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The First Tadpole Tricycle

The first tricycle that I have found with the two wheels in front and the larger wheel in back (the tadpole configuration) was patented in England before 1876, and sold as by the Rudge company.   The seat was like a carriage seat, with coil springs to absorb shocks. The large rear wheel was the drive wheel, and the front wheels were for steering.  This model is propelled by levers and cranks, but this mode was later replaced by the chain and crank.  Between 1880 and 1890, this form of bike was one of the most popular cycles in England, being even more popular than two wheelers.


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

The Spring Seat Post

One way to provide some suspension to a bike is to have a seat post with a spring or other shock absorber in it.  Joseph Smith patented one such device in 1899. 


Bruce’s Complete List of Bike Tools

Below is a list of the tools that trikebldr used when stripping and assembling a Catrike with Lucinda C. (Pink Panther) .

Says Bruce: Some are listed as the set they are a part of. I’m a big fan of Park’s line of tools, but you can substitute for a lot of them. With this list, you can tear a current model Catrike completely apart.

Park Tools list (with Park parts numbers)

Polylube 1000 (PPL-1)
Antisieze compound (ASC-1)
Master link pliers (MLP-1)
Allen wrench, folding set (AWS-11)
Cable and housing cutter (CN-10)
Pedal wrench (PW-3)
Chain whip (SR-1)
Bottom bracket cup wrench (BBT-9)
Crank removal tool (CCW-5)
Crank extractor (CWP-6)
Cassette lockring removal tool (FR-5G)
Bottom bracket retainer tool (BBT-32)
Chain breaker (CT-3)
Spoke wrenches
Adjustable spoke wrench (SW-10)
Wheel truing stand (TS-2)
Wheel dishing guage (WAG-4)
Cone wrench set (SCW-13 through SCW-18)
Repair stand (PCS-9)

All other tools

Calibro (from Catrike)
3-in-1 oil
Tri-Flow lubricant
FinishLine KryTech Wax Lubricant
Rubber mallet
Ball-peen hammer
Allen wrench set, metric, 1.5mm-10mm, ball-end type
Allen wrench set, SAE, 1/16-3/8″, ball-end type
Crescent wrenches, 6″ and 12″
Channel-Lock pliers, 6″
Needle–nosed pliers
Side cutters, (!+%*%)
Torx wrench, T-25
Ratt-tail file, 3/16″ or 1/4″
Small mill file, 8″
1/4″ drive torque wrench, 0-100 in/lb
1/4″ drive allen bit set, metric
Tire spoons
Tire pump

NOTES- Of course, a lot of these can be substituted for according to personal preference. The lubes are a personal choice. The wheel truing stand and dishing guage are Park’s best and can be substituted for much cheaper. Park makes a new hammer (HMR-2) with a replaceable rubber face on one end and a steel face on the other. It’s very nice and at $10.95 a pretty good deal. Both allen wrench sets are available at Lowe’s as HUSKY brand as one set (about $20). The side cutters are for crimping the cable-end ferrules, and for cutting the excess cable tie ends.

The multi screwdriver I use is a Cobalt brand from Lowe’s. They have several different styles and sizes. Cobalt are good tools, and they go along quite well with all of the Park blue tools!!! The files are for when you drive the axles out with something a little too hard and kick up a burr that won’t let it go back in! I also use a 3/8″ drive torque wrench on some things because Park’s 1/4″ TW only goes to 60 in/lbs.

The repair stand is a personal choice, but I looked at many, and tried fitting my Speed into them, and only the clamping head on the PCS-9 would fit a Catrike frame at the point where it gives a good balance so you can spin the trike to any angle you want for work. Lucinda already had a different stand, but she found out the hard way the same thing I found. I bought the cone wrenches as a set, but we only used the 15mm during the teardown of a rear wheel hub.

Spoke wrenches are also a personal choice. Pedro’s makes a great set, as well as Park. I have found that I use two different sizes on one wheel at times because nipples are often not very consistent in dimension. I just make sure that the wrench fits very tight on the nipple. If one gets rounded, then you will need the adjustable wrench to work it. The adjustable spoke wrench is about $32, but well worth it the first time a nipple rounds off! Park’s four-sided spoke wrenches are better yet. They grip the spoke at all four corners of the nipple to help keep it from slipping. I believe that Pedro’s makes these, too.

Needle-nosed pliers will do the same job as the master link pliers. Lucinda and I never did tear apart the freewheel (don’t confuse this with the cassette!) on the rear hub, nor did we remove it from the hub. Most books say that it takes a 10mm allen wrench to remove the freewheel from the hub, BUT, I found in all five Cats that I have around here that it takes a 7/16″ allen to fit. Maybe Rick (recycledteen) will chime in here to verify what he used to remove his a while back?!?!?! BTW, 7/16″ allens aren’t EASY to come by! The special “socket wrench” that it takes to open up a freewheel can vary, so you need to check with your local bike store to find out which one you need. Most shops don’t mess with them. They just replace the whole freewheel assembly. About the only reason to open one up is to clean out the heavier grease and put in a lighter grease, or use oil in an effort to reduce rolling friction during coasting. It DOES make a difference. If anybody NEEDS to know which tool it takes for Cats, I can look up which one I use.

One last tool I have and use that I would like to mention for you serious wrenches, but didn’t break out while Lucinda was here, is my bottom bracket threading/facing tool. It’s a Park BTS-1, and it ain’t cheap! If you only have one or two trikes/bikes to maintain, just have your lbs do the job. They usually charge about $55 to do the thread chasing and shell facing job, so if you have it done nine times, you’ve paid for the tool!

Of course, good friends, good music and good food go a long way to making the job go better! You’re on your own there, though!

Bruce (trikebldr)