Maintenance Tips Bearings
Bearings stuff up when they are dirty, left to run dry or rust. So to keep them in tip top shape, give them a longer life and keep the speed up, we have a few basic rules for you to follow.
Rule #1 don't ride in the rain or through puddles. If you do, take them out immediately after your skate and clean them before rust sets in and it will set in fast. The rust will pit the balls and running surface (race) and they will be stuffed in a matter of hours. The rust flakes will also help to degrade the polished running surfaces of your rings and balls.
Rule #2 Oil your bearings regularly, using a very light/thin oil and wipe off any excess after oiling them. Oil acts as a magnet for dust and will soon clog your bearings, then the dust starts to grind away at your smooth running surfaces, it builds up and starts to push out on your shields. So after oiling them spin them a few times, wipe them and spin them again and wipe them again, do this quiet a few times before you put them back into your wheels.
If you don't look after your bearings at all they will dry out. This makes at first, bearings that seem to spin fast, but any grit from dirt etc will begin to grind away at their polished surface and they will quickly become noisy and slow down considerably. The surfaces do need to be lubricated every so often. Ceramics not so much but the bearing rings are still steel and will start to feel the wear.
The reason many skateboard bearings now come with only one shield is simply for easy cleaning. The side without a shield is kept to the inside of the wheel where no external dust can enter.
Cleaning
Ok... get yourself a small tray to wash your bearings in, some petrol, thinners or preferably some de greaser. Take your bearings out of the wheels, urethane doesn't like petroleum products.
NOTE: take care with your shields they are easily damaged and may not fit back on or they may rub against the balls and cage if they have been bent or dinted in. That's why I like the rubber shields, they are easily taken out and replaced, and also offer better water protection.
You'll need a pin to get your shields off. For rubber shields just poke the pin in near the outside edge and pull up, it should come out pretty easily. For steel shields, you'll need to find the end of the little cir clip around the inside of the outer ring. Poke your pin in and lever it out, the shield should then just fall off.
Soak your bearings in the de greaser solution for a while. Pick each one up and spin them a number of times. If they are caked in crap, you'll need to let them soak for a while or perhaps you could use an old toothbrush to help clean the crud off.
A word of warning here take note of any safety instructions for the solution you are using and don't get it in your eyes whilst spinning the bearings.
If you have bearings with a nylon cage they can be removed with a sharp point of some sort or a bamboo skewer, push them out from the side you can see the balls. Take care getting them out and putting them back in though.
Nylon cage removed
Once you are satisfied that they are clean and spinning free, dry them completely.
Find some good light grade oil. A thin synthetic oil would be best, it lasts longer and you don't need much at all. It also can withstand more heat before burning off, but how fast do you go? Some skate brands offer small tubes of lube, any of those should be good to use.
Apply a very small amount of oil (one or two drops) and spin, let it sit on a rag or paper cloth, and do each one in turn. Go back to the first one and wipe clean and dry with a rag, spin again and let sit again, do each one in turn again, until no more oil seeps out onto the paper cloth or rag and is totally dry on the outside. A very thin film over your bearings though will stop the surface from rusting.
Put back your shields, the rubber ones should just click into place the metals will need the cir clip popped back in. There you have it your done.
Push your bearings back into the wheel, taking extra care not to damage the shields. This is where a dedicated bearing tool will help. Make sure to use "speed washers" and "spacers". Speed washers give a slight gap in between your truck hanger on the inside and your axle nut on the outside. Spacers help to retain the two bearings as an integral unit, it spreads the sideways loads of skating between the two bearings and greatly reduce the chances of your bearings popping from either axial loads or over tightening your axle nuts putting pressure on the internal and external bearing rings.
Bearing set up showing speed washers and spacers.
