Rb5wishbone

[Duncan]

Is the um566 rear wishbone the same as a rear zx5fs wishbone

[paulj]

Hi Duncan, as I understand it all the RB5/ZX5 rear wishbones have the same geometry even the NGC arms are the same with just a machined edge to them. In fact I have heard that the NGC arms with the extension pieces for the shocks match up to the current RB6 arms but I think Tony or somebody with more knowledge would have to confirm this.

[RogerM]

There are 3 lengths of rear wishbone. I've covered this in the past many times.

The 3 identical "mid length" wishbones are UM521 / UM566 (these packs differ due to the front wishbone supplied) and LA272.

The 3 other "mid length" wishbones are LAW43 (same as above but machined for the drop plates), LA243 (three shock mounting holes, 3rd hole outside the others outer hole) and UM521-1 which is the same as UM521 but with only 1 shock mounting hole placed between the 2 found on the first three wishbones listed at the top of this post.

Short wishbones are found in LA255 (ZX5-SP & original FS2) and UM503 (Original RB5)

Long wishbones are in LA220 (Original Lazer ZX5)

each step is approximately 2mm and the length change is between the shock holes and the outer hinge pin.

Hope that helps! (maybe it's worth a sticky - any mods in???)

[Duncan]

Thanks roger that does help a bit.
I have my old rear fs2 wishbones left over from when I replaced them with the law43 on my lazer.
To save some dosh I was going to try them on my rb6 after you told me a dms to try some rb5 wishbones.
Will that work.

[RogerM]

They certainly will. They are LA272.

Use an Xgear red spring on inside hole as a starting point & mount the wishbones so the shock mounting loops are towards the rear. You will need to fit spacers or an old shock ball into the loops so as not to crush them and you will then mount the shock bottom eyelets behind the loops.

If you want to try it drill the extra hole it goes inside the existing inner hole the same spacing as the existing holes.
If you use those extra holes start on Xgear yellow or Losi pink rear springs.

To use the RB6 outer hinge pins you need to drill out the closed end of the wishbones & you will want 2mm outside both sides of the wishbone to centralise the hinge pin.

Start on medium wheelbase & work from there.

I find the straight wishbones help lock the rear end in a little & overall calm the car which as we discussed is what I'm looking for being no superstar.