A customer's worn-out chainring in Denver made me rethink my whole approach to wear limits

I was working at a shop in Denver about 6 months ago, and a guy brought in his gravel bike with a skipping chain. I pulled out my chain checker, and it read 0.75%, which I figured was fine. I told him the chain was okay but the cassette might be worn. He insisted I look closer at the big chainring. Sure enough, the teeth were completely hooked, like little shark fins. I'd always gone by the chain wear number as the main indicator. This bike had a relatively new chain but a totally shot ring from grinding through mud and grit. It made me realize I was putting too much faith in one tool. Now I always do a visual check on the rings no matter what the gauge says. Has anyone else had a case where the chain measurement lied to you?

2 comments

2 Comments

betht198d ago

Ever check a chain on a single speed or fixie? Those things can stretch a chain like crazy but the ring teeth often look fine because the load is so constant. It's the opposite problem, the tool says replace but the metal isn't shark-toothed yet. Makes you realize wear happens totally different based on how the bike gets used.

paulhernandez8d ago

That's a solid point about single speeds. Chain checkers just measure one kind of wear. I've seen rings get sharp from cross-chaining long before the chain stretches out. Gotta look at the whole picture.