….on the bb threads?

Either will do but copper grease is the correct thing to use.

Wot he said, as they will do the same job for a BB but grease is actually a lubricant, to lube stuff and copper slip is to stop (contact) corrosion IIRC.

Copper slip for me. I rub it all around the inside of the BB shell so its totally covered, that way, when inevitably water gets in from around the top of the seattube, it completely protected…done it for years particularly on steel frames and when Ive come to sell the frames, I’ll remove the copper slip and the BB shell will look like new

Copper grease it is then. Thank you.

Just remember, wear gloves when using copperslip. Highly Carcinogenic!

I only use grease just for this reason.

So carcinogenic its sold in huge tubs and I’ve never seen a warning?

Well, it’s anedotal that Copper is a carcinogen – the medical research showed no increase in tumors with lab mice – so it’s been classed as pretty much ‘unknown’, as a Group 3 carcinogen.

Given that, it’s very unlikely to be highly carcinogenic. Certainly getting it on your fingers isn’t going to be an issue – eating the stuff for a few months might be a concern though.

Use anti seize (which is what copperslip is). The carcinogenic bit comes from the copperslip dust(it dries out) if its used in high temp applications, like on the back of car brake pads for instance or steam pipework etc. Personally I only use grease* on things that I want to move, ie not on threads.

*apart from silicone grease on O rings.

I use to use Copper grease at work a lot and I got cancer, in my throat, I can’t remember eating any though. 😀

It did get banned at work a few years ago though, but that’s more to do with the embrittlement caused in alloy steels at high (500C) temperature and radiation levels.

I normally apply to steel parts quite liberally with my finger. It’s not dropped off just yet but if it does I suspect it will be due to the much nastier things I put my fingers in!

Personally I don’t let copper slip anywhere near my bike. Horrible stuff that gets places you don’t want it and i don’t trust it on plastic parts etc. The tub stays outside for use on cars. I use it on steel bolts on my car but don’t let it anywhere near any brake seals.

On the bike I just stick to Shimano anti-seize (white ceramic stuff) or teflon loaded grease. Park tools anti-seize is also supposed to be good.