Bicycle Mechanics - Wrong kind of grease?

I was thinking to pose an innocent question when I asked a few cyclists what kind of grease would be bet for the seat post I was going to put back into my bike.

Seat post is aluminium
Frame is steel.

I was sold copper grease in the shop and only later received some of the advice I had been looking for.

It varied from
- lithium grease
- any type of grease will do
- copper grease
When I told to participants on one of the lists that I had elected copper grease one of them exclaimed that copper grease was exactly the only WRONG kind of grease as it wasn't as good for use in two different alloys (here aluminium/steel).

Now I'm puzzled.. and wanted to ask more folks!
What do YOU think?

Ivana

I might be wrong but if my memory serves me correctly, most of Aberdeen University's mountain bike club used Copperease and no one ever had any problems, or a stuck seatpost for that matter. Mind you, we all has steels frames in those days. Eeeeee, when I were a lad, we had to walk 15 miles to school through t'snow and rain etc etc. :D

I think what fietser_ivana is concerned about is the aluminum post fusing with the steel frame. This is a very legitimate concern.

I don't know about copper grease, but I can understand that copper, might cause a problem, but that is a guess on my part.

It will be interesting to see what answers come from the forum scientists and engineers. In the meantime, though, why don't you use a different grease. If you are in a pinch for grease, you can temporarily use Vaseline.

Well, I already BOUGHT the copper grease now and have used it. I'm puzzled as to why there are differing opinions on this!
I do suppose that metal seat posts are made from aluminium?

Ivana

I do know that the copper in the Copperease will oxidise before steel Ie be a sacrificial anode.

I'm not sure about aluminum, I suspect from it's position in the periodic table the aluminium will oxidise before either the copper or the steel. Aluminum posts are always either painted or anodised (oxidized) already anyway so that shouldn't be a problem.

Therefore it seems likely that using Copperease will be perfectly safe and stop the seatpost corroding into the frame.

Not sure what copper grease is, but it sounds a lot like Ti prep (anti-sieze which contains copper). I don't think the copper will introduce galvanic action, it's just overkill. Were there any instructions regarding usage on the copper grease container?

Here's a the breakdown of acceptible lubes I found on another list.
ti to al= Ti prep,copper anti seize
ti to ti = Ti prep, copper anti-seize
ti to steel= grease
steel to steel= grease
al to steel=grease
al to al= grease
carbon to anything = dry and immaculately clean and only to coated surfaces.

It just says
Putoline Copper grease is the ideal assembly and anti-seize compound.

Ivana who never thought she'd be discussing the ideal characteristics of grease for bicycle seat posts ;-D

Copper grease is an antisieze, and just right for your purpose.
I make do with lithium grease, the same as for bearings, and it works OK.
Do you use the copper for bearing lube? Can it be used for this?

No, the mechanic who sold it to me said specifically that this type of grease wasn't the best for ball bearings, but would be best for jobs like this one
- sticking a seat post into a seat tube
or :fight:
- a head set into the head tube..

Ivana