JunJun

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?

Reid Fleming

iTrader: (2)

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.

JunJun

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...

Reid Fleming

iTrader: (2)

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.

JunJun

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.

JunJun

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

Thirdgen89GTA

iTrader: (5)

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.

UMI Sales

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

JunJun

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?

UMI Sales

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.