Cycle Chain Rusted Tight - How to Unrust?

anotheruser

I have a bike chain on my bike that has been subjected to a good old bit of rust.

I managed to un-rust a lot using WD40 but there is one link that is rusted tight. So much so I tried using a hammer to try and loosen it but no go.

Used half a can of WD40 but still no go.

The chain goes round as I thought winding it round the circuit would loosen it up but even that hasn't, so now it makes a clicking sound each time it goes round

Any advice?

AndyBSG

My advice is to replace it!

If a chain has rusted so badly that it's not moving then it really is beyond saving. You may be able to get it moving again but even if you do you're going to risk damaging your cogs and derailleur by carrying on using it.

You'll also need to have a good look at your whole drivetrain if it's in a similar condition by checking the cogs, cog teeth, deraileur and possibly even the crank shaft.

You may get it all up and running in the short term but long term you're risking damaging other components.

ariba10

Give it a couple of good sprays with WD40 it will free it up in the short term, but as stated you should be looking to getting a new one.

forgotmyname

Heat.. Get it nice and hot. Then spray with wd40 or similar to quench it
and help it penetrate below the surface.

Or maybe cut that link out, Chains are not that expensive though.

Rosemary7391

You can't 'unrust' something. Rust flakes were once working, useful metal. So you've lost a bit of your chain. Most of the time it'll still work with small bits missing, but in this case it sounds like it won't for much longer even if you can get it moving again. I'd replace it sharpish - I wouldn't want to be riding it if the chain snapped or damaged something else!

mumf

You use the bike a lot then?
Seriously, replace the chain-and probably the rear sprocket too. You can't put a new chain on a crappy rusted sprocket.

anotheruser

Well, the chain and drive system came up pretty well after the initial clean, it was just this one link in the chain that was rusted tight.

I don't use the bike much. I gave it to a member of the family for the past 3/4 years but wanted to see if I could get back out on it then invest in a decent road bike. But because every time the chain goes round, there is a "twang" as the rusted link goes through the derailleur then it doesn't sound too healthy so puts me off.

Might give it another go after winter.

Thanks for the input - learnt a fair bit about bike drive systems

ILW

You have probably spent more on WD40 than a new chain would have cost.

Richard53

As others have said, treat it to a new chain. As a temporary measure, you could try spreading the stiff link slightly to ease it off. Locate the stiff pin, and work on the link with the side plates on the outside of the pin. Put a large screwdriver between the plates and twist it, or possibly gently tap with a hammer. You only need to spread the plates by a fraction of a mm to free it up. But, bottom line, the chain is scrap. New ones are cheap and you won't believe how much nicer the bike is to ride with a new chain.

Strider590

Replace it.......... You've already admitted to using WD40.

WD40 is primarily a solvent and it removes the pre-installed grease from inside the chain link rollers, it also draws dirty/grit into the links, leaving metal to grind on metal, WD40 is a very fast way to destroy even a brand new chain.

Replace the chain and use only bike chain lube in future.

http://bicycletutor.com/no-wd40-bike-chain/

johnmc

"in the old days" I remember my Dad soaking my chain in a pan of paraffin overnight and then melting some grease in a pan and soaking the chain in that for some time.

This was part of the annual service for all our bikes.

These days a chain is probably cheaper than the paraffin.