Last week I was searching through my American Express online statements and my Gmail trying to figure out when I bought my Wippermann Connex 10S0 chain. The reason is that I thought it should be showing wear by now, and I was starting to worry about it.
I worry about all sorts of strange chain-related thins. Is my measuring technique wrong? Is the chain damaging my drivetrain? Am I at risk for another catastrophic failure of the chain during the ride? I needed to answer these questions for my own obsessive-compulsive reasons, and if I could determine when I bought it, I could estimate mileage, which I could then use as another data point in my chain wear assessment.
Unfortunately, American Express doesn't provide easy access to statements that far back, so I have to rely on measuring the chain wear. I religiously maintain my drivetrain, measuring chain "stretch" with a go - no go gauge (shown in the below photo). I bought the gauge last December, and I know I had my current chain before that. I bought my Garmin Edge 305 in October 2008, and I had the chain before then too. Since October, I've ridden over 1500 miles. So, the chain has at least 1500 miles on it, and probably more like 2000-2500 miles. I measure it every time I clean the drivetrain, and have not seen any wear...until last Friday.
On Friday night, while cleaning my bike and drivetrain in preparation for Saturday's ride, I measured the chain stretch. Surprisingly, the 0.75% side DID engage in several places, but the 1.00% side did not. The chain is finally showing some wear! It felt a little odd, but I was actually happy that the chain was showing measurable wear. Otherwise, I would continue to question whether the Spin Doctor gauge was made to specification and was actually measuring correctly.
As I mentioned, I probably have over 2000 miles on the chain. Based on a little internet research, this seems fairly typical. The chain doesn't absolutely need to be replaced at 0.75% stretch, but it does absolutely need to be replaced at 1.00% stretch. Since I want to keep turning smoothly, and I have a spare chain on the shelf, I'll install it next time I clean the drivetrain.
I guess I'll have to find another source of worry. Unseen cracks in my carbon frame are near the top of the list!
5 comments:
Not that I'd ever need to remind you, but for your reader's sake, I think it's wise to point out that if your chain is completely worn, it's recommended to replace both your chain and cassette together since they typically wear at the same rate.
Now if you catch it early like you have, then it's okay to just swap out chains.
Thanks for this blog on chains. I've wondered the same thing about how long a chain should last. Now I know how to tell!
Anonymous, actually, if you replace your chain when it's showing 1% wear or less, there's no need to replace the cassette. They don't wear at the same rate at all--cassettes last much longer. Unless you're not replacing your chain when you should, in which case the worn chain wears the cassette teeth along with your chainrings.
My current Dura Ace chain has over 4000 miles on it and is not even showing .75% worn. My brother's on the other hand, just broke after only 1500 miles and was over 1% worn. He was shocked it would wear this fast and hadn't even checked it. I'm at a loss to explain the differences in wear and the only thing I can come up with is lube.
@Ski Bike Junkie -- What lube do you use, and what about your brother? I use Rock n Roll Absolute Dry. Just curious...
It is rather interesting for me to read this post. Thanx for it. I like such topics and anything connected to them. I definitely want to read more soon.
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