Number of gears is one consideration, the other is Chain Wrap.

The Cyclone MKII should work fine on a 5 speed and should probably work on anything up to an 8 speed.

The other consideration is chain wrap. you'll need your Cyclone to have a long enough cage to handle the gear range you've got. Calculate it like this: (Big Ring + Big Cog) - (Little Ring + Little Cog). So count all the teeth on those 4 gears, and do the math. The number you end up with is the amount of "Chain Wrap" you need your derailleur to handle. The more capacity you need, the bigger the cage you need on the RD. A long GT cage might handle 40+ teeth, while a short racing cage might only handle half that as its meant for a corncob cassette.