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Removing / Replacing cartridge bearings in Rear Wheels, by Trikebldr

This how-to is aimed primarily at the Shimano-made cartridge-bearing rear hubs used in the majority of Catrikes for the last several years. Speeds, Expeditions and 700’s used the Shimano “Deore” branded hubs mostly, and those have cup/cone hubs, making their bearings easily adjustable for play or preload. Roads, Trails and Pockets used primarily the “Catrike” branded hubs that had cartridge bearings in them. There are many exceptions to which hubs were used in all of the models, but this is what will be found in the majority of cases. Other brands of cartridge-bearing hubs may be the same. 
Replacing the bearings in a rear wheel hub that uses cartridge bearings is pretty easy, but not without pitfalls. If done correctly using the right tools, it should only take about five minutes.
Almost all of Catrike’s hubs, either cup/cone or cartridge, came with rubber conical boots over the ends of the axles. These are critical on cup/cone bearings because they keep the dirt out of the bearings. However, they are not necessary on cartridge-bearing-hubs as the bearings have their own seals. For simplicity I have left the rubber covers out of any pics. I also do not run those covers on my own cartridge-bearing-hubs.
There are two problems that can complicate removal of the cartridge bearings. First, some of the 130mm wide hubs have the inner lock nut on the drive side (the side where the cassette is) recessed so far inside the freehub that you cannot get a wrench on it. The second problem is being sure to remove the washer that spaces the bearing from the axle’s shoulder on the non-drive side. I will address each one of these problems separately.
First, the picture below shows the inner lock nut so far inside the freehub that you cannot get even a thin cone wrench on it.
The above is on a 130mm wide hub. On a 135mm wide hub, the nut would not be quite so recessed.  A good, thin cone wrench can grab those flats on the 135mm hub, but on the 130mm hub, you must first back the inner lock nut off just a bit on the non-drive side (picture below), ….
…then, using a rubber or plastic-faced hammer, or a press (for ceramic bearings), drive the axle toward the drive side enough to expose the inner lock nut (picture below) so it can be loosened.
This is how to remove the drive side lock nuts first. It is recommended to use a good quality cone wrench (By Park Tools or Pedro’s, for examples) on the inner lock nuts because they are properly hardened to take the abuse of such a thin wrench being used to loosen and tighten these nuts.
Some of you may say, “Well, just remove the non-drive side nuts completely first and drive the axle out toward the drive side.”. This brings us to the second problem. There is a small washer between the non-drive side bearing and a shoulder machined on the axle. The picture below shows the whole assembly laid out as it assembles, with the non-drive side to the right in the picture.
There is no washer on the drive side. The Picture below shows this washer on the non-drive side, and the next picture below hows no washer on the drive side. This washer MUST be kept oriented exactly as it is from the factory!
Non drive side with washer
Drive side with no washer.
The two pictures below show that the washer is not symetrical. One side is convex and one side is flat. The convex side also has a small radius on it’s inner edge that matches the radius next to the shoulder on the axle (picture 10). If it gets flipped over during reassembly it will cause serious problems. Mostly, it will space the bearings farther apart, and this means the bearings’ outer race edges will no longer seat properly against the hub body’s bearing pockets. Under load, the bearings will “walk” side-to-side, slowly wearing the pockets larger until the bearings will be sloppy inside the pockets.
The next pictures show the groove for the washer, the washer assembled correctly on the axle, and a cross section of the axle and the washer, with exaggerated curvature of the washer. 
The picture above show the distance between the bearings being 3.224″, which is correct for this hub, axle, and bearing assembly.
The pictures below show the washer and axle assembled with the washer reversed, showing a distance between bearings of 3.236″. For precision bearings, this a big difference.
It should be apparent to the reader that this washer MUST be kept oriented correctly during reassembly. The problem is that if you remove the non-drive side lock nuts first and drive the axle out toward the drive side, that washer will then be floating inside the hub body and can be flipped around freely. It is important to keep the axle, washer, bearing and inner lock nut together until the axle is removed and the washer is examined for correct orientation.
Again, the reader may ask, “Why not just place it with the convex side away from the bearing all the time, then?”. Because sometimes Shimano flips these washers themselves to obtain a correct spacing between the bearings to suit the hub body they will be going into. Both the axle and the hub body have tolerances that are kept within limits during manufacture, but the axles and bodies still have to be matched somehow, and these spacers (washers) are how they make everything fit correctly. Hence, we run into another small problem. Hub bodies, axles and washers must be kept as a “set” to be sure of a correct fit for the bearings, and that washer must be installed the same every time! If the washer is replaced with one that is thinner, you could actually put so much preload on the bearing to burn it out shortly. Ceramic bearings have been crushed from too much preloading due to replacing that washer with a thinner one!
Once the non-drive side bearing, washer and lock nuts are removed from the axle, the axle can be used to drive the drive-side bearing out of it’s seating.
Once the bearings are removed, if you want you can pop the coverings, clean out the old grease, put in new grease and reinstall the old bearings. We have experience with relubing ceramic bearings in this way with no ill effects, through at least 3 relubes.  See how to do the relubing step in this article.  
On reassembly, it is easiest to start by assembling the drive side. Slide the bearing onto the axle, then put the inner lock nut on. Using both lock nuts on the non-drive side, tighten them together for use to hold the axle still while you tighten the inner lock nut on the drive side against the bearing. Then, tighten the outer lock nut against the inner lock nut. The drive side is done. Take both non-drive side lock nuts off the axle. Insert the axle from the drive side. It should now look like the picture below on the drive side, and the second picture below is how the non-drive side should look.
Drive side of hub
Non drive side of hub.
No need to drive the bearing into it’s pocket at this time. It will slowly be pressed it in as we tighten the inner lock nut on the non-drive side. Now, install the washer (picture below) the bearing (second picture below), and the inner lock nut (third picture below).
Using this lock nut, and a wrench on the outer lock nut of the drive side, tighten this inner nut (picture 18) to draw both bearings into their pockets until this nut is tight against the bearing. Now install the spacer (picture below) and outer lock nut (second picture below) and tighten everything on the non-drive side.
Be sure that the amount of axle threads showing is even from one side to the other, and that neither side extends outside of the dropouts of the trike/bike. On cartridge bearing axles, the shoulders that the bearings ride against will almost always keep this axle protrusion correct if the correct bearings, original nuts and spacers are used.

Removing a Bicycle Cassette, by trikebldr

To remove a “current generation” of Shimano’s Hyperglide cassette from the freehub of a rear wheel you will need two rather specialized tools besides a 12″ adjustable wrench. First, the lock-ring that holds the cassette on the freehub has 12 internal splines, as can be seen in the first picture.

Park Tool’s #FR-1 or #FR-5G will fit this lock-ring. FR-5G has an alignment pin that makes the job of loosening the lock-ring a lot easier. Without the pin, the tool is hard to hold in place while also holding the cassette with a chain-whip. Using a quick release skewer lightly snugged up will also hold the tool in place. In the second picture you can see FR-1 on the left and FR-5G on the right. The third picture shows FR-5G in place for loosening the lock-ring.
The next tool you will need is some kind of device to hold the cassette from rotating backwards (counter-clockwise) as you loosen the lock-ring. Large ChannelLock-type pliers will not do it as they tend to bend or nick the teeth of the cogs of the cassette. An old piece of chain used with a pair of Vice-Grips will hold the cassette well enough for loosening. The best way to hold the cassette, however, is to use Park Tool’s SR-1 chain-whip, or equivalent, positioned as seen in picture four, to the left.
A 12″ adjustable wrench, a 1″ open-end or box wrench, or even a 26mm open-end or box wrench will turn the FR-5G tool to loosen the lock-ring, as seen in the fourth picture.
Holding the chain-whip, turn the adjustable wrench counter-clockwise to loosen the lock-ring. The lock-ring and the smallest cog of the cassette have serrations on their mating faces to help prevent loosening while riding, so you will hear some clicking as you loosen the ring. Once it is loose, remove the chain-whip and wrench and also the ring. It should look like picture five.
Now, simply lift the cassette off of the freehub, but be careful to hold onto the two smallest cogs of the cassette because they will not be firmly attached as the rest may be. Take special care to notice how they fit onto the cassette for replacement later. Notice how their flanges face, and how they also have a larger spline tooth and smaller groove like the rest of the cogs on the cassette. These must all line up.
Most cassettes are held together by a single screw that keeps all but the two smallest cogs together for easier handling and assembly. Some cassettes have all but those two smallest cogs rivetted to an aluminum spider, too! But, some cassettes have all of their cogs and spacers simply assembled onto the freehub’s splines one-at-a-time. Be very careful about keeping everything in order and be sure you know exactly how all of the spacers and cogs fit onto the freehub. Each spacer has two small pins that MUST fit into the correct holes of the cogs. If they don’t, they will hold two cogs just slightly too far apart and that will ruin the alignment that allows for index shifting. If you are not absolutely sure you know how all of the spacers and cogs fit together, then if they all feel loose as you try to lift the cassette off the freehub, stop and take it all to your local bike shop for servicing.
The freehub with the cassette removed should now look like picture six.
The majority of freehubs are made from hardened steel. Some road freehubs were made with aluminum spline shells to help save weight. Once the cassette is finally removed, these softer splines will usually show where the cogs have dug into the edge of the spline over time and under heavy loading. It will also make it hard to remove the cassette on these freehubs.
To replace the cassette on the freehub, just line up the large spline tooth of the cogs with the large spline groove in the hub’s shell and slide the cassette onto the hub. Be careful to get the flange of each of the last two cogs facing the wheel. Screw the lockring on and tighten it with the special tool and wrench. It doesn’t need to be “stand-on-it” tight. Park Tools lists it as needing about 260-434 in/lb. (about 21.7-36.2 ft/lb). Since the freehub’s ratchet will stop the cassette from turning clockwise as you tighten the lock-ring, you do not need the chain-whip for installation of the cassette.