Why Spherical?

Ive been running a *fully* spherical setup on my personal E92 M3 for over a year as a writing this. Ive put a handful of trackways and around 20,000 miles during this period. So I have been running it long enough to formulate an opinion.

A Spherical (also known as RoseJoint) is an alternate solution to factory rubber arm bushings on cars. Spherical bushings are a "direct" way to mount your hubs to the chassis.  Eliminating all play from the rubber bushings it greatly improves the feel of the car by making it much more direct. Coming from race cars, road cars were soon to pick up the benefits of Solid mounted cars.

CMP's bushings work especially well on lowered cars since they were designed with them in mind. Lowering a car brings your geometry specs out of what's ideal. By raising the while subframe, CMP fixed this issue and added great benefits on top of that: in the form of Bump steer, Roll center, Anti-Dive, and Anti-Squat correction. This can be found in both the Subframe bushings and Front Control arm spacers.

With my car being 70,000 miles old, the bushings had quite some play, which I noticed and disliked. My solution was spherical! The first thing immediately noticed was how fresh the car felt loading up. It felt more supportive going into and during corners. Which is thanks to the Geometry correction kit from CMP which can be found on our site. The whole car just felt "right."- Not like it's modded. It makes our cars perfect in my opinion. A spherical setup with supporting mods has great potential to put you on pace with GT3's :)

After running spherical for so long, in nearly every situation (highway, traffic, North East roads, Track, In the snow) I can only recommend them! The car immediately felt more planted, but still not any more uncomfortable. With the fully package, I did notice some small noises can be noticed at low speeds like coming out of your driveway. But nothing that makes me dislike it. 

The biggest thing was how much more quality the car felt, as I said before the car just felt how I envisioned the ideal E9X to be. But it still felt like a comfortable GT car, after all it is an M3! 

Rear end play On-Throttle (Toe arm, Camber arm bushing, Subframe bushings):

One of the more noticeable improvements was the stability of the rear end, especially during on throttle pulls. Before (and as you guys might feel), the rear end had a bit of play, or "waggled" under acceleration- You could feel the rear end flex and move under power. This was due to the Toe arm and its subsequent bushing deflecting under load. it gets rid of all unwanted bushing flex to keep your Geometry more consistent while to car is experiencing loads. This is the reason we so highly recommend the CMP Adjustable toe arm, it filters out that unwanted flex (and therefore movement) in the rear end. Since toe = steering.

Shortly after I added CMP's Rear Subframe bushings with Geometry correction which further aided this issue. I also fished it off with CMP Rear camber/guide arm, Spherical trailing arm bushings, and a Spherical Lower camber arm inner bushing Eliminating all play on the rear end.

*It's important to note that I am running Eccentric lockouts, which I highly recommend. It eliminates the possibility of your Eccentric lockout moving and causing your alignment specs to go out.

Front end turning and Braking (Thrust arm Bushing):

The next thing id like to cover is the Spherical (and sealed) front thrust arm bushing, also Supplied by CMP. This mod adds no negatives over stock: No additional maintenance and No NVH. Due to its position in the thrust arm, nearly all steering inputs and forces are sent though this point. The stock bushing is quite soft, so there's a decent bit of play which most people can notice, especially under braking and higher speeds. The replacement of this bushing completes the front end as a fully spherical setup, using an OEM Ball joint. Since the other positions are spherical from factory off the front subframe, this completes it. We also get a fair bit of bump steer running the stock brushing here. Using a Spherical FTA along with CMP's bump steer spacers on my lower control arms completely eliminated the bump steer from my car. And because of this we recommend this part on every single car, no matter what its use is.

Spherical FTA's also eliminate the 80mph wheel wiggle our cars get!

Track day review:

After driving for a few weeks on the street with the setup I ran my first track day with it, and boy did it make a world of differences. The whole car was easier to drive, thanks to having nearly no play in the car. Braking was also improved, the front end no longer moved under heavy braking, as before there was slight movements sent up through my steering wheel in heavy braking zones. Now, the car was totally settled during heavy braking zones (154-40mph). The added Anti-Dive from the CMP Spacers was also very noticeable. The front end was very supportive during braking.

Something I didn't notice before was the "issue" with corner entry and mid corner. On a stock car it felt like the car took forever to settle, and when It was settled it still felt unstable mid corner. Compared to running the spherical setup there was never any thought about the car not settling fast enough, or settling in a way I didn't want. Every time it felt as good as I ever would've thought. Incredibly easy to drive at great pace too. Couldn't recommend it more!

Curbing also was a piece of cake running CMP's Geometry and bump steer correction, the car no longer got unsettled/unstable and took it like a race car! 


  1. CMP's Front Thrust arm bushing
  2. CMP's Spherical Rear toe arm with Lockout
  3. CMP's Rear Subframe bushings with Lower arm spacers
  4. CMP's Rear lower inner camber arm bushing
  5. CMP's Adjustable Camber/Guide arm 
  6. Meyle Spherical trading arm bushing



Back to blog