Jomurema Ceramic pressure plates

Jomurema was kind enough to send me two sets of their new product for testing.
Ceramic pressure plates for 2WD ball diffs.
Big thanks to Johannes at KB-M.

Reducing rotating mass have always been important, but this has not always been so easy to do with the parts available.

Reflex Racing was early on with their Lightweight spurs, and this sparked the interest of a lot of other manufacturers out there to do something about this.
PN came out with their superb alu lightweight shaft, and  QteQ have the insanely good and light diff housings and hub.

Various manufacturers has recently released prebuildt lightweight ball diffs, and these are actually very good products.
But for the ultimate lightweight diff you have to combine a few parts from different manufacturers.

Now onto the review.


The ceramic plates arrived in a small plastic bag. 
White in color, they look trick, and the dirt buildup is very easy to spot. Nice!
No sanding necessary, since they are super flat.

I was a bit worried about the fitment, since ceramic are next until impossible to modify without breaking it. I took a pair of QteQ diff housings to testfit, and they were a direct fit. Kyosho housing was also a direct fit. 
I have been told that D cut plates also will be available for Atomic and PN diffs.


 Measurements Jomurema:
- Thickness: 0,83mm 
- Outer diameter: 15,14mm
- Inner diameter: 8,20mm
- Weight pr plate: 0,3 grams


Measurements Kyosho original:

- Thickness: 0,83mm 

- Outer diameter: 15,33mm

- Inner diameter: 8,20mm

- Weight pr plate: 0,8 grams

Mounting is easy.

Remember to glue the pressure plates to the diff housings. 

I used ceramic balls in my build, but I am not sure if this is the best for these plates.

The feeling of the diff changed a bit, especially if you run some slip in your differential. I guess this is because of ceramic against ceramic. The wear does look to be zero.

I have a feeling that the grease will be very important in diffs built like this. You can change the way the diff "grips" quite a lot with different grease, so do not be afraid to try different manufacturers ball diff grease.

I have always used Kyosho and RC246 ball diff grease in my diffs. This is a grease that contains some kind of filler to grip better.

The action of the diff are extremely smooth. I had to adjust the tension a bit harder than I am used to to get the action to be the same as before. The good part is that it is possible to get the feeling to be almost exactly as with regular pressure plates.

The total weight of my diff is now as stated 4,0 grams. This is insane.

Acceleration and deceleration are improved. I guess this will be very popular in stock class, but also in modified if you like lots of drag brake and the added response.

I am going to try these plates with steel balls also to see if I can spot a difference. This could also affect the wearing rate. 

After roughly 3 hours runtime, mine has started to show signs of a groove. (More of a polished look really) It looks to be as other plates regarding wear. Only time will tell if they are better or worse.

All in all. If you are trying to build the lightest diff out there, these plates are a must. I love them already :D

This is my part list for my (for now) ultimate differential:

QteQ Ultra light weight differential housing set. QT-081101
QteQ Light weight differential left hub. QT-080801
Reflex Racing 64 pitch Machined spur. RX1154
Reflex Racing High grade diff center bearing. RX1157Reflex Racing High grade ceramic thrust bearing. RX1137
Reflex Racing ceramic differential balls. RX1119
Jomurema Carbon diff shaft. JOM280001
Jomurema Ceramic Pressure plates. JOM280002(Prototype parts)