Originally Posted By: miro
Back to the topic, The bicycle bearings are low demanding application Low speed, very low loads, temperature doesn’t exceed 40…42C.
Water washout and corrosion protection are number one requirements.
Given the bearing issues people have with bikes, especially bottom bracket bearings I'd disagree... To a point.
True, the temps are low but the demands on performance of the bearings in terms of weight, low drag and packaging are high.
Bikes, especially mountain bikes function in a dirty environment where the requirements of good sealing and low drag conflict. Additionally weight and the need to fit bearings in parts that meet certain size standards seem to mean that bikes sometimes end up with either poorly sealed bearing or bearings undersized for the load. Maintenance, of course, is a factor but who wants a BB or hubs you have to rebuild every week.
I'm surprised we don't see more bike parts with grease injection ports. I believe Suntour used to make hubs but otherwise nothing.