Founder's swivel joint vs UMI Roto joint
08-14-2012, 09:28 PM
#1
Founder's swivel joint vs UMI Roto joint First off, I don't want any brand bashing or humping 
I'm familiar with how each company just from reading other threads. I certainly welcome UMI and Founders to inject their input.
What I'm looking for is a direct comparison between their two rotational joints and the pros/cons of each design. I plan on redoing pretty much all of my suspension next year hopefully (money permitting) so I may have more questions or feedback requests regarding other components later (mostly the front).
The main purpose of my car is a summer daily driver that I want to handle well without adding too much NVH to the ride, although I can't imagine it getting much worse than it is already. It bangs around under there pretty good right now
Comparing Founders to UMI the main difference I see is UMI uses a delrin race while Founders uses a poly race. This is where I have questions.
1) Which type of bushing material will hold up best for daily street use, or is there no difference?
2) How does the harshness/noise of each compare to rubber bushings? Any notable difference between the delrin vs poly races?
3) Is it at all to my advantage to have a rotational joint on both ends vs just the axle end?
4) Any reason to get adjustable with my 10 bolt? Are adjustables required for other axles?
5) The Roto joints say they are rebuildable. Are Founders swivel joints rebuildable?
FWIW I'm thinking 17x9.5 wheels with 275 tires front + rear, Bilstein shocks, and either SLP springs or Stranos - guess this will depend on how it looks at stock ride height with the new wheels+tires, how much I want it to drop, and what kind of ride each set of springs would give me. Also considering a watts link vs the traditional panhard. Front end I really don't know yet but that's for another thread later.
Thanks guys!
I'm familiar with how each company just from reading other threads. I certainly welcome UMI and Founders to inject their input.What I'm looking for is a direct comparison between their two rotational joints and the pros/cons of each design. I plan on redoing pretty much all of my suspension next year hopefully (money permitting) so I may have more questions or feedback requests regarding other components later (mostly the front).
The main purpose of my car is a summer daily driver that I want to handle well without adding too much NVH to the ride, although I can't imagine it getting much worse than it is already. It bangs around under there pretty good right now
Comparing Founders to UMI the main difference I see is UMI uses a delrin race while Founders uses a poly race. This is where I have questions.
1) Which type of bushing material will hold up best for daily street use, or is there no difference?
2) How does the harshness/noise of each compare to rubber bushings? Any notable difference between the delrin vs poly races?
3) Is it at all to my advantage to have a rotational joint on both ends vs just the axle end?
4) Any reason to get adjustable with my 10 bolt? Are adjustables required for other axles?
5) The Roto joints say they are rebuildable. Are Founders swivel joints rebuildable?
FWIW I'm thinking 17x9.5 wheels with 275 tires front + rear, Bilstein shocks, and either SLP springs or Stranos - guess this will depend on how it looks at stock ride height with the new wheels+tires, how much I want it to drop, and what kind of ride each set of springs would give me. Also considering a watts link vs the traditional panhard. Front end I really don't know yet but that's for another thread later.
Thanks guys!
08-14-2012, 10:40 PM
#2
Quick few statements as I'm on my phone and can't see the whole thread real well...
Our Roto-Joint uses Delrin as you mention. They are very quiet when properly adjusted and properly lubricated. Somewhere between poly and rod end concerning NVH, closer to the poly.
Of course rubber is the quietest and lowest NVH but also has vague road feel.
We have Roto's on DD's with 50k miles and no trouble. They are adjustable, easy to maintain and rebuildable.
Our poly/Roto combo arms are a nice compromise between comfort and handling. A car which is fast on them won't get a ton faster on Roto/Roto but every little bit of articulation helps in certain situations.
I'm not familiar with Founders product but would be happy to answer any questions you have about ours.
Thanks for including UMI in your comparison.
Ramey
Our Roto-Joint uses Delrin as you mention. They are very quiet when properly adjusted and properly lubricated. Somewhere between poly and rod end concerning NVH, closer to the poly.
Of course rubber is the quietest and lowest NVH but also has vague road feel.
We have Roto's on DD's with 50k miles and no trouble. They are adjustable, easy to maintain and rebuildable.
Our poly/Roto combo arms are a nice compromise between comfort and handling. A car which is fast on them won't get a ton faster on Roto/Roto but every little bit of articulation helps in certain situations.
I'm not familiar with Founders product but would be happy to answer any questions you have about ours.
Thanks for including UMI in your comparison.
Ramey
Last edited by UMI Sales; 08-15-2012 at 07:24 AM. Reason: typo
08-14-2012, 11:37 PM
#3
Thanks Ramey. Good to hear on the mileage. I was suspecting the poly/roto vs roto/roto to be like you said but wanted to be sure. While I want the car to handle well and have the axle articulation necessary I'm also not trying to be a pro racer trying to get that last 1/100 second on a lap time or anything 
08-15-2012, 11:31 AM
#4
Copy & Paste Moderator
If you want to cut down on NVH, I'd say get the Poly/Roto instead of the Roto/Roto. But since you are dealing with a noisy rear anyway, you can just stick with Roto/Roto and it won't be any worse than you have now (possibly better... certainly better than rod ends, I have experience).
Either way, if you are spending the money on new LCA, get adjustable. The Roto/Roto ones are double-adjustable meaning that since the two ends are adjusted in reverse of each other, you can adjust them on the car by loosening the lock nuts and turning the bar. That makes adjustment/alignment very easy. The alignment shop I took the car to loved them.
The rear of my car was slightly off with the stock LCA so the adjustable ones fixed that.
Either way, if you are spending the money on new LCA, get adjustable. The Roto/Roto ones are double-adjustable meaning that since the two ends are adjusted in reverse of each other, you can adjust them on the car by loosening the lock nuts and turning the bar. That makes adjustment/alignment very easy. The alignment shop I took the car to loved them.
The rear of my car was slightly off with the stock LCA so the adjustable ones fixed that.
08-18-2012, 06:36 PM
#5
Good point on the adjustable. Especially, thinking forward, I might be needing a different rear end down the road as I do want to drop in an LS3 + T56 when the current engine wears out.
I'm just trying to juggle multiple projects that vary in cost next year. Tires + wheels, suspension work and body work for the car, plus tires at a bare minimum for the truck but probably will need more as it is getting up there in miles, plus I also am starting to window shop for a house. Ouch.
Oh, I don't want to confuse anything, I don't have rod ends. I'm still on original everything (except shocks) and everything is very well worn out and loose back there. When rubber bushings bang around you know they are dead
I'm just trying to juggle multiple projects that vary in cost next year. Tires + wheels, suspension work and body work for the car, plus tires at a bare minimum for the truck but probably will need more as it is getting up there in miles, plus I also am starting to window shop for a house. Ouch.
Oh, I don't want to confuse anything, I don't have rod ends. I'm still on original everything (except shocks) and everything is very well worn out and loose back there. When rubber bushings bang around you know they are dead
08-19-2012, 12:00 AM
#6
Oddly, I just went through this.
I had poly/poly box for a few years. Terrible combo, no articulation, binds etc
I bought the Founder's poly/rod combo this spring, then a few weeks later put on the delrin roto joint.
The founder's rod is a QA1 piece, nice, but "loose" is how I'd describe it. It gives very good articulation for the rear axle. Noise is definitely up compared to poly.
The roto joint I had to "cut" an inch of thread to fit it in since the roto joints are inherently larger. They are quieter than the QA1 rods and since you can adjust, they are tighter and more absorbing of impact. It's been 5 months now of DD and they have not come loose. I put a bit of blue loc tite on the locking bolt for the joint.
I had poly/poly box for a few years. Terrible combo, no articulation, binds etc
I bought the Founder's poly/rod combo this spring, then a few weeks later put on the delrin roto joint.
The founder's rod is a QA1 piece, nice, but "loose" is how I'd describe it. It gives very good articulation for the rear axle. Noise is definitely up compared to poly.
The roto joint I had to "cut" an inch of thread to fit it in since the roto joints are inherently larger. They are quieter than the QA1 rods and since you can adjust, they are tighter and more absorbing of impact. It's been 5 months now of DD and they have not come loose. I put a bit of blue loc tite on the locking bolt for the joint.
