A Chain Wear Indicator Is Your Friend

Park Tool Chain Wear Indicator CC-3.2

Park Tool Chain Wear Indicator CC-3.2


A year ago, I bought a new hybrid bicycle. It’s hard to believe that an entire year has gone by. And, it’s even harder to believe how many miles I’ve traveled on this bike; by the end of the month, it will have been ridden over 6,000 miles.

Overall, the bike has held up well. It still looks new and the components are in good condition. But, as someone who has been riding older classic bikes, with old world quality, I was surprised by how fragile some of the newer parts were. In particular, I’m referring to the chain.

My ‘90s road racing bike’s chain has lasted for tens of thousands of miles. Heavy gauge chains of this sort are no longer manufactured. Today, everything is made with the goal of reducing weight in mind, resulting in lower quality and less durability. Reduced weight comes with a price — reduced longevity.

Like most bikes today, my hybrid came with a 9-speed chain. Since my bike was going to be used for transportation and utility, the absence of a 10-speed chain was a stroke of luck. 10 and 11-speed chains are more fragile. As a bike with road racing geometry, it wouldn’t have been unheard of for the manufacturer to equip it with a 10-speed drivetrain.

My hybrid was purchased in December because I needed a new transportation bike right away. I couldn’t wait until the cycling season. The bike’s infancy was spent in one of the harshest, snowiest winters in recent memory, and while the bike held its own, its components took a beating.

Overall, the components held up well, but one part in particular failed: the chain. I kept it as clean as possible, and lubed it on a daily basis — but this wasn’t enough. Before I knew it, the shifting started to get sloppy. I delayed replacing the chain because I thought I could postpone it. I put it on my to-do list, and while I was waiting for a chain I ordered online to arrive, the chain started skipping.

Skipping, in chain terminology, is the kiss of death. Once you’ve reached this point, you’ve reached the point of no return.

Rather than waiting for the new chain to arrive, I took my bike to a local bike shop. Their chain selection would be smaller and their prices higher than online, but I couldn’t wait any longer. It had become a bona fide emergency.

At the shop, I asked them to take a look at the shifting because it had gotten a little too sloppy for my tastes. The derailleurs were adjusted and working properly, as far as I could tell. So, the culprit seemed to be the worn out chain.

The mechanic looked at the bike and said “How many miles does this bike have on it?” I didn’t have a computer or GPS on the bike at that time, but I did have a pretty good idea how far I’d ridden each day. The bike had approximately 3,500 miles on it.

“Your chain is really shot,” he told me, shaking his head admonishingly. It should have been replaced by now. This guy had no idea how many other things I’d had to do, and how much I needed the bike. While it’s true that I could have had an extra chain on hand, it’s equally true that my older bikes’ chains had lasted for years. My hybrid was far less than a year old. Surely, it couldn’t be that bad.

Well, it was. The chain had worn beyond what is recommended by the manufacturer for replacement and it had begun to cause wear on the sprockets. When both a chain and a sprocket are new, every roller that is in contact with the sprocket presses equally against the corresponding tooth of the sprocket. After the chain and sprocket have begun to wear, this is no longer true. People refer to the resulting phenomenon as “chain stretch,” the point at which the chain no longer matches the original pitch of the sprocket.

At this stage, a bicycle owner faces a dilemma. It is possible to replace the chain and continue riding the bike. However, the chain won’t work well due to the difference in wear between it and the sprockets and the chainrings. This scenario may cause accelerated wear on the sprockets and chainrings, which will have to be replaced.

Some cyclists take a chance and just replace the chain. Others replace the chain and the cogset, the theory being that it will cause less wear on the chainrings  —  assuming that they haven’t worn to the point of needing replacement.

I wasn’t keen on the idea of having to replace the cogset, but at this point, there was little wear on the chainrings. I might come out ahead, in terms of the total number of parts replaced over a given amount of time, if I sprung for the new chain and cogset. Knowing this, I bit the bullet and replaced both.

The mechanic asked me whether I had measured the chain recently. Actually, I hadn’t. But, when I saw the result of procrastinating, I wished that I had.

The mechanic pulled out his trusty chain checker tool and asked me if I owned one. No, I didn’t. He had the professional model, which he recommended, but which was costly for someone who only needed to check one or two chains. There were other, less expensive models, he assured me. And, I silently vowed to research this subject upon returning home that day.

Once home with my new chain and cogset, I compared several brands of chain wear tools. The one I settled on, Park Tool’s Chain Wear Indicator CC-3.2, was a good balance of quality, ease of use and cost. Park Tool still makes their products in the USA — and it shows in the quality. I bought one for under $10.

The CC-3.2 is a “go-no go” gauge designed to accurately indicate when a chain reaches .5% and .75%. Chain manufacturers recommend replacing your chain at one or the other of these points.

The tool is easy to use and essentially foolproof. I’d recommend such a tool to anyone, but particularly to those who live in harsh climates where salt and sand on winter roads may accelerate the wear on a chain and drivetrain.

In fact, after I thought about it, I realized that the reason my chain went downhill so fast was the amount of salt and sand used on the road where I live. It’s like going out onto a beach each time I take a ride. Wetness from the road and chain lube cause sand and salt to adhere to the drivetrain where they grind down the metal.

In addition to using a chain wear indicator tool, keeping a chain clean and well lubed is a good way to prolong its life. People vary in how much mileage they get out of a chain. Some cyclists replace a chain every 1,000 miles, but 2,000 miles seems to be closer to the norm.

Measuring a chain regularly takes the guesswork out of understanding when to replace a chain. To avoid premature wear of the sprockets and chainrings, keep a spare chain on hand and replace the old one as soon as it reaches the point where the manufacturer recommends replacing it. In hindsight, this is what I should have done.

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