Quick release hubs have hollow axles that flex slightly when the quick release is closed. Hub bearing adjustments must account for this extra pressure. When a quick release hub is not clamped tight in the frame, there should be a slight amount of play in the axle. This play disappears when the hub and wheel are clamped in the frame.
Bearing Adjustment and "Feel"
Bearing surfaces are made from hardened steel. The surfaces are cut typically by grinding. Round ball bearings roll on the curved surface of the cup and cone. Even the highest quality bearing surfaces will have slight grinding marks. In the left image above is a high quality cone magnified two hundred times. Notice the parallel marks from the grinding stone. Also note a slight pit from wear. The right hand image is a bearing magnified the same amount. It does show some surface marking, but is generally smoother than the cone or cup. Bearing surface smoothness will vary between manufacturers and between models. Some bearing system will simply "feel" smoother because they are smoother. This is why it is difficult to adjust by using a subjective feeling of smoothness. Generally, adjust bearings for the loosest setting that has no knocking or play, regardless of this relative smoothness.
The following adjustment procedures simulate the on-the-bike compression while still allowing access to the left side cone and locknut for adjustment. The bicycle frame and skewer act as a holder for the wheel and the axle. The set up of the wheel on the frame may seem unusual. Follow directions carefully. An alternative to the procedure below is to adjust the bearings with the wheel unclamped. Mount the wheel in the frame to test the adjustment. Remove as necessary, adjust, and re-test. 1 Mount bike in repair stand.
2 Remove rear wheel from bike. If adjusting front wheel, remove front wheel as well.
3 Remove quick release skewer and springs. Remove any rubber boot covering left side cones and locknuts.
4 Insert skewer through cog side of hub. Install quick release adjusting nut on non-cog side. There must be a gap between the skewer adjusting nut and the locknut. The quick release nut must press only on the axle, not on the locknut.
5 Place cog side of wheel into left rear dropout. Non-cog side sits outboard of the bike, and is accessible to mechanic. If the cogs touch or interfere with the frame, remove rear cogs. Front wheel: either left or right side goes to rear dropout. Adjustment is done from side opposite clamped side. 6 Adjust quick release until tension is same as when normally clamping wheel in bike. Resistance to closing should begin half way through swing to fully closed. If in doubt see Wheel Installation .
7 Check bearings for play. Hold end of axle on non-cog side with one hand and rock rim laterally with other hand. Play in bearings will be felt as a knocking in the axle. If play is felt, proceed to step #9 below.
8 If no play is felt, adjustment is potentially too tight. Purposely create excess bearing play as the first step to proper adjustment: A. Use a cone wrench and hold cone from moving. Note position and angle of wrench.
B. Use another wrench on locknut. Turn locknut counter-clockwise to loosen.
C. Loosen cone by turning cone wrench counter-clockwise about 1/4 turn, or 90 degrees.
D. Hold cone from moving with cone wrench and tighten locknut. Locknut must be fully tight before play can be checked.
E. Test for play by holding axle and moving rim laterally.
9 If play is felt, adjustment is too loose. Tighten adjustment: A. Use a cone wrench and hold cone from moving. Note position and angle of wrench.
B. Use another wrench on locknut and loosen by turning counter-clockwise.
C. Recall angle of cone wrench and tighten adjustment by turning cone clockwise 1/32nd of a turn. Imagine cone wrench extending to the rim. Move end of wrench only the distance from one nipple to the next at the rim. This approximates 1/32nd of a turn for thirty-six and thirty-two spoke rims.
D. Hold cone from moving with cone wrench and tighten locknut. Locknut must be fully tight before play can be checked.
10 Test again for play by holding axle with one hand and moving rim laterally with the other hand. Rotate wheel and check for play all the way around wheel rotation. 11 If play is still present, repeat adjustment step above until play just disappears. Remember to make small adjustments clockwise one at a time. Check for play at rim after each adjustment. It is likely it will take several small adjustments.
12 Once play has disappeared, test final adjustment. Open skewer partially (about 45 degrees) and check again for play by rotating wheel and checking several points. If play is felt during this test, hub is adjusted.
13 If no play is felt during final skewer check, the adjustment is too tight. To adjust, first CLOSE SKEWER , loosen locknut and loosen adjustment only slightly. Tighten locknut and check adjustment for play, then test again by opening skewer to 45-degreee. Adjustment is finished when there is no play felt when skewer is closed, but some play is felt when skewer is partially open.
14 Remove wheel from bike and return skewer and springs to normal position. Replace any rubber covers. Notice there is play in axle. This play disappears when wheel is clamped in place for use. You must use the same skewer setting for riding as for adjusting the hub.
15 Remount cogs, if removed, and install wheel into bike. It is necessary to duplicate the quick release setting of hub adjustment when installing wheel.
Misc. Notes: If hub will not adjust smoothly, the bearing surfaces may be worn out. If play does not disappear until bearing adjustment is very tight, right side locknut may not be tight against cone, or cups inside hub shell may be loose.
Hub adjustment - Solid axle type
Non-quick release hub systems use axle nuts and washers on the outside of the dropouts to hold the wheel in place. Adjustment of solid axle hub bearings is similar to the hollow axle quick release type, but there is no need to allow for axle flex. Mount the wheel in the frame similar to quick release hubs as described above. Tighten the axle nut inside the dropout that is holding the wheel. The axle is now held tight. Check for bearing play. If no play is present, create play by loosening bearing adjustment, then adjust in small increments until play in gone. The goal is to find the loosest adjustment that has no play. Remove the wheel from the bike. The adjustment for solid axle hubs does not change when mounted in the bike.
Cartridge bearing hubs
These types of hubs use an industrial-type bearing unit. The inner and outer rotating races and ball bearings are installed as a unit. These hubs are not serviceable in the sense they are overhauled and adjusted. When the cartridge bearings are worn, rough, or have play, the cartridge should be replaced. The bearing unit is then removed and a new one pressed in. This requires special tools and is best left to professional mechanics.
本文转自：China Industry News
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