Grease or not to grease inside the bottom bracket tube?

[knurt]

Hi!

I have bought a BBSHD an a brand new aluminium frame bike. This is my first post and my first ebike-build.

When I removed the bottom bracket I noticed some kind of white grease inside the bottom bracket tube. I now wonder if I ought to rub this grease away with a cloth before installing the bbshd in the bottom bracket tube, or perhaps I ought to add some grease in the bottom-bracket tube instead? If so, what kind of grease?

Would appreciate if someone could help me with my questions.

Best regards!
/knurt

[73Eldo]

The grease in there is most likely just something that leaked out from somewhere else. If its ever going to get wet having something in there so you can get it apart again someday would not be a bad idea. Some kind of grease is Ok especially if you have it around. Regular bicycle grease will be a lot better than nothing especially since this will be mixing steel and aluminum. If you don't have anything and need to go out and buy something then maybe getting an actual anti seize product would be best. You don't need a ton of product in there just enough to coat the surfaces. There are often drain holes down there that you don't want to block in case water does get in, it needs a place to get out.

[knurt]

thank you!

[longboardguy]

I too would suggest using some kind of anti-seize or grease especially if the bike is used near salt water. Mine is frozen tightly in the BB tube from corrosion. I wish I had coated the shaft before building the bike.

[Robert07]

If you plan to do your own bike maintenance, the greases for the bottom bracket from Park Tool are worth it. I've used it to repack wheel bearings on a bike that had not been maintained in a while (the wheels were not spinning freely). Once the hub and bearings were cleaned, with the fresh grease, the wheels spun smoothly and quietly. It repels water with ease and doesn’t run off when going through large puddles or encountering rain. I didn’t have to reapply once last summer, even though it was raining almost daily.

[Dshue]

Use an anti seize compound. Even if you never ride in rain or through standing water you will still get condensation in there. And that will add to the effects of the galvanic reaction that will already be taking place due to the aluminum vs steel.
If you look you'll see a hole in the bottom bracket leading into the seat tube and down tube, this is how the condensate gets into the bottom bracket.
Grease isn't good at stopping galvanic reactions.