rjones28 

Ha. I guess that is wood? I have an appointment for an eye exam this week.

Daytrip

In my opinion, this tool was designed to sell more chain. It's worse than useless.

The chain in that photograph has more than 2,500 miles on it. It failed the Park Chain Checker Tool test about 1,500 miles ago.

roadiejorge 

I'll keep that in mind for future expensive tool purchases since rarely do they include that kind of adventure.

KiddSisko

A tape measure, which is typically made of a flexible material intended for use by tailors and seamstresses to measure inseams and arm length when making slacks and blouses, would be the worst option for measuring wear on a chain. Staring at the chain and guessing would give you the same results as a tape measure.

blacksquid

+1 - I use and like this and keep it with my bike tools. It has two sides depending on which method you like to use and is easy to measure the chain while it's still on the bike.

Pilsley

Hmmm,

I'm pretty sure he knows what kind of tape measure he was talking about!

coasting 

I have a problem. For both of the last 2 chains I bought, I measured them when newly installed. Both times the 12 inch mark on the ruler was on the left edge of the rivet already. Is my ruler wrong or should I replace the chain immediately before riding?

Daytrip

Quit buying your chains second hand on Ebay, coasting.

And don't buy your rulers at the Dollar Store. Do they have those in England, BTW? The Pound Shoppe, perhaps?

coasting 

we have loads of pound shops now. what we need is a 99p shop when deflation kicks in.

Sprocket Man

I wish I had the benefit of reading this thread before I bought this POS:


Right after I bought this, I checked a chain that had a couple hundred miles on it and the tool told me that it was almost ready to be changed. I was puzzled, so I posted a thread here a couple years ago and was told by several people that the tool is worthless. I now use a metal ruler. Hopefully people get the message before they buy a lousy tool or they change a chain that's perfectly fine.

blacksquid

I'd check the ruler or you method. Or you could just keep replacing the chain until you get one that's not pre-worn.

Daytrip

Kind of scary to think that you're out there driving a car and riding a bike with those eyes, especially since we're basically neighbors.

Shimagnolo

This is the correct answer.
Chain checkers confuse roller wear with chain stretch and exaggerate the reported wear.
The 12" measurement is the right way to do it.
BTW I have a Park chain checker in my tool box, and quit using it.

makeitso5005

I've checked dozens of chains with a similar tool (Nashbar version) and all those that failed had a good amount of stretch in them and should be considered to be replaced. It's true that the tool will possibly measure double the amount of stretch due to it pushing on the rollers of both sides and roller wear isn't really chain wear BUT in terms of ability to do as maintenance it's a really nice tool to have. Takes less than 3 seconds, don't get your hands dirty handling the chain, and once it does say your chain needs replacement, double check with the ruler method and work appropriately. I basically start looking for a chain deal when the 1% mark falls in (and I think many people who say they fail with a new chain don't know what falling in means) and then will replace it when the ruler says it needs it or I feel like it. Since technically the rollers are what contacts the gears, if you have excessive roller wear you're probably wearing the gears as well.

madpogue 

Tape measures are used by roofers, builders, etc. who have to get measurements down to the 1/32" over several tens of feet. They're made of steel, which is flexible in the dimension in which it coils, but not in the dimension in which it is used to measure (it would be pretty useless if it were). If I trust one to measure a $20,000 roof on my house, I would trust it to measure a $25 chain.

(Apologies to our overseas members for the flagrant references to the byzantine units of measure we use here. We'll catch up, one day...)

Accordion

What I've heard about this tool is that the two measurements mean two different things. If the smaller of the two measurements is used and fails then you need to replace the chain. If the larger of the two measurements fails then you have done damage to your drivetrain. Who knows.

Daytrip

The guy with the steel ruler knows.

blacksquid

I thought that only the Shadow knows.

rjones28 

I'm a regular Mr. MaGoo.

Bob Dopolina 

Buy a Park spoke ruler that has both...

Daytrip

Loved it.

Great racial/handicap stereotyping lessons for kids, circa 1965.

For all you kids out there, it was kind of like Spongebob without the gay overtones.

RacerOne

Nice little how to. Thanks.

Carbon Unit

According to my bike mechanic, this is the only chain wear checker, other than a ruler, that works.

https://www.bigringadventure.com/wipp...chain_wear.htm

DaveSSS 

Even the Wipperman chain checker does not truly measure elongation. You can not bear against a roller at each and of the measurement and get true elongation, since the wear on two rollers is added to the measurement and all rollers are not the same diameter. That's why some chain checkers show a brand new chain to have .25% elongation, even though they are usually a little short of .500 inch per link, when brand new.

I made my own full-length measuring tool and found that new chains may be about 1/16" short, over a 53 inch length, when new. I imagine that the first 50-100 miles takes care of that, as all the parts "seat-in" with one another.

Get a 12" precision rule with square ends so you don't have to eyeball any of the graduations.
https://www.use-enco.com/CGI/INSRIT?P...MPXNO=19522213

Lay the rule on the edge on the edge of a pin, so you can see the entire pin. The pin at the opposite end of the rule will be completely covered, when the chain is new. When almost half of the that covered pin is exposed, you've reached .5% elongation.

That works great for chains that elongate quickly, but it's worthless with a Campy chain that can be completely worn out, but only have a fraction of the much elonagation. The rollers can be shot and the side clearance excessive, but the elongation small.

Mr. Fly

And your mechanic will be wrong, since the Wippermann suffers from exactly the same error in measurement as the Park, Rohloff and most other chain wear measurement devices commercially available.

If you can find a Shimano TL-CN40 or TL-CN41 tool, they are accurate in that they measure only pin-to-pin distance and do not obfuscate the matter with roller wear, that obviously is immaterial to the pitch of the chain and varies significantly between even new chains.

See THIS