BICYCLE REPAIR
Overhauling
Hubs
The following advice is for loose-bearing types only. Rear hubs are described here because they are more complicated. Except for removing and installing freewheels and cassettes, front hub overhaul is identical.
Round up the following:
Remove the wheel. Unscrew and extract the quick release.
For conventional freewheels, install the proper remover. Insert, assemble,
and tighten the quick release (without springs) to hold the remover in place
(photo). On cassette hubs, insert the lockring remover,
place a chain whip on the largest cog in a position to turn it clockwise.
Hold the wheel upright on the floor. Position the adjustable
wrench on the remover. Loosen freewheels by pushing down
(counterclockwise) on the wrench. An alternative is to clamp the remover
in a vise and turn the wheel counterclockwise. Once the freewheel breaks
free, remove the quick release and unscrew the freewheel the rest of the
way.For cassettes, press down on the chain whip with your left hand while pushing down on the wrench with your right (counterclockwise; photo) to loosen and remove the lockring. Carefully lift off the cogs.
Clean the axle ends so you can see the various parts. Hold
the left cone and locknut with the proper size cone wrenches (alternatively,
use an adjustable wrench on the locknut). Turn the locknut counterclockwise
(photo). Unscrew it, remove the lockwasher and unscrew
the cone. Place each item on the rag in the proper order.
Pull
the axle out of the hub from the right side. With a small screwdriver
or magnet, extract the bearings from both sides of the hub. Using the
end of a cone wrench or a large regular screwdriver, carefully pry the
dustcaps from both sides of the hub (photo). If your
dustcaps are attached to the cones, don’t separate them.
Thoroughly clean the hub (poke a rag through its center),
axle, cone, locknut and dustcaps. Also, clean but don’t separate
the parts still on the axle. Examine the cones and hub bearing cups for
scoring or pitting (photo). Replace worn cones. When
replacing the one that’s still on the axle (right side), measure
the amount of exposed axle, position the new cone the same distance from
the end and tighten it securely against the lockwasher and locknut. Damaged
hub cups make proper adjustment impossible and will wear parts rapidly.
If this is the case, consider replacing the hub or buying a new wheel.
Coat
both hub cups with a thin layer of grease. Place half the bearings
(be sure to use the right size for your hub), in one side and cover them
with more grease (photo). Press the dustcap into the hub
by hand, then seat it gently with the rubber mallet. Repeat the procedure
on the other side. Use cone wrenches to ensure that the right axle parts
are securely tightened against each other. Push the axle into the hub from
the right side.
Thread
the left cone onto the axle by hand until it touches the bearings.
Install the lockwasher and locknut. Use cone wrenches to tighten the cone
and locknut against each other. A perfect adjustment will have a tiny amount
of play that will disappear when the wheel is clamped in the frame. Grasp
the end of the axle and move it up and down to check this. Turn the axle
to feel for smoothness.If it’s tight, place a wrench on each cone (if the right cone is hidden, hold the locknut) and turn the wrenches counterclockwise slightly. If the adjustment is loose, hold the right locknut with a wrench and move the left cone a quarter turn clockwise (photo) then do the same with the locknut. Recheck the adjustment. When it’s correct, use 2 cone wrenches on the left side to lock it in place. Grease the freewheel threads, screw it on clockwise, and tighten with a chain whip. Slide cassette cogs onto the body, add the lockring and tighten it with the tool and adjustable wrench.
This article
is based on one I wrote for the February 1992 issue of Bicycling Magazine.
The photos are by Mel Lindstrom. I set up the shots and appear in them.
The photos are by Mel Lindstrom. I set up the shots and appear in them.
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