Originally Posted by
bikeman68
Put in some real riding, with a steady output in hills and rolling terrain in all weather, and you see a whole new view on the demands real cycling can put on bearings.and grease I have seen a few hubs /Bottom brackets and headsets ruined from grease failure ie washout. Only a select few Bicycle greases hold out in rain and high speeds , under consistent power outputs
So after me seeing damaged bearings riding with Finish Line and Park Polylube grease thru vigorous rides in rain, I'm a bit disappointed and can tell you only Phil Wood grease stands up to this test in my experience. If you do not have experience really putting bike components and grease to the test, then do not comment based on assumptions , you have not been a diehard cyclist to say that
Speeds and loads are very low on bike bearings. A bike going 60 mph only has 600 rpm in the hubs; the same bearing components get used in machines that spin at 10 times that, and see much higher loading. This is actually an issue for bike bearings. General purpose bearings have only a fairly low charge of grease, because at high speed, the bearings get hot, and excess grease increases friction and reduces the bearings ability to reject heat. (it can also lead to seal failure, when the grease expands or melts and blows out a seal.) Bike bearings never get that hot, so filling them with more grease gives them better resistance to washout and corrosion. Phil used pry the seals off the cartridge bearings they bought, and inject more grease into them.
Water and contamination are the only real dangers to bike bearings, and there are plenty of greases that deal with water. Not much grease can do if you fill the bearing with sand.
I do not use bike specific greases, because they're all relabeled stuff, no one publishes spec sheets, and what's in the tube is subject to change.