Confused ref bb grease instructions

larkim

New es25 bottom bracket has arrived and I'll be fitting it later. This will be a first for me!

Checked out parktools website and it says "Plastic lockrings or cups need only grease on the threads. Do not use thread lockers on plastic as the chemical may cause the plastic to become brittle." I don't have thread locker so grease it is.

But the shimano instructions which came with the bb suggest that the plastic lockring threads shouldn't be greased. See https://www.dropbox.com/sc/ap1qfu3kxke8gam/wdUC3ibiX0 for a photo of the slightly ambiguous instructions.

I can't see tf2 grease being an issue on plastic threads, but don't want to make a hash of this!

Cheers!

Matt

cooldad

Don't think it'll make a massive difference one way or the other, but when contradictory stick to the manufacturer's advice, so grease on the metal drive side cup, nothing on the NDS if it's plastic.

larkim

Cheers. I suppose plastic isn't going to seize to the frame anyway, but I was imagining grease would help as a moisture barrier down there. Sound advice though, thanks!

bikaholic

The plastic lockrings do seize up so I would advise greasing it as well as any other mating surfaces.

When I install BBs, what I do is write the date of installation on it before smearing a layer of grease on its surface in order to protect it from liquid ingress from the top of the seat tube.