gthomson

Bike riding I've always done but bike maintenance is something relatively new to me and I used to just take it into the LBS every few years for a "tune up". I noticed the shifting on my newer road bike was starting to diminish so I adjusted the rear derailleur which improved things a bit but decided to take it to the LBS to look over. They said the chain was worn 100% and would need to be replaced along with the cassette. I didn't think to check the chain.

I then went home and checked my C&V bikes for chain wear but wondered how easy it would be to replace the chain and the freewheel? some of them I've replaced with new wheels and cassette but even then, not easy to find older cassettes these days. Do I leave it or get on this right away?

TBH they all ride nicely and I'm scared that if it ain't broke, don't fix it.

genejockey 

Chains are cheap. Cassettes - especially vintage ones - are expensive. A worn chain will wear out your cogs faster, so better to replace chains often and cogs less often.

davester

What @genejockey said. Also, a chain wear checker tool (Park and Pedro's make good ones) can check your chain in 5 seconds. Barring that you can use a steel ruler to measure 24 links of a taut chain (should be exactly 12" = unworn, 12-1/8" = shot, and 12-1/16" = time to replace

verktyg 

I bought this Park CC-3 Chain Checker for about $7.00 about 10+ years ago. Quick, clean and easy to use...

It's been superseded by the CC-3.2 gauge with .5% and .75% wear indicators rather than .75% and 1.0% on the original checker.

This short video has a lot of good info on chain wear and how these gauges work.


Park also makes a more expensive CC-2 for more critical measurements on 10-11-12 speed chain.

When I lived in NM during the 70's, I changed my chains at ~3000 miles. We imported Sedis and later SedisSport chains on wooden spools of 50 meters or 100 meters and broke them to size. We calculated that they cost us about $3.00 a chain which is what I paid.

I used a dry lube to avoid picking up dust and grit and saved the used chains in plastic Baggies. When I got the Park CC-3, I dug out the box and proceeded to measure them. They ALL checked out OK!

I've used some of them on old bike boom French bikes with 5 speed FWs.

The extended bushing pins pick up the teeth on some of the older freewheels and shift better than modern chains in those situations.






Messing around with rulers trying to measure dirty, greasy old worn out chains was never worth the bother to me!

verktyg "50"

alo

What I do. Have the chain on your largest front sprocket. If it sits down in all of the low points, it is good. If it rides up some of the teeth, it is stretched. Keep this a secret. If people know about it, they will not buy chain tools.

oneclick 

A new (or good) chain on a worn sprocket will not fit. Checking the chain with calipers/chain-checker IS the only way to be sure.

alo

It is easy to replace them, but you need certain tools. Look at videos on Youtube, learn what tools you need, and order the tools first.

You talk about the freewheel and cassette. It is one or the other, and they are different. If the bike shop said it is a freewheel, it probably is, but you may be confusing words. Find out what it is. Then I suggest look online to see what it will cost. If it is a freewheel, it probably not be excessively expensive, unless you want an unusual one. The one you replace it with does not have to have all the same size sprockets, but it needs to fit.

People will tell you, if you don't replace the chain, the freewheel will wear faster. If it is already worn out, does that matter.

With a stretched chain, the front sprockets can also wear. But larger sprockets wear slower.

When it gets too bad, the chain will jump teeth on the sprocket when trying to accelerate quickly, or riding up hill. It will get to the point where you need to replace it if you want to continue riding the bike.

If the chain never jumps teeth, I suggest learn what tools you need, and order them. After you have the tools, decide whether you want to replace things straight away, or ride the bike longer.

I had a stretched chain last year. It was the wet season, and a lot of mud got on it whenever I rode the bike. I decided to wait until after the wet season before replacing the chain and sprocket.

alo

The bike shop has said it is worn out. He does not have the tool to check it himself. This will give him a good indication.

oneclick 

A ruler he doesn't have?

alo

Do you think it would be possible to have a situation where the chain is significantly stretched, yet it sits down in all the low points on the large sprocket, and never jumps teeth on a sprocket while riding?

Andy_K 

I'd check the chains with a ruler and replace as necessary. Chain checker tools are nice for a quick and easy reading, but many, like the Park shown above, can sometimes tell you a chain is worn when it's still OK. Pedro's makes one that is better about that but harder to use. A metal ruler with easy to see lines is a reliable tool for this.

I wouldn't replace the freewheel unless you have some reason to believe it's worn. If your chain is really stretched, there's a chance the freewheel may be. Bike shops will suggest that you replace both together because that makes their work more reliable. They want you to have the best possible experience out the door. If you're doing the maintenance yourself it's usually not necessary. I replace my chains about every 2-3000 miles (sometimes as little as 500 miles depending on the conditions they've been used in), but my cassettes last much longer than that. If you don't have shifting problems, you can look for visible signs of wear on the cogs.

gthomson

Ok so I got the chain checker tool, had a look the chains on my bikes and 3 are fine but my favourite bike, the Peugeot is at 1.0 so it is worn. It doesn't have problems shifting and it doesn't skip on me when riding but then I'm not racing or taking these bikes on long tour rides. Usually for short rides or to the coffee shop.

I have 4 vintage road bikes. Two of them I have upgraded the wheels to 700c, modern wheels which required a cassette and the other two I have left original wheels on which still use a freewheel, hence both systems in my previous comment. Both cassettes I bought used so I guess I was lucky they even worked OK with the existing chains I had.

Is there a recommended chain I should be looking at for older bikes? It sounds like it would be handy to have Verktyg's left over Sedis chains but I guess I will have to find something new.

Sorry for the confusion, the original bike I took to the bike store which was assessed with the worn chain is a newer bike and that will be addressed later. My concern and reason for the post was about my older bikes, and how to keep them running with 30+ year old components. Here's the vintage bike with the worn chain.

SurferRosa

Park chain tool is $18.
Sram pc830 chain is $13.
Park fr1.3 tool is $9.

genejockey 

When all 3 are worn out.

Kabuki12

My only experience with a chain causing a serious problem was when I bought my Medici a while back it came with a racing FW that had "young man gearing" . I changed the FW to something more my speed(pun intended!) . After riding the bike I noticed that even though it shifted perfectly , when I accelerated or powered up a hill there was a grinding feeling in the drive. It was as if there was debris in the bottom bracket. After completely going through the BB and greasing and adjustment , the problem was still there. I went to my LBS and the first thing they checked was the chain, yup , bad! Now I have a gage and check my bike's chains when I lube the chain.

acm

I wouldn't fret too much about the type of chain you use. I've only had a bad experience with a chain once, a no-name cheapo singlespeed chain I bought off amazon for a few dollars at the beginning of the pandemic which eventually failed at the quick link.

Much more important is getting one of the appropriate width (based on the number of rear cogs on your bike) and length (if your old chain didn't give you any trouble, just use the same number of links), in addition to keeping it clean and properly lubricated. I achieve the latter with simple paraffin wax with no additives. It lubricates beautifully and doesn't pick up any dirt, though waxing a chain is admittedly a massive pain in the rear.

If you're looking for a reliable, cheap chain, KMC won't steer you wrong.

John E

For me, the best chain checker is still a ruler. If 24 half-links measure more than 12-1/16", the chain has elongated by 0.5 percent, and it is time to replace it.

verktyg 

Chains don't "stretch", the pins and side plates wear which results in the length increasing (photo courtesy of Sheldon Brown RIP)




This shows the area where the cogs wear.

Here's another type of sprocket wear - "Shark's Tooth" or hooked sprocket teeth.




Chain widths of various manufacturers... Chains are not precision instruments so YMMV!

Inner Width of the links:

Multi speed chains, from 5 to 8 speeds have inner width of 3/32? (2.38 mm).
Multi speed chains from 9 to 12 speeds have inner width of 11/128? (2.18 mm).

Outside width of the links:

5 & 6 speed – 7.8 mm (5/16 in) (all brands)
7 speed – 7.3 mm (9/32 in) (Shimano HG), 7.1 mm (9/32 in) (SRAM, Shimano IG)
8 speed – 7.3 mm (9/32 in) (Shimano HG), 7.1 mm (9/32 in) (SRAM, Shimano IG)
9 speed – 6.6 to 6.8 mm (1/4 to 9/32 in) (all brands)
10 speed - 6.2 mm (1/4 in) (Shimano, Campy), 5.88 mm (7/32 in) (Campy, KMC)

verktyg

randyjawa 

With this in mind, I make sure that my chains get changed frequently. Chains are inexpensive - vintage rings and cogs, not so much!

alo

This is a good picture for those who are not familiar with how chains wear (which is normally talked about as stretch).

You normally can't see this, because it is inside the chain.

alo

Another good picture. When teeth look like that, you need a new freewheel or cassette.

alo

Bike shops want to be accurate, so they use a tool to check chain stretch.

Casual cyclists don't need a tool to measure chain stretch. The front sprocket check is enough.

alo

Maybe there could be a Wikipedia section attached to the forum, and put good information like this in it.