XRAY - Model racing cars

I for some reason have just started breaking camber link adjusters. When looking at the angle of the arm, it looks like it is not straight. Can someone please help me as to why this could be. Also, do they make stronger replacements?? Any help would be great.

Are you running the XB8TQ or the older car? Also, I take it you mean the front upper A-arms and the turnbuckles that go in them? If so, take all the clips off the upper arms and work the suspension up an down a few times; let the upper arm settle where it wants to and use the clips to keep it there (The upper arms will split and the turnbuckle break if there is a bind in the upper suspension).

If you are running the XB8TQ, just use the same eccentric bushings in your upper roll center as you do for your kick-up. It's a no-brainer and keeps the upper arms parallel with the lower arms. On the older suspension geometry, the addition of the 2 degrees of in-board toe causes a slight bind in the upper arms if not shimmed properly with the clips. I used to shave about 1mm off the back of the arms to give them a little play when I ran the older geometry.

Yeah 490 it is the old XB8. I can't find where the bind is. It breaks them
half way in the arm, and of course you have to buy new arms also.

Twigs -

The only time I've ever seen one of the upper turnbuckles break was a well-deserved hit on a piece of PVC pipe. How many have you broke? I know Xray made some newer upper turnbuckles because in the very early days of the XB8, people were breaking them. You may just have some older turnbuckles. Pick up a new set and you should be good to go. I also used to run a bead of CA along the mold line of the upper arms when I ran the older car just as a precaution. I think it was David Joor who had a really good table for the older car where he listed what upper arm eccentric bushings to run to keep the arms parallel. I'll see if I can find it and I'll put a link here for you.

Like ajoiner posted earlier, your problem is that your roll center is not matching your kickup. If you adjust the kickup, you have to adjust the roll center and vice versa. They must be kept parallel.

I have broken 3 of these in the last 2 weeks. I am driving the old XB8 if that makes any difference.

Per David Joor.....

It isn't exactly spoken very clearly about how the upper arms should be positioned in relation to the kickup. So I would like to clear this up for everyone. Justin Mann and I debated over which setting was correct and I believe he won so here is the data that should give the least amount of bind to the upper arm through the compression stroke, I have found this to help keep everything functioning normally and the life of the turnbuckle is extended.
Kickup: Front Upper | Rear Upper 1down: 1up | .5up 1down: .5up | 0 1down: 0 | .5down 1down: .5down | 1down

So this is just an example, here are the rule of thumbs. Justin Mann and I built this up on the premise that 0 kickup placed the lower and upper hingepins were parallel using all 0 bushings. We also did testing on which caused the arms to be the most free (this is what we debated on, thanks Justin)

KICKUP | RULE FOR FRONT UPPER BUSHING POSITIONS 1up (3.0) | front bushing should be .5 lower than rear .5up (3.5) | front bushing should be .5 lower than rear or same 0 (4) | front bushing should be same as rear .5down (4.5) | front bushing should be .5 higher then rear or same 1down (5) | front bushing should be .5 higher then rear

This is confusing. So if I have 1down on top I need 1up on the bottom? Im lost with that chart..........

Here you go, this should help....

The second set of numbers is for the upper roll center.


1 up on lower (3 degrees of KU) = .5 down in front, 1 up in rear
.5 up on lower (3.5 degrees of KU) = .5 down in front, .5 up in rear
0 on lower (4 degrees of KU) = 0 in front, 0 in rear
.5 down on lower (4.5 degrees of KU) = 1 up in front, .5 down in rear
1 down on lower (5 degrees of KU) = 1 up in front, .5 down in rear

I just made this chart. It should make things a lot clearer.

I knew I should have believed Ralph when he told me you were ga......... special.

490, Thanks for all the help!!!!!!!!!!!!!!! This is why I drive an X RAY.....