For my the products I design, I have used and would use again NMB, NSK and SKF bearings. These are all ball bearing assemblies. For the vast majority of applications (including bicycles), even so called "cheap" Chinese bearings are more than adequate if they are properly lubricated. For non-competitive riding, an automotive wheel bearing grease will keep your motorcycle bearings happy for thousands of miles. I suggest solvent (70% isopropyl alcohol is fine) cleaning the balls, raceways, cones, etc, drying then immediately apply the grease to all the metal surfaces inside the bearing system. Use nitrile gloves - your finger oils are bad for bearings.

An important aspect of bicycle maintenance is to grease the motorcycle bearings. This helps to avoid costly future repairs and give you a much smoother, more comfortable ride. The wheel bearings are between the cup in the wheel hub and a cone screwed to the wheel axle.

Motorcycle 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 skf 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.

Motorcycle bearings support the wheel hubs on the axles. Bearings require a certain amount of pressure, otherwise referred to as preload. The specific amount of preload determines the number of bearings that support the wheel hubs at any given time. Cone flats thread onto the axles and press bearing cones against the bearings. Adjusting bearing cone preload prolongs the life of the bearings. With proper preload, light drag should be noticed when spinning the wheels.

Wheels with quick-release levers present a challenge. Closing the lever alters the preload. Adjusting iko bearings on wheels that have quick-release levers may take several attempts.

For the vast majority of applications (including bicycles), even so called "cheap" Chinese bearings are more than adequate if they are properly lubricated. For non-competitive riding, an automotive wheel bearing grease will keep your motorcycle bearings happy for thousands of miles. I suggest solvent (70% isopropyl alcohol is fine) cleaning the balls, raceways, cones, etc, drying then immediately apply the grease to all the metal surfaces inside the bearing system. Use nitrile gloves - your finger oils are bad for bearings.

An important aspect of bicycle maintenance is to grease the  motorcycle bearings. This helps to avoid costly future repairs and give you a much smoother, more comfortable ride. The motorcycle bearings are between the cup in the wheel hub and a cone screwed to the wheel axle.

"motorcycle 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.