de-rusting bike chains & sprockets?
 

What do people here do w/ bikes for other people to help them salvage their bikes that may have been sitting outside just a little bit too long and they don't want to spend the money on new sprockets & chains?

What types of chemicals will remove rust?

I don't know about chemicals to remove rust but if I were doing it I'd get a brass brush and hold it against the chain while pedalling backwards. Hold the brush against all the surfaces that are rusted until it's cleaned. After that I'd flush the chain with lube, wipe as much off as I could and repeat several times. Depending on how badly it's rusted this may or may not work. Even with this though, replacement is the best answer and if the chain is badly rusted I wouldn't do the work because if the chain snapped during a ride and wrapped up someone could be in for a rough landing.

Sprokets are easy. just get a flat popsickle stick and something abrasive. or you could just get sand paper and fold it several times to make it stiff and sand away. I use a mixture of gasoline and motor oil, 20 parts gas and 1 oil. (its what I have lying around)

Chains are not reusable. they are consumable like brake pads and tires. chains stretch, and believe it or not, they become brittle if not lubricated and maintained. BUY a new chain. they are $4 to $10 if you have a 5-7 sprockets in the back.

If you use the old one you are not gonna have fun. Its an accident waiting to happen, they snap on the worst possible times, when you are putting some pressure on the pedals (like climbing up a hill). You wouldn't re-use old worn out brake pads, why the chain?

here is something similar. you dont have to buy this, just get something similar.

http://oldroads.com/clean_kit.html