View Full Version : PN 1 degree upper arms

2012.10.05, 09:01 PM
I have wondered this because when you combine the low down knuckles with the 1 degree upper arms there seems to be quite a bit of slop in the front suspension. To the point there if you don't put any shims in it the front springs can and do fall out. Does anyone else have this problem?

I will post pictures for reference when I am at my box.

Started a new thread since this is technically not about the low down knuckles.

I noticed that the 1 degree arms produce a large amount of slop for the front springs. What are most people doing to eliminate this giant gap where the springs are sitting? The springs can actually fall out while racing and they do since murphy and his laws are apparently in my car.


If I add shims to the underside of the knuckles then we run out of king pin travel.

Any tips or pictures of your setup would be appreciated. This car runs in a 70T stock class.



2012.10.05, 09:58 PM
I was running the Atomic reverse kingpin setup for a while with a Reflex tower bar and had a similar issue. Solved it by a preload plate under the springs - something like the Atomic MR3-027. It looks like youre using a PN plate - is there room for narrow spacers/shims around the bottom to raise the springs a little?
I just looked little harder at the pics. Do you not have any shims at all either above or below the knuckle? Check your ride height compared to stock. I would have expected you would probably need some shims below the knuckles to lower the front end a little (which would reduce the travel yes - how much travel do you expect to have, and at full travel how close is that chassis to bottoming out?). You can also shim above the knuckle. It will affect camber - which may be either good or bad depending on what youre trying to achieve. Shims above the knuckle in a normal (as opposed to a reversed) king pin setup also cause more friction against the king pin because they will be rubbing as the knuckle and the shims have to move up and down.
One place you might want to look at for some pics and info about the setup you are using. http://tinyrc.com/forums/blog.php?b=270. Good luck let us know how you go.

2012.10.05, 11:35 PM

I will give Brian's setup a look. I do have the thin stock shims that are normally included in the standard kit setting. They are those very thin black ones so they are probably hard to see from this picture.

2015.11.07, 10:05 PM
Are these upper arms compatible with