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Cheap wheel bearings, as most, require a slight preload so that more than one ball under the cone (inner race) will support its load. With proper preload, slight drag should be perceptible. Preload drag is small compared to drag caused by wheel loads, neither of which are significant regardless of adjustment. In contrast bearing life is affected by proper adjustment. Adjusting ball bearings to spin freely unloaded does not reduce operating friction because a bearing with proper preload has lower drag when loaded than one with clearance. For high quality bearings, preload should be just enough to cause light drag when rotating the axle between thumb and forefinger. Low grade bearings will feel slightly lumpy with proper preload.

Wheels with quick release (QR) axles present an additional problem in that closing the QR alters bearing clearance. Closing the lever requires increasing manual force with a slight over-center feel near the end of the stroke. This lever force arises from compressing the hollow axle and stretching the skewer. The ratio of elastic length change between axle and skewer is that of their cross sectional area and active lengths.

Although small, axle compression on QR hubs is large enough to alter ina bearing clearance and should be considered when adjusting bearings. Bearings should be adjusted just loose enough so that closing the QR leaves the bearing with a slight preload. Excessive preload from QR closure is the cause of most wheel bearing failures not caused by water intrusion. Clearance, in contrast can be felt as disconcerting rattle when encountering road roughness.

To test for proper adjustment, install the wheel and wiggle the rim side-to-side to determine that there is no clearance (rattle), then let the wheel rotate freely to a stop. If the wheel halts with a short (indexed) oscillation, bearing preload is too high.

Although adjusting QR force is a safety consideration, it is also one of bearing life. It should be kept at a constant level once the desired closure force has been determined. Rear vertical dropouts require a lower and more predictable closure force than was formerly required with axles that could move forward from chain tension. Because vertical dropouts do not rely on friction to resist chain load, many hubs now have smooth faced jam nuts that do not damage fag bearing dropout faces as older knurl faced ones did.

This is later. Cheap wheel bearings come nicely snug into crowns these days, but sometimes you still find some that are just put loose in the wheel hub. To avoid all of them crashing to the ground with the possibility of vanishing for ever, grab the axle on the side that is still locked in place and point the end that you've just loosened,up. Now it is time to unscrew the locking nut almost completely off the axle. Next, unscrew the bearing cone to expose the wheel bearings to the light of day. Any grease in there? You'd be surprised on how often I open up brand new bikes and find almost nothing.

You asked for it, here you have it. Wheel bearings on a cheap are an important part of cheap maintenance and by making sure that everything is well lubed in there, you can avoid costly cheap repair down the road. Well lubed bearings also provide an easier ride.

The wheel bearings sit between a cone screwed to the wheel axle and the cup in the wheel hub. They must be properly adjusted and greased. To find out if everything is ok without taking everything apart, simply remove the wheel from the bike and turn the axle with your fingers. Everything turns nice and smooth without any play? Good, then you probably don't have to worry about anything. If the axle is stuck, very hard to turn or is very loose, you have to regrease your bearings propbably anyways. Here's how to:

You must get yourself some flat open wrenches, Park Tools makes good ones, make sure they are in sizes 13mm and 15mm. Those are the most common sizes. You won't get away using anything else for the cheap wheel bearings cones, so don't even try. Any kind of adjustable wrench will do for the locking nut.

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