Which is better, oil or grease lubrication?

Question

I have a very old tandem which has oil ports on the bottom bracket. I was going to repack it with grease, but I thought that perhaps it would be simpler to use the oil ports - meaning that I would not have to fiddle around with the bottom bracket and cotters every year. Is oil lubrication good? Can anybody tell me the pros and cons of oil and grease lubrication in both bottom bracket and hub bearings?

Answer 1

grease lasts longer and works better //

Answer 2

use the oil ports the way they were designed.

oil will leak out of things supposed to be greased.

grease wont lubricate things supposed to be oiled.

dont use the back of a screwdriver when the right tool is a hammer.

Answer 3

Slow moving bearings need grease, but the cheap (let's save money) manufacturing process called for you to fit your own grease nipple.

Grease is longer-lasting than oil, as the oil runs out through the bearing in the first few minutes on the road, whereas grease will stay in the bearing for a long time.

Answer 4

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, thus the oil ports. The bad thing about this is that once the thing DID require a rebuild it was a horrible and expensive mess.

THAT BEING SAID, if your BB is an elliptical unit it is a good idea to put a couple (this means ONE or TWO DROPS) of drops in each port each month... but this does not eliminate the need for annual rebuilding.

Answer 5

my guess is you and whoever youre with laughed at the innuendo before posting this

you know im right

Answer 6

Some things need oil, some grease... You can't replace one with the other...