[rocco]

Does anyone know how to best use a Park CC-2 chain checker? I'm wondering how hard to press for a reasonably accurate reading. I know not to press so hard that the pins get bent but it's possible to not bend them and still get a very wide range of readings. Perhaps I should squeeze/press and release but I'm sure if that's accurate or not.

 

[Kerry Irons]

It's easy.

Does anyone know how to best use a Park CC-2 chain checker? I'm wondering how hard to press for a reasonably accurate reading. I know not to press so hard that the pins get bent but it's possible to not bend them and still get a very wide range of readings. Perhaps I should squeeze/press and release but I'm sure if that's accurate or not.

Simply put the Park unit on the workbench, take out a decent ruler, and measure your chain for wear. The chain checker is not a very accurate tool, and it measures the wrong thing (bushing to bushing distance). IME the Park tool is not worth the effort to try to use it when a ruler works so well and easily, plus the ruler gives you good information.

 

[Thorn Bait]

I agree the ruler is better - but for the chain checker I have found you have to stop pressing the moment you meet resistance. I find otherwise it makes you change chains a lot more often. Even then it doesn't do as well as the ruler.

 

[Chainstay]

Can you elaborate?

Simply put the Park unit on the workbench, take out a decent ruler, and measure your chain for wear. The chain checker is not a very accurate tool, and it measures the wrong thing (bushing to bushing distance). IME the Park tool is not worth the effort to try to use it when a ruler works so well and easily, plus the ruler gives you good information.

What standard do you use? How much stretch is too much? Isn't bushing to bushing distance the cause of excessive wear on cogs?

I use the chain checker and compare it to a new chain. A new chain comes in at about .25 and I will replace a chain that is up over .75

 

[Juanmoretime]

I also use a chain checker, I do own a machinist ruler too. I've replaced by chains when they get to slightly past .5 on the scale and that is usually around three thousand miles. I mostly use the chain checker and have one Campy Record ti/steel cassette with over 10,000 miles on it and still going strong. It may not be as accurate but getting that kind of mileage out of a cassette is fine by me. I also realize I may be replacing my chains prematurely but for the cassette life I'm getting I won't complain.

 

[C-40]

how to measure..

First, clean the chain. Lay the chain on a bench, on its side and pull it tight. Place an accurate 12” scale on the edge of a pin. The pin at the opposite end will be totally covered when the chain is new. As the chain wears, this pins will begin to “peak out” from under the scale. Change the chain before ½ of this pin is exposed. The maximum allowable wear is 1/16” (.063”) per foot or 5%. One half of a pin is slightly more (.070 inch).

This measurement can also be done on the bike, holding the scale along the lower section of chain, but it’s a bit tougher to do.

Wear on the rollers is NOT what causes a problem, it's the wear between the pins and the bushings formed into the inner sideplates that increases the chain pitch (center to center distance between the rollers).

 

[rocco]

Everybody is a wise guy...

Simply put the Park unit on the workbench, take out a decent ruler, and measure your chain for wear. The chain checker is not a very accurate tool, and it measures the wrong thing (bushing to bushing distance). IME the Park tool is not worth the effort to try to use it when a ruler works so well and easily, plus the ruler gives you good information.

LOL... With all due respect, thanks for the sarcatic "simply put the Park unit on the workbench" and the lesson about the ruler but I already knew all of this 20+ years ago. Except it's roller to roller not bushing to bushing; modern chains don't have bushings.

I don't think the Park tool is useless if it's used regularly as a quick gauge and if one measures the chain with a steel ruler every so often. I get at least 10,000 miles out of my Campy chains and 40,000 miles out my cassette because keep them cleaned and lubed and I don't use bad gearing choices/chain line cross. The fact that I monitor wear frequently also helps and having quick gauge aids this approach IMO. You may not agree but why not just answer the original question if you can?

 

[rocco]

I also use a chain checker, I do own a machinist ruler too. I've replaced by chains when they get to slightly past .5 on the scale and that is usually around three thousand miles. I mostly use the chain checker and have one Campy Record ti/steel cassette with over 10,000 miles on it and still going strong. It may not be as accurate but getting that kind of mileage out of a cassette is fine by me. I also realize I may be replacing my chains prematurely but for the cassette life I'm getting I won't complain.

Exactly... The same deal over here and IMO having a quick gauge to use frequently in addition to using the steel ruler every so often helps max out drive chain components.

 

[rocco]

Since we've digressed off the original question...

First, clean the chain. Lay the chain on a bench, on its side and pull it tight. Place an accurate 12” scale on the edge of a pin. The pin at the opposite end will be totally covered when the chain is new. As the chain wears, this pins will begin to “peak out” from under the scale. Change the chain before ½ of this pin is exposed. The maximum allowable wear is 1/16” (.063”) per foot or 5%. One half of a pin is slightly more (.070 inch).

This measurement can also be done on the bike, holding the scale along the lower section of chain, but it’s a bit tougher to do.

Wear on the rollers is NOT what causes a problem, it's the wear between the pins and the bushings formed into the inner sideplates that increases the chain pitch (center to center distance between the rollers).

With all due respect, that's all correct but virtually every modern chain and certainly every Campy and Shimano is the "Sedis" bushingless design.

Taking the chain off and laying it on a bench to measure it with a metal ruler is best because measuring it accurately isn't nessarily a quick and easy thing to do when .063 is the critical wear point. However, taking a Campagnolo chain off to measure it frequently or even infrequently isn't an option because I don't think using a Wippermann Connex link or a Craig Super Link is such a great idea IME & IMO. This is why I think using a quick gauge such as the Park CC-2 chain checker to it's max potential frequently is useful in this context as long as one uses a metal ruler very diligently once in a while.

 

[divve]

How do you think a chain bends? You can call it a link, hinge, or whatever, but in the end the inner plates and pin still function as a bushing.

 

[rocco]

That's is true in that the plate is 3-dimensionally shaped and it acts as bushing but there aren't specific or separate bushings. It's plates, pins and rollers. They all wear with use and abuse to varying degrees which adds up to an elongated chain.

Let me restate the OQ.... How does one best utilized a Park CC-2 chain checker for what it's worth as a quick gauge of chain wear?

 

[Jesse D Smith]

Since he's already has a webpage http://sheldonbrown.com/chains.html dedicated to the topic, I'll provide Sheldon's opinion in place of my own.
"The major cause of chain "stretch" is wearing away of the metal where the rivet rotates inside of the bushing (or the "bushing" part of the inside plate) as the chain links flex and straighten as the chain goes onto and off of the sprockets. If you take apart an old, worn out chain, you can easily see the little notches worn into the sides of the rivets by the inside edges of the bushings. With bushingless chains, the inside edge of the side plate hole that rubs against the rivet has a smooth radius instead of a sharp corner. This probably contributes to the greater durability of bushingless chains."

 

[Keeping up with Junior]

Multi Tool

...I don't think the Park tool is useless if it's used regularly as a quick gauge and if one measures the chain with a steel ruler every so often...

The quick check is important. With three riders and a dozen bikes hanging in dark corners of the basement using a ruler for a quick check of chain status would be quite an ordeal and would not happen as often as it should. With the chain checker I can check all dozen chains without moving any bikes or removing any chains. Keep in mind using a ruler in a dark corner of my basement while I am looking at it upside down is just as likely to result in an errant reading. Less frequently or when the chain checker starts to show wear I will use the ruler approach.

As for the original post I would say not very much pressure. Maybe compare to how much pressure it takes to open a metal pop can top.

 

[C-40]

talk about digression...

Every modern chain has a bushing, but as I correctly steated, it's formed into the side plates. Chains haven't had separate bushings for over 20 years.

http://www.sheldonbrown.com/chains.html

The advice you've been given is dead serious. The Park tool is pretty much crap. I have one decorating the bottom of my tool box. A nice 12" machinist scale can even be used on the bike with more accuracy than a Park chain checker.

You shouldn't have to monitor wear frequently. With really good maintenance, a chain won't reach 1/16 inch per foot elongation for 10-20,000 miles. I might check mine every 2000 miles, but I keep getting the same answer, almost no measureable elongation, even after 5500 miles, my chain shows about 1/16" over four feet.

 

[rocco]

Every modern chain has a bushing, but as I correctly steated, it's formed into the side plates. Chains haven't had separate bushings for over 20 years.

http://www.sheldonbrown.com/chains.html

The advice you've been given is dead serious. The Park tool is pretty much crap. I have one decorating the bottom of my tool box. A nice 12" machinist scale can even be used on the bike with more accuracy than a Park chain checker.

You shouldn't have to monitor wear frequently. With really good maintenance, a chain won't reach 1/16 inch per foot elongation for 10-20,000 miles. I might check mine every 2000 miles, but I keep getting the same answer, almost no measureable elongation, even after 5500 miles, my chain shows about 1/16" over four feet.

Thanks but your not really telling me anything I don't already know. Zero actually... I didn't ask for the history of modern chains nor for opinions about the gauge. However, again, that is true in that the plate is 3-dimensionally shaped and it acts as bushing but there aren't specific or separate bushings. It's plates, pins and rollers. They all wear with use and abuse to varying degrees which adds up to an elongated chain.

 

[rocco]

The quick check is important. With three riders and a dozen bikes hanging in dark corners of the basement using a ruler for a quick check of chain status would be quite an ordeal and would not happen as often as it should. With the chain checker I can check all dozen chains without moving any bikes or removing any chains. Keep in mind using a ruler in a dark corner of my basement while I am looking at it upside down is just as likely to result in an errant reading. Less frequently or when the chain checker starts to show wear I will use the ruler approach.

Precisely.

As for the original post I would say not very much pressure. Maybe compare to how much pressure it takes to open a metal pop can top.

Thank you for answering my question, I appreciate it.

 

[Kerry Irons]

Simple to do

What standard do you use? How much stretch is too much? Isn't bushing to bushing distance the cause of excessive wear on cogs?

I use the chain checker and compare it to a new chain. A new chain comes in at about .25 and I will replace a chain that is up over .75

Campagnolo's recommendation for chain replacement is 0.5% elongation, and that means 1/16" in 24 links (12"). IME, there is no reason to remove the chain from the bike. After the weekly clean/lube, I just lay a ruler along the lower chain run and can easily see how much elongation there is. The tension applied by the derailleur is enough to get an accurate reading.

 

[rocco]

I agree the ruler is better - but for the chain checker I have found you have to stop pressing the moment you meet resistance. I find otherwise it makes you change chains a lot more often. Even then it doesn't do as well as the ruler.

Yeah I agree but for it's worth I think it has some utility which perhaps you may agree with.
Being conservative and changing chains more often isn't such a bad thing. The cost won't kill me. Thanks for your answer and thoughts. I appreciate it.

 

[Al1943]

I use both, steel ruler and Park chain checker. After getting a feel for the chain checker I now get consistant results between the two measurements. I trust the ruler more but find the chain checker to be useful.

With the chain checker just take all of the slack out.

With either method it's best to check various parts of the chain, they don't always wear evenly around the full length.

Al

 

[divve]

If you prefer to use a chain checker, get one without moving parts such as the Rohloff Caliber 2. They may not be as accurate as measuring 12", but get the job done well enough and without much ambiguity (the checker will either fall between the links or not).