I bought a Frankenbike off Craigslist.
It's a Specialized Rockhopper of unknown year, converted to a commuter, with shocks up front and V-brakes.
I love this weird little bike and want to put a Copenhagen wheel on it when they come out, to make it into the ultimate commuter frankenbike.
To install the wheel I'll need to know whether I'm dealing with a freewheel or a cassette. How can I find out without taking the bike apart or knowing the year it was built?