DIY Project — Clean and Repack Bicycle Axle Bearings

This is another DIY feature on bicycle repair. We’re bullish on bicycles as an efficient and clean means of transportation. It isn’t as low tech as walking, but it is far better than any other mechanized mode of transportation, according to the discussion on a previous blog post. (cover image source).

We made a short video, which you can see here. Read on below for written instructions.

Low Tech Video – No. 2 – Repacking Bicycle Bearings from Low Technology Institute.

Remove the Wheel

I find it easier to remove the wheels when the bicycle is upside down (if you don’t have a bike stand). Flip the bike so it is resting on its seat and handlebars with the wheels up. Shift the rear gears down to the smallest gears (nearest the outside). This gives you slack in the chain and derailleur. Release the brakes. Some brakes have a lever that releases them, while others have to be pinched closed with your hands and the cable nub pulled free. Note how the brakes were released for later if this is your first time opening them up, since you’ll want to close them again later.

Now release the quick-release lever on one side of the axle (or use a wrench to loosen nuts if your bicycle doesn’t have quick release). Once open, spin the lever a few turns, until the wheel can be lifted free of the dropouts (small gaps in which the axles rest). For the rear wheel, you have to navigate the axles free of the chain.

810px-Labeled_Bicycle_Hub_Comparison-en.svg.png
A schematic of a bicycle hub (open source).

Remove the Axle

Over a pan with lips on your workbench or table, unscrew the quick release and pull the spindle out of the axle. Be sure to retain the springs and the oblong washers called lawyer’s lips (if equipped). Next to the hub, you’ll see the bearing cone, which looks like a nut from the outside. Use a narrow wrench (a bike-specific tool is called a “cone wrench”) to hold it while you use another wrench to open up the lock nut (refer to above diagram and video; locking nut goes counter clockwise while cone nut goes clockwise). If you don’t have a narrow enough wrench, you can use a wrench on the lock nut on the other end of the axle. When you turn them open (counter clockwise), one will open up and then you can continue the process from here. Once the lock nut is off, back the cone nut off the axle (counter clockwise again). You should now see the bearings between the axle and the hub. They might be held in a metal cage or they may be loose. In either case, carefully remove them with a needle nose pliars. If they are in the metal cages, you can lift the wheel up so the axle drops down and then pluck the bearings out. Be careful doing this if the bearings are loose, as the bottom ones will fall out and scatter (but you’re using a pan, so you’re fine, right?). Clean the bearings, cup, cone, and locking nut and then repeat for the other side.

Replacing the Axle

Put a bead of waterproof grease in the cups. I use Phil’s Waterproof grease because that is what my dad uses. Shop around, see what you like. If your bearings are in cages, set them down in the cup with the flat side of the cage up; the bearings should touch the cups. Screw the cone nut on one side of the axle until it is on about 1/2 in  (1.25 cm), lightly coat the axle and cone with waterproof grease, and then slide it into the axle so the cone contacts the bearings, not the metal cage. If your bearings are loose, assemble the cone and axle, slide it most of the way into the hub and then place the correct number (half of the bearings you have loose total, usually nine or ten) of bearings around the axle in the cup before lowing the cone and axle all the way down. Now turn the wheel over, keeping the axle in place so you don’t lose your bearings (ha!). Repeat the process on the second side: put a bead of grease in the cup, put the bearings in, grease the contact area of the cone nut and then rotate it down until it contacts the bearings.

At this point you should stand the wheel up and make sure the axle has equal amounts of thread showing on the left and right side. If not, loosen the cup nut with more axle on its side and then tighten the other side (careful not to open it up enough to drop out bearings). Tighten the cone nuts until you feel slight resistance. Put a locking nut on one side and tighten it down to the cone nut using your narrow wrench and other wrench (pull the cone nut counter clockwise and the locking nut clockwise). Flip the tire over. Now rotate the axle. Do you feel lugging, that is, do you feel a pulsing pressure as your turn the axle? If so, loosen the cone nut until it just stops. Can you push the axle laterally, that is, if you push or pull one cone nut towards or away from the other, does the whole axle move? If so, tighten the cone nut until it doesn’t move this way (but don’t over tighten and cause lugging). Once it is properly adjusted, tighten down the lock nut. Double check that the axle doesn’t lug or move laterally after the lock nut is tight. If either one is present, redo the last few steps.

Now lightly grease the cleaned quick release spindle. Load the spring on the spindle with the wide end towards the head with the quick release handle. If you have lawyer’s lips, add them here with the hook facing the hub, and then slide the spindle through the wheel (you’ll want the handle on the left-hand side as it is mounted on the bike, so check the direction of your tread). Slide the lawyer’s lips over the spindle with the hook facing the hub, then the spring with the small side towards the hub. Finally screw the hand nut onto the spindle threads.

Reinstall Wheels

Put the wheels back on in the reverse order from removal: slide the axles back into the dropouts and tighten down the quick-release levers; you’ve overtightened if you can’t push the lever back down flat. Reattach the brakes. I repeat, reattach the brakes. On the rear wheel, you’ll also have to be sure to thread the axle into the chain and then seat the chain on the outside cog before putting the axles in the dropouts.


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