Bicycle Mechanics - How often should cassettes be replaced?

yesterday I went to ride, pedalled about 10 feet and the chain came off, I put it back on, and tried again, same thing, I figured out the whole cassette was loose, I took it too my LBS this morning and he replaced it, he said the freewheel was finished, so I was wondering how often should I replace the cassette?

yesterday I went to ride, pedalled about 10 feet and the chain came off, I put it back on, and tried again, same thing, I figured out the whole cassette was loose, I took it too my LBS this morning and he replaced it, he said the freewheel was finished, so I was wondering how often should I replace the cassette?


A lot depends on how it's used. In general, mountain biking is harder on cassettes than road biking due to the increased introduction of dirt and crud into the body. If it's spinning freely, I wouldn't worry. Once a year or so, squirt some Tri-Flow or other light lube into the internal mechanism, more often if you ride in a lot of rain and/or dirt. I've never had to replace one (I road bike) and when I owned my bike shop, most of the cassettes we replaced were on mountain bikes used in a lot rain/mud and most commonly on bikes that had been left outside to "age" (i.e. rust) resulting in frozen internal mechanisms. I was always amazed at how much punishment cassette bodies (Shimano, not Suntour) could take before they died.

My 2004 Trek 4300 with 2000 miles on it just got diagnosed with needing a new cassette. I think that is not very many miles but have to agree that i see shark fins. I sure thought they would last longer than that.

BTW, mine is just worn on two cogs, the gears that i obviously use the most. That is another element. The gears you never use will last forever.

My 2004 Trek 4300 with 2000 miles on it just got diagnosed with needing a new cassette. I think that is not very many miles but have to agree that i see shark fins. I sure thought they would last longer than that.

BTW, mine is just worn on two cogs, the gears that i obviously use the most. That is another element. The gears you never use will last forever.

My post refers only to the freewheel body, not the cogs...

Crazy...you mention cassette and freewheel in your post. You do realize they are different. How often do they get replaced? As often as they fail.....(not very)

Crazy...you mention cassette and freewheel in your post. You do realize they are different. How often do they get replaced? As often as they fail.....(not very)

Now you've got me started...but in a good way

Yeah, you're right about my mixing terms..some habits die hard. I started cycling before cassettes were invented, when freewheels ruled the earth. Like the old style Regina Oro that took the touch of a brain surgeon lest you ripped the poorly designed slots that the freewheel puller inserted into. Also, during the age of the freewheel (Cogassic Age when Merckxasaurus Rex was King!) many suffered bent rear axles (lots of them were Campy Records) since so much of it was unsupported on the drive side. Then the cassettes appeared, a much improved result of the industrious tool using Shimano tribe. Do I miss the old technology? Not a bit! When the history of cycling technology is finally written by a non-Italian;with the invention of the cassette, index shifting, and linear response road brakes, it will be ever so obvious that the quantum leaps in bicycle component technology came from the East.

Here's a little story: when Mike Sinyard, founder and Pres. of Specialized spec' the first production bike, the Stumpjumper, many mountain bike parts were not yet invented. The Tommaselli brake levers came from motorcycles, the crankset was a french T.A. Cyclotouriste with a jillion bolts holding the rings together. Mike went to Italy and said to Campagnolo: "Hey guys, you're the gold standard, the creme de la creme of bike parts. This mountain bike thing is gonna be a big deal. Howzabout designing some parts for these rigs and making a few lira to boot?" The collective heads of Campy sniffed the rarified air of Vicenza and basically said the mountain bike was a dead end on the family tree of cycling. Mike then went to Japan, talked to a few folks over there that sensed the Euro complacency and the rest is history. By the time Campy got started on making a mountain bike gruppo, they were so far behind the curve that they never ever succeeded in making commercially successful mountain bike parts. The mountain bike, in fact pushed cycling technology because of it's popularity. With a big market came the big changes in drivetrain technology and Shimano invented the most important ones, the cassette included.

I feel better now..

I've replaced all my cassettes with CDs by now.

I've replaced all my cassettes with CDs by now.


Were CD's invented by Campy?

Were CD's invented by Campy?

I thought they were invented by financial institutions and banks. :)

I thought they were invented by financial institutions and banks. :)

Yikes, great reply...I'm a financial advisor, I should know that!

when the teeth start to look pointed rather than squared, that is a good sign to replace it.