UMI Roto-joints Rear LCA
 

Now, poly-poly LCAs are in my rear, but I'm planning to change them to UMI's roto-roto LCAs.
My car is complete for street use, and I don't like harsh ride.

How good roto-joints are for street use?
Are they harsher than poly-poly LCAs?

Re: UMI Roto-joints Rear LCA
 

When I went from rubber to Spohn Del-sphere (both sides), I didn't notice ANY increase in ride stiffness. The car did feel tighter. But not any stiffer riding at all.

Del-Sphere and Roto-Joint are basically the same thing.

Re: UMI Roto-joints Rear LCA
 

Thanks.

How are the noise and vibration?
No difference?

UMI also prepares poly-roto LCAs, so I suspect there must be some downside of roto-roto LCAs...

Re: UMI Roto-joints Rear LCA
 

None. Absolutely zero...... My city is all concrete roads with way too many potholes, cracks, and bumps. And I live near the center of the city. So it's not like I live way out of town on rarely traveled roads.

I owned the LCA and PHB for quite some time before putting them in. Precisely because I was worried it would ride too hard afterwords. But I gave up nothing for the increase in performance.

I'm not sure that poly would even ride any smoother. Poly doesn't have any movement. Roto-joints can rotate when they need to.

Re: UMI Roto-joints Rear LCA
 

Thanks for your info.
Now I've decided to go for roto-roto.

I think roto-roto ones are ideal because both sides of LCAs should have free movement to prevent bind completely.

Re: UMI Roto-joints Rear LCA
 

Btw, how about the maintenance cycle of roto joints?
Did you retighten them? If so, how long until retightening?

Re: UMI Roto-joints Rear LCA
 

UMI could probably answer those questions about their product.

However, they come with greasable fittings, so you should grease them once in a while.

The Delrin part does wear out, but then you just need the wrench and you can tighten them again.

Re: UMI Roto-joints Rear LCA
 

Hey guys.

Our intention with poly-roto vs roto-roto is to have the poly be potentially a little "softer" but if dual roto doesn't pose any problems in real world conditions that's a pretty nice testimonial.

We've seen street cars go a few seasons with no roto adjustment required where others (maybe with lots of abuse) need a quarter turn every so often. The Roto-Joint really is a cool piece and works well.

Maintenance is usually a few pumps of grease a few times per season.

If they do wear out, the Delrin pieces are $6 per end ($3 each side of the ball). As an example I get about one call per month, maybe less, with guys buying them.

Let me know if you have any questions.

thanks

ramey

Re: UMI Roto-joints Rear LCA
 

Thanks for the reply Ramey.

Just one question: How can you tell if adjustment of roto joints is needed?
Cluttering noise or something?
Or take them apart anyway and see if there is any play?

Re: UMI Roto-joints Rear LCA
 

If adjustment is required, you will see some play during servicing. Or if you lift with a floor jack you can see movement. Some Roto-Joint arms last many many years before needing tightened.