I've had far more problems with steel bikes in winter than with aluminum. :-) My experience has been that rust is to cancer as aluminum corrosion is to sunburn. Yeah, an over simplification, but it's been much easier for me to deal with the aluminum winter bike. I personally won't go back to a steel winter bike, but if I had to, I wouldn't lose any sleep over it.

You can't fit a bicycle with a sacrificial anode because you'd have to know what area the galvanic cell was going to form and unlike a boat which is totally covered in the electrolyte a bicycle will only end up partially connected(between fork and drop-outs say). Besides that magnesium is like the least noble metal so anything will corrode it so it's pretty hard to protect a magnesium fork all you can do is try to paint it or covered the exposed area grease.

The answer it to bring the bicycle inside or try to use metals with similar nobility, that will slow down any corrosion.

Here is what can happen to your nice fork if you don't keep the magnesium parts dry... this is after one season.

http://i52.tinypic.com/20pe9tg.jpg
http://i46.tinypic.com/207ls2c.jpg

Yes. No. And maybe.

Corrosion depends largely on conditions. Chlorides speed up the corrosion process on both aluminum and steel because the chloride facilitates galvanic corrosion. Because of all the dissimilar metals on a bicycle, galvanic potentials can be set up all over the bike. Having an electrolyte and water present, starts the reaction while removing one of them stops the reaction.

It is true that aluminum is more reactive than iron. But that reactivity passivates the surface rapidly since bare aluminum reacts rapidly with oxygen to form aluminum oxide. But steel also undergoes electrolysis and oxidation but it doesn't form a protective coating. The rust formed is more porous and allows further reaction.


They do this by allowing for more electrolysis. Salts of chlorides, especially alkali metal and alkaline earth salts, absorb water out of the air. With alkali metal salts ('salt' or sodium chloride being the most commonly used), the water absorbed is high but the salt tends to be very soluble in water. A little water just rinse it off and the salt 'dries', i.e. loses water, more quickly.

Alkaline earth salts, like magnesium chloride, absorb water from the air too. However, they absorb more of it and they are less water soluble. They tend to 'stick' in place and absorb water which is kept right next to the metal surface. This keeps the galvanic reactions going.

Here's a paper on Aluminum in salt water environments. It says that aluminum is corroded by salt water but that the salt water facilitates the galvanic actions. The oxide layer is also very sensitive to pH levels. Getting high (>8.5) or low (<4.5) pH really isn't all that difficult in our world so the oxidation layer can be damaged which starts the corrosion.

Yeah my poor 22 year old "BARE ALUMINIUM" RM is just falling apart.

I sweat so much my Steel Bianchi was rusted after 5 years of summer riding. I've ridden the RM the last 5 winters (5+ month long winters) and when it is encrusted in ice and sand and salt, I take it to the basement to melt, and just ride it the next day, and repeat. These rides are 1.5 - 2.5 hours in up to -35C, and the last 2 winters rider and clothes could be 300+ lbs (275 rider).
I've ridden in a lot of winters previous, but the last 5 years it has 90% ridden in the winter. I do use it when I commute to work but, that has been far too infrequent lately.


I should polish it up and take a picture, Flitz metal polish still makes it shine like chrome, but does take time.

I am more concerned about the original chromoly fork that the frame.

Titanium is best.

Carbon + salt + water can corrode very fast. You just need a deficiency in the supply of oxygen.:lol:

Titanium + salt + water can corrode very fast. You just need a deficiency in the supply of oxygen.:lol:

I would never ride an expensive bike in the winter, not with the crap I put them through.
The ol RM was $1000 back in 89, but it has lasted over 2 decades so I got my moneys worth.
It "was" an expensive bike but it is by far the least expensive of my current bikes, so it is by default my winter beater.

If I were to build a winter beater I would get a decent $2-300 (aluminium) frame and put low level parts on it
that when they get destroyed are easy and cheap to replace. That way you aren't spending more time
cleaning than riding.