Ultegra Cassette lasts 25,000 miles

Cassettes wear out eventually. Small cogs go first.

Inquiring minds want to know: How long will my freewheel cassette last? How about 25,000 miles?

That’s what I got from my Ultegra 6700. Here are some caveats:

1. Cleaned the chain regularly, like every 500 miles.

2. Rode mostly on pavement, only about 2 percent off-road.

3. Replaced the chains between 0.5 and 0.75 on the Park chain-wear measurement tool.

So how do you know when your cassette sprockets are worn? The chain skips or catches sometimes; you feel the occasional slip when starting up. Note that when a chain is worn, front chainwheel shifting degrades.

Track your miles. I can’t imagine a cassette lasting more miles than what I got from mine.

Once again, I got about 6,500 miles [WRONG. I SWITCH CHAINS. I GOT ABOUT 3,500 MILES] from Ultegra 6600/6701 chains. I could not detect any difference between the models in terms of longevity or shifting.

Unless you break a sprocket, I wouldn’t bother trying to save money by swapping out the smaller or worn cogs. I replaced only the sprockets, not the body. It’s running smoothly.

Finally, my Ultegra brake pads lasted about 25,000 miles as well. I moved the back to the front to extend life. I still have the originals on the back, so more than 25,000 miles with careful management. Of course, I ride where there are a lot of hills, so these pads could last longer.