6th Coil Length
I am running swing arm with a pull bar and I have some clearance issues with the 6th arm because of the excessive movement of the arm. Since there is no 5th coil I was wondering if I could just shorten the length of the 6th arm and run a stiffer spring? Or will this cause other effects.
I haven't ever really tested the length of the arm on a 6th coil, this I what I would guess it will do:
The length of the arm really is only going to effect the rate of the spring for the most part. The piont that the 6th coil is attached to the frame is the more important one as that is where it is pulling down on the car. Farther to the front it will load the front tires more and farther to the rear it will bias the rears more.
I don't see it making a huge change unless you moved it a far ways, if your happy with the car I would shorten the arm but keep the 6th coil in the position it is in now and just let the chain run back as it goes down to the arm. However you will need a 6th coil that can pivot front to back so it pulles on the spring in line so not ot side load the 6th coil and cause a bind.
You will have to slightly adjust the spring for the length of the arm change
Are you having clearance problems under throttle or under braking?
Is the ladder bar braced side-to-side on the frame-rail or is it tied back to the axle housing?
If the ladder bar is shortened considerably, it will make the rear of the car squat more off the throttle.
We had a problem on a Rayburn where the end of the ladder bar would hit the 6th spring mounting under acceleration. We shortened the ladder bar enough to clear the 6th spring mount, but we still would bind up the stabilizing link that ran to the frame-rail. That's when we had to run the stabilizer link back to the axle housing. That seemed to work pretty well.
We have since gotten rid of the ladder bar all together by using a 2-way pull-bar, which is nice, because we don't have to unhook the pull-bar when scaling.
I thought about that but I'm afraid to. I almost like the 6th there just for safety relying on just the pullbar scares me. I had my 6th coil break last year and tore up a lot of stuff. But I run a pullbar on a 4bar car (pierce) and maybe the Swingarms are a little more easy on pullbars? I still think about trying it someday. Timmay do you think that 2way is strong enough, what brand is it you use?
We build our own pullbars. If someone would have built & sold a Late model pull bar that didn't bottom out the spring, and could work under braking too, we would have bought one along time ago.
Hummm I guess I'll wait until you start selling them on here then?
Westling, I don't have any intentions on getting in to that business. Check your PM.
Just run a chain to catch the arm incase the pull bar lets go. That way if it does brake the chain catches it and you may break less parts.