Bearings
A basic bearing system is shown left. The cup is normally a permanent press fit into the hub shell. The cone traps the ball bearing. The locknut is tightened against the cone to prevent the cone from moving. If there is looseness from bearing play, the cone can be move closer to the cup.
Freehubs
Cup and cone type freehub
The modern freehubs tend to be more complex. The hub will have a freehub mechanism attached to the hub. The cassette cogs attach to the freehub. It is possible to remove and service the freehub in a separate operation. See Freehub Service. A typical rear hub with freehub is seen above.
Cartridge Bearing Hubs
Common cartridge bearing type hub Hubs using the cartridge type bearings are not serviceable in the sense they can be dismantled and adjusted. As cartridge bearings wear and develop play, the entire cartridge unit is replaced. Cartridge hub service is not covered in this article.
Hub overhaul
1 For rear hubs, begin by removing rear cogs . Remove quick release skewer. If it is a solid axle type, remove axle nuts.
2 Inspect axle ends. Measure and note the amount of axle protruding past locknut. For quick release hubs, counting the number of threads is an adequate measurement.
3 (OPTIONAL) Mount in axle vise, if possible. Mount right side down with left side facing upward. Generally, dismantle from the left side.
4 Remove any rubber cover. Use a tie or string to hold small parts in the same orientation as they came off of hub.
5 Hold cone using cone wrench, and loosen locknut counter-clockwise
6 Remove locknut and any washers, placing them on the tie.
7 Remove cone by turning counter-clockwise.
8 Place hand below right side, and lift wheel slowly. Be prepared to catch bearings that fall from hub. Place wheel on bench.
9 If inspecting bent axle, remove right side locknut and cones. Note that left side and right side cones, washers and locknuts may be different. Do not confuse left and right side parts. Use tie method to keep track of parts. Also note axle thread may be asymmetrical. The side with more axle spacers gets more axle thread.
10 Count the number of bearings on each side, and then use pencil magnet to remove bearings from hub shell.
11 For many hub models, it is possible and recommended to overhaul with the pressed dust caps in place. Dust caps may be fragile and removal may result in damage. Work around dust caps when cleaning and inspecting. 12 Wipe and clean all parts. Parts must be dry for assembly. Wipe freehub mechanism out using damp rag. Do not soak freehub in solvent. Freehub bodies are lubricated internally with a light lubricant, and soaking them with solvent will remove lubrication. For freehub service, see Freehub Service.
View hub cups and cones for pitting or damage. Also use a ballpoint pen to trace the bearing path. Roughness and wear will be felt as the small ball of the pen passes over pits.
Inspect ball bearings for shininess and brightness. If balls are dull looking, they should be replaced. If the cup is damaged, it typically cannot be replaced. A new hub would be required. Cones are typically available as replacement parts.
If inspecting axle, roll axle on flat surface. View axle close to surface and watch for gap appearing as axle rolls. Bent axles cannot be re-bent. A new axle is required.
Hub Assembly
1 Grease axle threads.
2 Grease heavily inside hub shell cups. Place ball bearings in both cups and cover with more grease. Make sure balls are seated flat in cup. For rear hubs, the common number is 9 balls of 1/4-inch diameter per side. For front hubs, the common number is 10 balls of 3/16-inch diameter per side.
3 If all parts were removed from axle, install right side parts. Use care to install in the same orientation as they came off. Return axle protrusion to the original measurement, as noted earlier. Tighten cone locknut fully.
4 Install axle through right side of hub.
5 Install left side axle parts, using care to install in the same orientation as they came off. Do not set axle protrusion on this side and do not tighten locknut at this time.
6 For quick release type hubs, snug the cone down until it contacts the ball bearings, and turn back counter-clockwise one quarter turn (90 degrees). This will purposely make the bearing adjustment too loose. Hold cone with cone wrench and tighten locknut fully. Proceed to Hub adjustment below.
本文转自：China Industry News
本文链接：http://news.made-cn.org/post/cartridge-bearing-hubs.html