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Ceramic Bearings for Catrike Front Hubs

Bruce on ceramic bearings: I’ve replaced the stock Catrike bearings with ceramics bearings on both of my Speeds. Front and rear. In a year and a half I’ve burned up two of the stock bearings, so I was looking for something that is more durable and that I wouldn’t have to worry about again. It just so happens that they really improve the coasting abilities of a trike, which also means they reduce pedaling effort. But, they ain’t cheap! PRH has just done the ceramic swap in the rear of his trike, and is awaiting the arrival of his new fronts. He felt the improvement from just the rears. If I recall, they are about $50/bearing, and there are four of them in the two front hubs. It takes about ten minutes to replace them in each front hub. Here’s a link to my section on Flickr where I keep my pix of the guts of a front hub, showing the bearings and how they fit. For information on how to remove these bearings, check out this post. It’s easy!

Click here to see pix of a front hub disassymbled.

ABEC stands for Annular Bearing Engineers’ Committee. This committee works to determine the standards for bearings for the Anti-Friction Bearing Manufacturers Association (AFBMA).

The ABEC scale classifies different accuracy and tolerance ranges for bearings. The first column of this table lists the five ratings in the ABEC scale.

ABEC Ratings ISO Class

ABEC1 Class 0
ABEC3 Class 6
ABEC5 Class 5
ABEC7 Class 4
ABEC9 Class 2

The ABEC rating of a bearing is determined by the following (for a 608 size bearing):

1. How close the bore is to 8mm in microns
2. How close the outer diameter is to 22 in microns
3. How close the width is to 7mm in microns
4. The rotating accuracy in microns


Thanks to PRH for this latest info on these bearings! These are the bearing and part numbers to order them from VXB Bearings. You will note that these are also ABEC-7 bearings, as well as ceramics.

Kit8041 6904-2RS Bearing 20x37x9 Si3N4 Ceramic:Stainless:Sealed:ABEC-7 Quantity 2

same bearing from BOCA Bearings

Kit7660 6805-2RS Bearing 25x37x7 Si3N4 Ceramic:Stainless:Sealed:ABEC-7 Quantity 2

same bearing from BOCA Bearings

Each front wheel uses one 25x37x7 bearing, and one 20x37x9 bearing, so you need two kits, each with 2 bearings, for a total of 4 bearings for the two wheels.


For standard Catrike rear hubs you need one of each of these kits from

Kit7653     6000-2RS Bearing 10x26x8 Si3N4 Ceramic:Stainless:Sealed:ABEC-7 (about $30)
Kit8160      6200-2RS Bearing 10x30x9 Si3N4 Ceramic:Stainless:Sealed:Nylon:ABEC-7 (about $33)

I believe that all current Catrikes use the same hubs and bearings. The older front hubs used two of the 6904 bearings, but all of the current models use one each of the above bearings in each hub.

An excellent step up from the stock bearings on a Catrike would be to good stainless steel bearings. The next step would be to stainless ABEC-7 bearings. The next step would be to non-rated ceramics. The top of the line (well, almost!) would be ABEC-7 ceramics. You will note that “Stainless” is listed in the description. That’s because the globes (balls) are the ceramic component, but the races are stainless steel.

The best analogy I can give of the difference in ceramic versus steel balls is the difference between a golf ball and a ping-pong ball, as far as smoothness.

Unless you just have a bunch of money to spend, I would recommend running the stock bearings until one of them gives you trouble, then replace them all with ceramics, keeping the stock ones for spares.

Concerning sealed bearings, they can be lubed. That process is discussed in a separate post located here.

My experience (Bob’s) with ceramics has been that they make a 2-3 mph difference in my riding. I found a roll out hill with a straightaway below it, and I coasted my trike on the test track before and after installing ceramic front bearings. Over about a 300 yard run, the trike went 40 paces (120 feet) further with the ceramics. On all the “go fast” sections of my regular route to work, over the next week I set new personal best times on every section, by about 3 mph. On one section, the new speed ability made me try to complete a 6 block section at speeds above 20 mph. I was successful at that. My usual speed over that route is more like 17, and on some areas I usually drop down to 13 or so.

Bruce says the bearings will get better after 200 miles of run in, so I’ll retest them later.

If you install ceramics looking for speed, you should remove the seals, clean out the grease they come with, add replacement grease, and replace the seals. Excess grease would be displaced by the bearings as they rotate, and would come to rest on the bearing cage. During use, oil from the grease would seep out and lubricate the bearings. But if there is so much grease that the bearings have to continually push it aside you will lose any speed advantage the ceramic bearings might have given you. When you replace the grease, you can also make a batch of “thin” grease to pack the bearings with, made of 70% grease and 30% 3-in-1 oil. The picture below shows how much “thin” grease I added.


Replacing the Rear Wheel Bearings on a Catrike

13 comments to Ceramic Bearings for Catrike Front Hubs

  • Thanks for the very interesting article!

  • Mike Armstrong

    Good article; now I just need to wait for my bearings to fail. The Flickr link ( is broke, according to Flickr — looks like a typo; hovering over the link gets a popup of “Full text of United States Patent Application Publication No. 04341445700”, and the HTML in that area is really weird. Might have something to do with the “.

  • jim

    have a question, are ceramic bearings sold as loose balls so i can rebuild my bicycle hubs ?

  • The ones I got were in a retaining ring. I don’t know if loose ceramics are available or would work as well. Bob

  • Jim, sorry I didn’t see your post earlier! YES, ceramic globes (Balls) are available separately to rebuild what we refer to as cup/cone bearings found in a lot if bike hubs. You first have to determine what size your old ones are, then go to the VXB Bearing site and look them up. They are generally sold in bags of ten, and cost about $2/each.

  • I have found that has these bearings much cheaper than VXB or Boca Bearing.

  • Pookers

    Hello, I own the Catrike 700.
    However I ordered it special with 20 inch front wheels.(Catrike stock wheels)
    Can you tell me what size of bearings to buy for the front hubs?
    Thank you

  • I’ll ask if Bruce knows, or knows where to find out. Off hand, I’d call Catrike and ask Mark, or the guys at Utah Trike, or Mark Powers at Power on Cycling.

  • You might just have to pop them out and measure them. Bob

  • Denman

    Boca Bearings rating is ABEC1 with a cost of $143 for a front end set.

    VXB ratings are ABEC 5 with a cost of $181 for front end set.

    It sounds like the comparisons above are with VXB, but its not stated.

    I need to replace a set of Catrike bearings but not sure which way to go.

    VXB steels are given a “motor” grade; thats practically useless since motor grade deals with resistance to arcing between the beraing hub and the armature. Other then that I don’t see any high grade steel bearings.

    Anyone care to chime in over brands?

  • Pookers

    One other thing, you list TWO kits?
    Kit8041 6904-2RS Bearing 20x37x9 Si3N4 Ceramic:Stainless:Sealed:ABEC-7 Quantity 2

    Kit7660 6805-2RS Bearing 25x37x7 Si3N4 Ceramic:Stainless:Sealed:ABEC-7 Quantity 2

    Which one is it?

  • Each wheel uses 2 bearings, a 20 x 37 x 9, and a 25 x 37 x 7. Each “kit” has two bearings of the same size. You need 2 kits to get the 4 bearings you need for two wheels.

  • Pookers

    Good to know,……….thanks

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