Chainring Wear and I Don't Care

After eight years and thousands of miles, I finally replaced my commuter's chainring. This is what the teeth look like:

 

Years of hard riding on the same worn-out chain causes excessive friction, which leads the high-grade aluminum teeth of the chainring to squish out. This is also known as "mechanical fretting."

You can see the wear affects the teeth asymmetrically. The side that drives the chain gets most of the punishment, but the other side shows signs of fretting too. 

Here's the worn chainring compared to a new, stainless steel chainring.

Lil bit of lens flair for style.

This last snap of the old chainring on top of the new one shows exactly how much material has worn down over time.

So, when you think your chainring might be worn out, use these images as a guide. If you see the little mushroom snares on the chain-side of the teeth, that's your sign.

As a bonus, here's a super duper worn out chainring from the shop:

This chainring is made of cheaper aluminum than the one I used. Also, I believe the rider used a 1/2x1/8 BMX chain instead of the 1/2x3/32 chain the ring is made for. The wider BMX chain slops around and quickens the wear process. The reason wear is on both sides of the chainring is because at some point the rider turned his chainring around to even-out the wear on both sides of the teeth.

Here's a link to buy a nice Surly Chainring like mine.