This article is a short review of the CEMA Bearing Full Ceramic pulley wheels. I will try to compare these against stock Dura Ace 9000 pulley wheels, but I don’t have a friction facts laboratory setup at home. So it will be an in-depth look and feature comparison.
TABLE OF CONTENTS
FULL CERAMIC PULLEY WHEELS FROM CEMA BEARING
Pulley wheels from your rear derailleur are probably the fastest spinning bearings on your bike. So smooth spinning bearings for these pulley wheels make sense from a theoretical point of view.
A lot of professional World Tour teams have made the switch to pulley wheels with full ceramic bearings. For example Lotto Soudal uses C-Bear pulley wheels, while Team Dimension Data uses CeramicSpeed pulley wheels.
According to the wattshop article “Watts It Worth?” the switch to pulley wheels with full ceramic bearings will save about 1.5 – 2.4 watts. So the savings seem to be limited compared to the investment you need to make. However everything depends upon your budget. 🙂
So let’s have a look at the different versions …
Aluminum or Plastic Delrin Pulley Wheels ?
You can get full ceramic pulley wheels in two different materials:
- Aluminum
- Plastic / Delrin
Next to the pulley material you can select the bearing type: Full Ceramic, SRC ceramic or a stainless bearing. Of course has each bearing type its own price point from € 32,– for the stainless bearing up to € 95,– for the full ceramic version.
DURA ACE 9000 PULLEY WHEEL COMPARISON
Please check out the YouTube video here, that compares a standard Shimano Dura Ace 9000 rear derailleur pulley wheel with a CEMA Bearing full ceramic pulley wheel. While the video gives an idea of the spinning smoothness, it is better to feel it yourself. You can really feel the difference when you take a pulley wheels between the fingers and manually spin it.
The picture above shows the difference in bearing diameter and setup between the stock Dura Ace 9000 pulley wheels and the Delrin full ceramic CEMA Bearing pulley wheels. The diameter of the CEMA pulley wheels is larger, and the red cap makes sure the bearing are clamped correctly.
CONCLUDING THOUGHTS AND WRAP-UP
A little while ago I’ve reviewed the Bottom Bracket Replacement Tool from CEMA Bearing.
The switch to pulley wheels with full ceramic bearings will save about 1.5 – 2.4 watts, according to the wattshop article “Watts It Worth?“. However it are fast spinning bearings that need to run smoothly. So it will certainly give you a mental advantage in addition to some savings. Furthermore it simply looks cool and stealthy in combination with the Fibre Lyte Gear Mech Plate Shimano Dura Ace 9000. 🙂
The price-point of € 95,– for the full ceramic version of the CEMA Bearing Pulley Wheels is quite expensive, and it is up to your personal budget if you are willing to invest this amount of money for the savings and looks.
However I’m personally using these Full Ceramic Pulley Wheels from CEMA Bearing for the second season now … without any problems and still running smooth like butter.
Would you make the switch to full ceramic pulley wheels or not ?
Other CEMA Bearing product reviews on cycling-review.net:
Thanks Remo for the review. About 6 mo the ago I bought a 14T-12T full ceramic CEMA for my dura ace derailleur 9200. Last week during a deep cleaning I realised that none of the 2 wheels spun without end like when being brand new. I contacted CEMA and to my surprise they said to apply a degreaser (WD40) and wash it off after with a detergent. No need to apply any lube or grease after. To me that sounds dry and harsh and I have my reservations about it. Do you perform any regular service if your wheels? Thanks in advance
Hi Jorge,
I perform regular maintenance (weekly) of the complete drive train (chain, cassette, chainrings, derailleurs and jockey wheels). A clean drive train saves money (wear) and keeps shifting smooth.
So yes I put degreaser on chain with the Muc-Off X3 Dirty Chain Machine I use a sprayer to put the degreaser on cassette and derailleur.To get of any dirt or lube rests, I use the Finish Line Grunge Brush or the Dynamic Drivetrain detailing brush.
I haven’t dis-assembled the CEMA Bearing Pulley Wheels, or removed any of the seals. I would love to understand the reasoning of “not putting any lube or grease after”. I get that you cannot regrease with all products (viscosity and thickness), but not putting any protection would go against all my mechanical engineering foundation. But never to old to learn.
While the online video’s show a rotating pully wheel (or bottom bracket) without load on it, this is not the case with load.
Where do you live and how did you use the bike in the winter period ?
// Remo
I’ve received some feedback from the CEMA Bearing team. “Lubricating with a thin lubricant can be done, but is not required. It is not needed to lubricate.”
So I would use some PTFE teflon spray like:
– Dynamic Mechanics Magic
– CyclOn All Weather Spray
// Remo
Would you invest in full ceramic pulley wheels for your mountain bike or gravel bike ? In the off-road scenarios you will probably find more impact from mud, dust and water.
// Remo