be straight. If you do it right, you can have a tie-rod with just the right bends to clear things without giving up any strength.

 

Frank's right, but remember that a tie rod with doglegs in it is difficult to adjust. Tie rods have left hand and right hand rod ends that allow you to dial in your toe by just rotating the rod. It's a little more difficult (or impossible) to rotate a tie rod that's not straight. Let's see some pix of what you've got going....