What are the benefits to running a cassette hub over a freewheel hub?
There are a few reasons to run a cassette hub over a freewheel hub. One reason is the ease of changing rear sprockets. With a freewheel hub you have to have multiple freewheels and sometimes freewheel tools. A freewheel can be very difficult to remove depending on how long it has been installed. On a cassette hub you have cogs that are changed. Most cassette hubs come with multiple sizes of cogs. The tools to remove the cog from your cassette hub are the same for all cogs as long as you are using the same cassette hub. The next reason is reliability. Freewheels go bad over time. Once a freewheel goes bad you have to throw it away and buy a new one. On a cassette hub, the freewheel mechanism is built into the hub and is called a driver. If the driver goes bad it is completely rebuildable. With a cassette hub you have the ability to run very small gearing in the rear. Currently with a cassette hub you can run as small as an 8t cog. The smallest a freewheel hub can go is 13t.
