TripperAdam

This winter I rode my Gt Nomad over the usually salty slush of Toronto streets. However I was only out about 8 times on the road so I didn't really feel the need to do any maintenance over the winter season. When I went to my shed this spring and pulled out my trusty steed I discovered rust and a sort of white build-up on the spokes, brake levers (the brake part not the hand lever), derailers and a few other components. The chain was totally rusted out so I replaced it, but the other components seem to have more of the white stuff than rust. There is way too much for it to just be caked on salt, it won't wash off easily.

Has anyone experienced this sort of corrosion on their bike, and if so are you aware of any way of removing this crap so I can enjoy a nice clean bike.

Thanks a bundle

HillRider

It's corrosion of the Al parts caused by salt exposure. "Only 8 times" with out any cleaning or washing is plenty of exposure to salt to cause the problems you are seeing.

What you describe is typical for corroded Al and while aluminum won't "rust" it will certainly corrode under the right circumstances. There is a product available called "Aluminum Jelly" that should remove the corrosion but any pitting or other damage will, of course, remain. This stuff won't replace missing metal. Be sure to wash it off very well and relube everything.

cyccommute 

Ooh! Ooh! Chemistry lesson! What you have experience TripperAdam is truly rust of the aluminum. Rust is oxidation of iron in steel parts to form an oxide of iron. With the aluminum you have a similar situation in which, eventually, the chloride ions in the salt form aluminum chlorides and eventually aluminum oxides. That's the white stuff you see.

Sodium chloride (table salt) and magnesium chloride (mag chloride, ice slicer, etc) contain lots of chloride ions. Mag chloride actually contains twice as many chlorides than sodium chloride per unit weight. Chlorides absorb moisture from the air which is all you need to start them moving around. Here in Colorado, our relative humidity is low (typically less than 25%) but you can still get corrosion pitting of aluminum because the salts will absorb even a small amount of water from the air. In areas with higher humidities, the salt will absorb enough water to make the salt liquid (leave a few salt grains out on a table and see for yourself). That liquid will just sit there and chew away on your parts for as long as the salt is in contact with the metal. End result? Aluminum 'rust'!

Remove the stuff on there as HillRider has suggested. In the future, it would be best to rinse the salt off after your ride...even in winter. The damage is probably cosmetic. Removal of the salt will allow the protective oxide layer to form again and stop the damage.