Outer Limits 4x4 Board

Has anybody used radius arms as antiwrap bars on a leafer? If so, how did it go?

The only prob I can see (not this may mean much) is that the bushes may allow too much give, though if this is a problem I can machine a solid bush or bushes. It just seems like a tidier arrangement to me, but thought that there may be a reason why people don't seem to do this.

ill add some pics of mine to the "the ufo" link in my sig prolly next weekend. in the meantime check out www.sjperformance.com.au (i think?). He makes a tidy bolt on kit.

Yep i had a range rover front arm in the back of my zook for a while worked well. Didnt get any axle rap with it.

I would think it would bind with the motion of the leaf sprung axle as it flexes.

X2.

The axle path with a radius arm and the axle path with leaves will be VERY different.

The the leaf does not invert on compression, it is possible to get VERY close to matching the axle path with a single rod, but not a radius arm. If the springs go into negative arch it's practically impossible as the axle path assumes an 'S' shape.

A radius arm will roll the diff around its pivot point so the pinion angle rolls with the arm, whereas leaves tend to keep the pinion angle roughly the same thoughout the range of travel.

It might work enough to do the job, especially with a shackle at the chassis end, but it will be compromised. Caltracs/oztracs look to be the most useful antiwrap solution for leaves.

Steve.

Thanks for this fellas! They are some really intereting points about the motion when the leaves flex and binding. Is the travel radius any different to that taken by a conventional anti-wrap bar, with a shackle at the end that the leaf is bolted to the chassis with? After hours of trolling I hadn't realised that this was a problem or looked at how it was solved... No doubt a good reason to have long antiwrap bars.

Looking at the Caltracks and Oztracks.... I'd not seen them before, and the concept looks interesting. I'm assuming that they work well with high articulation leafs? Also.... Are they something that would also work going to the top of the axle rather than the bottom - just thinking clearance. They look like they'd be fitted both sides and easy to package into the 4WD.

my zuk is running oztraks as of saturday... took it for a spin sunday and with my flex (see link to "the ufo") theyre going just fine. They dont bind up at all and hang down less that when the zuk was SPUA.

even with a large amount of metal protruding down from the shackle end (i still need to trim off the un-wanted lower mounting hole) i still didnt manage to bash it on any rocks. (and i was trying to!).

all my axle wrap is gone now - its like driving a completely different car both on an offroad!

I've toyed with the idea of caltracs running off the top of the axlehousing (SPUA) back to the back of the leaf and I think they'd still work, it's just back to front. Some trickery would be required to get the mechanism to fit between the shackle and the spring, but that's no biggy.

I don't like the idea of them below the spring/axle at all.

Steve.

PS the radius arm will behave the same as a "sams offroad" style traction bar with 2 points of location on the axle. My comments about getting the "sweet" point with very little bar longitudinal motion applies to a single tube only, which are only moderately effective. once you triangulate the bar vertically, the traction bar will ALWAYS fight the springs and some binding will occur, although the longer the bar the better.