Berylbite

What kind of chainwear gauge do you suggest? I've seen different types and I'm curious to hear what the consensus of all you pro mechanics is.

Note: I'm fond of Park Tools.

Dan Burkhart 

I have Park gauges, and have had a Rohloff gauge, but this is what I generally find more reliable.

pdlamb

15" metal ruler or measuring tape, so you can measure from inch mark to inch mark 12" further.

The Park tool isn't too bad, if you've got a filthy chain and no rubber gloves. Change as soon as the gauge drops on the short end; you'll have to replace the cassette, too, if the big end drops.

fietsbob

There is one at the shop, [Pro Link] it has a J curved end that is progressively longer
asit slides into the chain, and so it pulls the chain a bit ..

I have an older Park one, it has a pin on an eccentric wheel
to do similar a wear range , with a red zone, saying 'it's time to replace'

edit, to below , that's the one !

zukahn1 

Is this the one you mean fietsbob, the Progold it is the one a lot of shops use.

bkaapcke

+1 on progold. bk

MudPie

I have a Park one, but tend to rely on a good stainless steel ruler. I usually hang my chain from a nail on a post and measure it with a ruler.

This article analyzes various gauges, and concludes the Shimano version is the only accurate gauge, mainly because of the way it measures. https://pardo.net/bike/pic/fail-004/000.html

ezdoesit

+1 on the metal ruler.

davidad

I have a Rohloff for a quick check, but there is no sustitute for a ruler. There is no accurate way to measure roller wear and it is not a factor in chain life.
I hang mine in the garage after I clean it and measure with an 8' tape. 1/4" in 4' is replacement time.

danacf

My homemadetool from a spoke, and you don’t need an accurate ruler to make one. File a nice 90 bend where the head is and cutit roughly at 12 1/8 or so. Using a newchain, on the bike or not, put it underslight tension an file the spoke down so it overlaps the roller 1/16 of an inchat the 12 inch point. You now have anaccurate 12 1/16” gauge. When the end ofthe spoke no longer overlaps the roller, replace the chain.

HillRider

I have the Park CC-3 chain checker and it corresponds fairly well with the 12" ruler measurement but the ruler is the final arbiter of chain wear.

ThermionicScott 

+1 for good rulers.

DaveSSS 

Precsion rules will measure elongation properly. Most chain checkers add roller wear to elongation and do NOt give accurate results for elongation. Due to variation between brands, a Shimano chanin may check as having .25% elongation when new, but it does not.

pdlamb

I've never understood the "rollers may flop" reasoning. Aren't the rollers the part that will contact the cogs?

ThermionicScott 

Yes, but only when they are spread out from stretch do they wear the sides of the gear teeth.

davidad

There is no way to measure roller wear and it is not a factor in chain life.

DiabloScott

I use the Park thing... I recognize that it may sometimes indicate replacment when it's still a little early, but:

1. It's easier to use than a ruler (really!)
2. You can take the measurement while the bike's hanging on a rack or where it's too dark to see, then read the number where the light's better... with your bifocals on.
3. You can always use it as a quickie check since it will always read a bit higher than a ruler would, and if you're averse to changing a chain before its time - check again with the ruler afterwards.

Jed19

+1 on Park cheap tool and ruler. I bought a nice steel 15inch ruler from Office Depot for about three bucks or so. I like the longer ruler, b/cos of the fact that it extends past 12inches.

The Park tool for a go/no go perspective, the ruler as confirmation.

DaveSSS 

Roller wear can be measured easily. All you need is some calipers with internal measuring tips. When new, the space between the rollers will be about .200 inch for a Campy chain and as much as .210-.215 inch for most other brands. Wear occurs on the roller OD, ID and the bushing formed into the inner side plates. If you measure a worn chain, the space between the rollers will increase from a combination of the wear on all three surfaces. I've used Campy 10 chains for 6,000 miles and measured as little as .15% elongation, but the roller spacing had increased by about .040 inch to .240. The side clearance was also about .013 inch, which is twice that of a new chain. That chain was totally shot, despite having little elongation. When a new chain was installed, I got chain skip on my most-used cog and that was the only chain ever used with the cassette. You can get significant cog wear, even using a chain with little elongation, but severly worn rollers.

Most other brands will elongation much more rapidly, so the elongation becomes too great before the roller are shot. Not so with a Campy chain.

davidad

[QUOTE=DaveSSS;13718448]Roller wear can be measured easily. All you need is some calipers with internal measuring tips. When new, the space between the rollers will be about .200 inch for a Campy chain and as much as .210-.215 inch for most other brands. Wear occurs on the roller OD, ID and the bushing formed into the inner side plates. If you measure a worn chain, the space between the rollers will increase from a combination of the wear on all three surfaces. I've used Campy 10 chains for 6,000 miles and measured as little as .15% elongation, but the roller spacing had increased by about .040 inch to .240. The side clearance was also about .013 inch, which is twice that of a new chain. That chain was totally shot, despite having little elongation. When a new chain was installed, I got chain skip on my most-used cog and that was the only chain ever used with the cassette. You can get significant cog wear, even using a chain with little elongation, but severly worn rollers.

Most other brands will elongation much more rapidly, so the elongation becomes too great before the roller are shot. Not so with a Campy chain.

What is the difference in material used in the campy chains that makes them last so long.

I run KMC chains or whatever is cheapest and do a good job of maintaining them. My bikes each have over 12k miles on their chains and still show less than the 1/16" wear. I have cogs on the tourer with over 30k miles on them.

rydabent

I have a Park CC-3 chain wear tool. I use it as a quick check. I also have a 12 steel mechanics ruler. They pretty much agree.

DaveSSS 

Answers and comments. I have know idea what type of steel Campy uses for the pins and side plates of their chains, but I've used Campy chains since 1995 and the lack of elongation is a well documented fact.

Anyone claiming 10,000+ miles on a chain is not talking about a modern 10 speed chain. I'm a light rider (135-140), and lube my chain every 50-100 miles, plus regular cleanings. I can get a Shimano or KMC chain to show 1/16" per foot elongation in 3500-4000 miles, measured properly with a full length measurement, not a 12" rule or a chain checker. Most people using a chain checker don't get that much because the chain checker produces exaggerated readings. Many of them will show a new Shimano or KMC chain to have .25% elongation even though the true amount is zero. What's it's measuring is the larger roller spacing of the chain.

john hawrylak

I think the bottom scale on Dan Burkhart's 12" ruler in reply #1, the scale in 1/6 of an inch, is used. If the chain is past the hash mark to the right of '72', the chain is elongated 1/12" (1/2 distance between 72 and 73) or 0.69%, compared to the typical 0.75% limit for alloy rings.

The normal 1" scale (top of ruler) does not go past 12", so you either guess at 1.4/16" elongation or you make a mark after the 12".

FBinNY 

While precision rulers are nice, even they are overkill. For chain measuring even the cheap plastic rulers sold for grade school are accurate enough. The only caveat it that if they aren't slightly over 12" overall, so the 0 and 12" marks are in from the end, then they should be used from 1/2" to 11-1/2" (11" length) so you have clean easy to read markings.

DaveSSS 

The best rule to use for chain chain checking is a 12" machinist's rule. The entire rule is exactly 12" long, with no extra material at the ends. Place the end on the edge of a pin and the pin at the opposite end will be completely covered, when the chain is new. When almost 1/2 of that covered pin is exposed, you've reached .5% elongation.

https://www.generaltools.com/1216--PR...E_p_1528.html#

When I did some chain wear testing, I made my own full-length measure device with a tight fitting fixed pin at one and and a precision rule mounted with it's center at 53 inches from the center of the pin. Checking the overall length substantially improves precision.