To get the longest life and least friction from your hubs, you regularly must disassemble, clean, repack (grease) and readjust them.
Tools and materials
If possible, you should have `two special cone wrenches for each size needed to fit your hubs. This usually means two sets of cone wrenches. A set usually includes four sizes: 13, 14, 15 and 16 millimeter, and few cones are not covered by such a set. (Among the exceptions
To clean the parts you should have an old toothbrush, a supply of clean rags or paper towels and a good degreasing solvent. The degreaser is available in hardware and automotive stores. Follow the directions on the degreaser for use. The best type of degreaser uses a water rinse after the grease has been dissolved by the solvent. If you don't have the degreaser
You also will need a small amount of grease. The best grease that I know of for this purpose is Phil Wood bicycle grease (available
If possible, you also should have a new set of bearing balls on hand. If you buy new balls, get a couple of spares
I would suggest that you start with the front wheel if you have not done this job before, because there are fewer complications. Before you remove the axle; check to see if it is bent. Remove
Lift off the washer and unscrew the cone (The washer has a «key» or tab which slides in a groove cut in the threads of the axle.) Once the cone has been removed from one end of the axle, the axle can be pulled out of `the hub, and the ball bearings will fall out. There is no need to remove the other? cone and locknut that are still on the axle, so save yourself a lot of trouble and leave them on the axle, unless your old axle is bent and has to be replaced anyway. Remove the dustcaps by care- fully prying them up with a screw driver. If you have trouble getting the dustcaps off, leave them on rather than bending them. This will make it a bit harder to clean out the hub.
The most important part of this job is getting all the internal, parts as clean as is humanly possible. The inside of the hub shell, the axle, cones and balls must be completely free from old grease,, dirt: dust and solvent. If you don't remove all traces of solvent, the solvent will attack the new grease you will install later and the whole procedure will have to be done over again far too soon. If you are reusing the old balls, they should be cleaned especially thoroughly.
Now that the' parts are clean, they should be carefully examined for wear. The cones should have a shiny track running around them where the balls roll against them. Examine this track very carefully to see if there are any irregularities or pits. A magnifying glass may be of help here. If there is any sign of a flaw, no matter how small, the cone should be replaced.
Examine the cups (in the hub she'll) in the same way. In most cases it is not possible to replace the cups without re placing the whole hub, but fortunately the cups usually are the last parts to wear out. If the hub is cleaned regularly, lubricated and kept in good adjustment, the cups should last indefinitely.
If you are going to reuse the old balls, check them very carefully. They should have a perfect
It is particularly important that all
of the balls in a given race come from the same production run. They are made to tolerances of 3 or 4 millionths oversize, while the next batch may be 15 millionths undersize. If some of the balls in a race are that much smaller than others, the smaller ones might just as well not be there, because only the larger balls will be taking the load. Most front
If you removed the dustcaps, the first step in reassembly is to put them back in. This is done by gently tapping them into the hub shell with a hammer, working your way around the outer edge of the cap- Then line both cups in the hub shell with grease. Don't worry about using too much. It is not possible. If in doubt, use more. Lay the wheel on its side, and insert the end of the axle that does not have a cone on it part way into the hub from above. (If you are doing a rear hub, make sure that the axle is going in the same way it came out, so that the long end will be on the free- wheel side.) With the axle blocking the hole in the barrel of the hub you can install the balls in the upper cup with- out any risk of having them fall through.
Now, lift up the wheel and let the axle drop down so that the cone rests on the balls that have just been installed in the cup Hold on to the axle and turn over the wheel. Don't let go of the axle until it is resting on your work surface, or the balls may fall out. Install the, balls in the other cup and screw on the remaining cone to the axle hand tight. This will secure the assembly so that you can now handle it without risk of dropping bearing balls on the floor. Install the lockwasher and locknut and you are ready to adjust the bearing.
Adjusting ball bearings of the type, used on bicycles is not difficult, but if you haven't done it before it is likely to take some time and patience. Don't be in a hurry
What is meant by «adjustment of bearings» in the case of hubs is basically how far apart the cones are from one another on the axle. If they are too close together they will pinch and bind against the balls and the `axle will be difficult to turn. This means that the bearing would have too much friction and the parts would wear out prematurely. If the cones are too far apart, everything may roll freely enough, but there will be looseness or play in the bearing, and your wheel will wobble from side to side like loose tooth. The ideal is to find the point where the cones are loose ,enough that the axle turns as freely as it does when the cones are too loose, but with as little play as possible.
It is meaningless, to try to judge the cone adjustment when the locknuts are not tight, because, when you tighten the locknut, it changes the cone adjustment. What you have to do is to try different adjustments, checking
To check for friction, pretend you are a safecracker and the axle is the knob of a safe. Turn it slowly and smoothly, several revolutions in each direction. It should move with the gentlest pressure, Without any unevenness or binding. If you are not sure whether it is binding or not, try loosening one of the cones a bit. If it turns any easier, the previous adjustment was too tight.
To check for play, see if you, can get the end of the axle to wiggle up and down or side to side. If there is play you should be able to feel ft with your fingers.
It should be possible, to adjust
`No binding with no play is the proper adjustment
This can be checked by lifting the bicycle off the ground and trying to wiggle the rim back and forth between the brake shoes. There should be no rattling sensation. `Now keep the bike off the ground and let go of the wheel. The weight of the valve should be sufficient to cause the wheel tp swing back and forth several times before the wheel comes to a stop with the valve (or whatever
There is an additional complication when you are working on a rear hub, because the freewheel block gets in the way. If you have the necessary tools (a free wheel puller to fit your brand of freewheel and a sturdy vise mounted on , a solid workbench), the easiest approach is to remove the freewheel first. if this is not possible, you can do the job without removing the freewheel. Remove the locknut and cone on the left side of the hub and pull the axle out `from the,, right side. You will just be able to get at the right bearing cup through the center of the freewheel.
It will not be nearly as easy to clean the right cup with the freewheel in your way, but fortunately that side rarely gets dirty be, cause the freewheel makes it hard for dirt to get in. Be careful not to get solvent inside of the freewheel mechanism While you have the axle out of the hub, tighten the spacer for the right end of the axle tightly against the locknut and cone so you will be able to use a wrench on the spacer to hold the axle when you are adjusting the cone on the left.
The hubs should be repacked at regular intervals as part of the normal maintenance of your bicycle. How often it is necessary will depend on how much you use your bike and under what conditions. If you only ride on sunny days and have good luck you might be ,able to go a couple of years, but if you ride in the rain, or if you live in a sandy or dusty area, you may have to repack Your hubs every couple of months. The interval can be extended considerably by installing external seals to block the entry of dirt. (See Sealing Your Bike Components for Under $ 10 by John Allen, July 1977 Bike World.)
Rather than repacking your hubs on a fixed schedule I would recommend that you periodically check the condition of your hubs by removing the wheels and feeling how freely you can turn the axles (in the same manner described previously) Do not be fooled by the fact that your hub may seem to have «just a little» friction. Frictional drag is proportional to the load on the bearing. When you are, holding the wheel and turning the axle by hand the only load is the Weight of the axle set. When you are riding your `bike, the load is the weight of you and your machine, and the frictional drag is increased proportionally. You can feel the difference.