When do I need a new chain?

[Megster]

Hi!
Still a newbie. My dear bike stayed outdoors for the winter #fighter #mymistake
As expected the chain is rusty and I will change it with a help of my friend. But how can you tell that you can still save a bike chain? It doesn't look completely worn out. How do you guys "revive" a chain? Is it even worth it? Still learning, thanks!

   

[Jesper]

(05-09-2022, 06:06 AM)Megster Wrote:  Hi!
Still a newbie. My dear bike stayed outdoors for the winter #fighter #mymistake
As expected the chain is rusty and I will change it with a help of my friend. But how can you tell that you can still save a bike chain? It doesn't look completely worn out. How do you guys "revive" a chain? Is it even worth it? Still learning, thanks!

Tsk,Tsk Megster! Even though it was left outside, with rust showing on the chain it is a good indication that you weren't properly lubricating the chain in the first place. Excessive lubrication is, for the most part, better than insufficient lubrication. I have seen chains left outside for years (I know since I bought the bikes they were still mounted on) that had essentially no rust. Granted, they were a mucked up mess, but still quite functional and not beyond the wear limit.
If the chain was new and you have not put any great degree of mileage on it, I doubt that the actual chain is worn out/stretched beyond the 1% elongation (I generally use .5-.75% as a rule of wear due to utilizing vintage cogs which already have some wear on them) considered to be too much wear.
If you measure your chain (1/2" pitch) from link to link (from pin to pin center points; includes 3 pins) it should measure 1" when new. It is hard to measure wear over just on link so measure it over 10" or more. If you measure 10 complete links on a new chain it will measure 10"; a worn/stretched chain will measure 10.1". Many measure a full foot's worth of chain and go with 12.125" or 12 1/8" (approximately 1% "stretch") as being worn and needing replacement. I generally go with 12.0625" or 12 1/16" (approx. 0.5% stretch) to 12.09375" or 12 3/32" (approx. .78% "stretch") as being worn out and needing replacement. My numbers are based upon my riding habits, shifting requirements and type of equipment (vintage, old, classic, etc.) I am using.
If you are a casual rider and your equipment is not overly expensive then you might be able to utilize a worn chain for a longer period of time if function is still good, but you will end up needing to replace the chain, and both front and rear cogs that you use the most (the unused or barely used cogs on the chainring and cassette should still be okay). High end and/or rarer vintage parts cost more, and replacing a relatively inexpensive chain is a much cheaper fix. Newer and lower end bikes are probably not quite as expensive to replace multiple drive parts (chain and cogs) so you may be able to replace them with too much cost.
Should your chain prove to be within the parameters of an unworn chain then you will need to thoroughly clean it and the front and rear cogs. You do not want to go through what I do when cleaning a chain, even though it is the best and most complete (albeit time consuming) method unless you are an avid cyclist, a professional, or just nutty/anal like myself. I do recommend that you remove the chain (easy to do if it has a "master" link) and have a bike shop (or yourself) measure it for wear. Seeing the condition of your chain, I would recommend using a wire (steel-preferred or brass) brush to initially clean the chain and cogs on all sides. DO NOT USE A WIRE BRUSH ON YOUR ALUMINUM COGS/PARTS; use a stiff plastic brush instead. You can use a plastic brush for everything, but they tend to get torn up easily. Submerse the chain in a solvent bath (gasoline works great); and do it again in more clean solvent (and again if solvent is still quite dirty). You can then either bathe the chain in alcohol (rubbing or denatured) to remove any further debris and residual solvent) and lubricate; or just let it thoroughly dry and lubricate.
Realize that if your chain got rusty you may also have some moisture damage to bearings (especially if they are not sealed), and they may need service or replacement.
There are quicker methods of "cleaning" the chain, but they do not do a thorough job and tend to just clean the external areas and not the internal pivot/roller areas where wear will continue. The cartridge cleaners fall somewhere in between the external wiping and the solvent bath immersion method.

KEEP YOUR BIKE COVERED UP IF OUTSIDE! BETTER YET; STORE IT INSIDE! ALWAYS KEEP IT PROPERLY LUBED!

[ReapThaWhirlwind]

If you could remove it, and put it back, you can soak it in Evaporust to remove the corrosion.

However, then you would need to soak it in synthetic motor oil, cause it can become seized after Evaporust.

Easier to just buy a new chain really. I wouldn't want to ride it that way.

[Criminal]

"Evapo-rust" and "WD40": the wonder solutions to everything! Wrong! Do no use evapo-rust on polished/machined load bearing surfaces! You more than likely only have surface oxidation/rust. Do not use a product like this that will penetrate into the engineered surfaces. Either clean, lube and use your chain; or just get a new one. A little time and effort might make your chain perfectly useable unless there is excessive wear from prolonged use or improper maintenance. Why immediately toss out what might be a good functioning part unless it actually is worn or severely damaged enough to cause damage to other parts. I've used chains that have been frozen with oxidation only to have them provide 100s of miles of use without causing ill effects to gears. Just clean your parts and lube if a wear measurement shows the chain is still within proper limits. Do not waste more money on a rust treatment product; instead buy a decent lubricant. A wear test is cheap (if not free) and super quick. You probably already have what you need to effectively clean and lube it so save your $ and spend a little time instead. I can almost guarantee that your chain is actually fine after cleaning and lubing. Clean those gears as well; you would still need to do that whether you keep your original chain, buy a new one, or waste money and time "evapo-rusting" your original chain. Do not use WD40 as a lubricant for your chain; either old or new. Make sure there are no "stiff" links (every pivot point moves freely) after proper lubrication. If there is still a problem stiff link or 2 then you should replace the chain regardless of wear since that can adversely affect shifting, etc. If you know a friend with a bike, clean and lube their chain also if removing yours; it is just as time consuming to do 2 or 3 chains by dunking them as it is to do one. Invest in a chain removal tool (inexpensive) if you want to maintain you own bike unless you have the special links to readily remove it. The master links are dirt cheap also if you want to add one to your chain for easy future removal and maintenance whether on an older or new chain.
Here's an easier solution: toss the whole bike and get a new one! Sorry, not really; a little effort will go a long way towards saving you a lot of money and provide to you the experience to help yourself and others in the future.

[ReapThaWhirlwind]

Evaporust works by chelation reaction. It's safe to use for auto, so it's definitely safe to use for your bike chain.

It simply remove the rust, and may remove non-adonized paint, but otherwise only takes it down to the bare metal.

[Criminal]

I guess you could spend about $10 to "evaporust" (prior comment: " it can become seized after Evaporust") your used chain (which might be overly worn and not worth the effort or $), or spend $10 on a new chain. Pretty easy choice there. I would still have it checked for wear; if good you can still keep it as a back-up part; just dunk it in oil and bag it up.

[Joseph Williams]

I think the chain wasn't lubricated enough. So my advice is instead of trying to revive it put on a new chain and maintain it properly. With proper lubrication.