With the wheel removed from the trike, remove the six screws that hold the brake rotor on and set the brake rotor aside. Now, remove the black, stepped-spacer that slips onto the end of the bearing spacer tube. It is being held on by the o-ring inside, so it may be a little stubborn to slip off, but it will come off with just your fingers.
You are now looking at the side of the inner bearing, with the end of the bearing spacer sticking through it. With a leather or plastic mallet, gently tap on the protruding end of the bearing spacer tube until the outer bearing at the other end falls out. Push the bearing spacer tube the rest of the way out and turn it around to use to drive the inner bearing out. Just be very careful when tapping on this tube because the shoulders that the bearing inner races ride on is very critical to bearing placement within the hub. Maybe using a wooden dowel of the same diameter would be better to drive the inner bearing out. The inner bearing keeps the bearing spacer centered well enough to use it as a driver for the outer bearing. Now, your bearings are removed. The bearing spacer and the two bearings that go on either end of it, and the stepped spacer, are shown below assembled and disassembled.
At this point you can relube the old bearings, or install new ones. To relube the bearings, you remove the plastic seals, clean out the old grease with thinner, add new grease, snap the seals in place, and install the bearings. These pictures show those steps. Bruce says that someone who is trying for maximum speed out of a bearing, whether it is a ceramic of a steel bearing, should avoid putting too much grease in the bearing. Real speed seekers can even thin out their bearing grease with 3-in-1 oil, with oil forming 30% of the grease mix, and pack the bearing lightly with this “thin” grease.
To insert your new bearings, start with the outer bearing, insert it by hand and get it as squared up as possible before driving it all the way in. Slide the new inner bearing onto the protruding end of the bearing spacer and drive it all the way against the shoulder on the spacer. Now, insert that bearing into the hub on the brake rotor side. Using a 1/8″ pin-punch, SLOWLY drive it in, working around the outer race 1/8 circle at a time. Don’t use any kind of press, unless it is a precision press that drives absolutely flat against the bearing. If you get the bearing cocked even a little bit, it wll distort the hub’s recess for the bearing. Not good! Both bearings will be slightly recessed when they are fully seated, with the inner bearing being moreso.
Before starting this process, make very sure that the shoulder inside the hub for each bearing is absolutely clean. Again, this is very critical to the bearing’s location within the hub. Any dislocation of either bearing will cause a preload on both bearings when the wheel is back on the trike. This will create bind and make the trike pull to one side and cause premature bearing failure. Once the bearings are both back in the hub, slip the black, stepped-spacer back onto the bearing spacer tube protrution, making sure that the o-ring inside is in good shape. Now, put the brake rotor back on and you’re done!
When both bearings are inserted correctly, if you spin one bearing, the other should spin with it. The black, stepped-spacer shouldn’t rub on the brake rotor tabs. Once you get the old bearings out, do a thorough cleaning of the inside of the hub, especially inside the machined pockets where the bearings fit.
For more pics of the hub disassembly, refer to trikeblkr’s hub photo archive here.