Slowing down hill!!!

[aicabsolut]

The cassette shouldn't keep spinning after you start freewheeling. It's the whole wheel that should keep going for a while after you stop pedaling with the rear wheel off the ground.

If it still comes to a stop quickly, then get your freehub serviced and/or replaced asap.

Worst case scenario is rebuilding or replacing the wheel. Continuing to ride with a dead freehub could cause some damage that will make a new one not mesh properly with the rest of the hub, so get that checked out!

Oh, and I recently found this out the hard way: If you get a freehub overhaul, check to make sure the wheel is dished properly afterwards. This means that the wheel still sits centered between the chainstays. Sometimes, a freehub replacement will mean that the wheel needs to be redished. My LBS didn't catch this, and I came close to trashing my frame with a wheel that would rub a chainstay. I had to pay to get it redished. Then I read on SheldonBrown that it probably needed redished when they worked on the freehub to begin with.