Which is better, oil or grease lubrication?
Um, you have an interesting question, unfortunately the answer is long. Both oil and grease have their places. Oil is best for sliding parts and those which require high speed motion that are maintained regularly. Take a car engine. The bearings are sleeves which allow parts to “slide”, and these bearings are generally immersed in oil which is regularly changed to avoid contaminants damaging the bearing surfaces. Grease is best for long term applications where movement is benefitted by roller bearings. There are exceptions however. Take a common technique known as “trackmens slack”. This is used in track hubs where the bearings are lubed with light oil and run very slightly loose. This is as close to a friction free surface that you could imagine BUT it takes constant maintenance. Regarding your conundrum with the bottom bracket, keep in mind that in the early days many people didn’t possess tools of any quality so bike builders had to make it easier for common extended maintenance, th
