In this article I will review the C-Bear OCM Ceramic Pulley Wheels for Shimano GRX-RD-820 12-speed rear derailleur on the Canyon Grizl CF SL 8 1-by. On the Canyon Ultimate CF SLX I’m also running a pair of ceramic pulley wheels.
TABLE OF CONTENTS
Key Features C-Bear OCM Ceramic Pulley Wheels
Before looking into the key features I would like to explain what C-Bear OCM is all about !? On the OCM pulley wheel overview page you can read:
C-Bear OCM (Original Cage Optimized Max) pulley wheels, fits original cages of Shimano. No extra purchase of an additional larger size cage #smartspending
Each C-Bear pulley wheel set consist of 2 wheels, upper and lower with ceramic bearings of your choice:
1. hybrid ceramic bearings or
2. full ceramic bearings – least friction option
Original Cage Optimized Max, simply means two different sized pulley wheels (13 tooth for the lower pulley wheel, 12 tooth for the upper pulley wheel), that are bigger than the stock ones and optimized for the biggest as possible within the constraints of a standard derailleur cage. Good quality pulley wheels will save some watts, and C-Bear is substantially cheaper that the Ceramicspeed Oversized Pulley Wheel Systems you sometimes see world tour professionals riding.
On my Canyon Ultimate CF SLX 8 Road bike I’m using CEMA Bearing Full Ceramic Pulley Wheels, but on a gravel bike with a lot of exposure to dirt and dust, the full ceramic bearing option doesn’t justify the additional investment. Using the hybrid ceramic bearing option is also the advice provided by the C-Bear team. Great service pre- and post sales.
The aluminum C-Bear OCM ceramic pulley wheels have an open design, which is key for keep your chain run smoothly even in the muddiest conditions. Mud doesn’t clogg up easily, and the open design has huge advantage of easy cleaning with a piece of cloth. The combination of aluminum and open design also saves some weight on your bike. The Aurora versions of the C-Bear OCM ceramic pulley wheels have a closed design (for both road and gravel).
Another key feature of the C-Bear OCM pulley wheels is the availability for a wide spectrum of group sets (road and off-road):
- Shimano 105 (11 and 12 speed)
- Shimano Dura Ace (11 and 12 speed)
- Shimano Ultegra (11 and 12 speed)
- Shimano GRX (11 and 12 speed)
- SRAM Eagle
- SRAM Eagle Transmission
The stock pulley wheels from Shimano are of a similar size (and tooth count), have different bearings, no open design and thus not optimized.
Installation C-Bear OCM Ceramic Pulley Wheels
The installation is the easiest with a de-installed Shimano GRX-RD-820 rear derailleur, because it means you’ve broken the chain and can easily work on the rear derailleur on a workbench (without any cable or chain tension). However I’ve installed these without removing the rear derailleur, only taking the wheel out to properly work on the upper pulley wheel.
- I would go for a like-for-like replacement approach (replacing one pulley wheel after the other);
- You simply untighten the bolt for the pulley wheel and remove the bolt. The Gear Mech Plate is still in place with 1 bolt (that advantage of like for like) and see also Fibre Lyte Gear Mech Plate Shimano Dura Ace 9000
- Remove the stock Shimano GRX pulley wheel from the rear derailleur;
- Slide in the C-Bear OCM ceramic pulley wheel into the rear derailleur, and put back the bolt. Tighten it to dealer manual specification (2.5 – 3.0 Nm);
- Check if the rotation markers on the pulley wheels are correct, or in the case of the different sized C-Bear OCM ceramic pulley wheels, make sure you have them in the correct position (big and small);
- Repeat the steps above for the other C-Bear OCM ceramic pulley wheel;
The average home mechanic should be able to get this done easily, and also when the Shimano GRX-RD-820 rear derailleur is not de-installed. It will take you less than 15 minutes and after installation no adjustments are needed.
And when needed Shimano has some good technical documentation, manuals and exploded views available for the Shimano GRX RX-820 group-set.
Concluding thoughts and wrap-up
The C-Bear Ceramic Bottom Bracket for BB86/BB92 is one of the best investments I’ve done on the Canyon Ultimate CF SLX 8 road bike. Superb value for money and from such a high quality that it is lasting very long (> +/- 30.000 km) without any special maintenance. Given this experience, I wanted to give the C-Bear OCM pulley wheels with hybrid ceramic bearings a try in an off-road gravel set-up.
The price point for the C-Bear OCM Shimano GRX 820 ceramic pulley wheels is € 120,- which is not cheap. Given the experience and quality this is a fair price, especially if you compare it against Ceramicspeed ceramic pulley wheels. But time will tell how long these will last.
Installation will take you less than 15 minutes, and from initial installation you probably never ever have to look after the pulley wheels again for many kilometers and years (just the regular maintenance).
What is also important to me is the communication, advice and service that I gained from the C-Bear team, before I made my purchase. I’ve read mixed user feedback about the Token Ninja BB4124PS Bottom Bracket so I’ve ordered another C-Bear Bottom Bracket for my Canyon Grizl CF SL8, the All Conditions version with additional protection.
- Do you anything other than the stock Shimano pulley wheels ?
- If so which brand pulley wheels did you install ?
- What is the maximum price-point that you are willing to pay for pulley wheels?
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Unfortunately I’ve gathered my own experience with Token Ninja BB4124PS Bottom Bracket. Not surprisingly it is removed, given the quality and wear it puts on the 24 mm Shimano crank-spindle.
Removing the plastic interlock cups of the Token Ninja BB4124PS Bottom Bracket is something that needs to be done with care (or you risk damaging your frame). The edges of the cup also get sharp, so please wear some mechanic gloves.
I’ve ordered and installed the C-Bear Bottom Bracket PF41-AC for my Canyon Grizl CF SL8, the All Conditions version with additional protection.