What size are you running?I have the Yakima Skybox on my 25 classic. Don't buy new, there are a bunch on craigslist at around 100 bucks. It swallows up foldable chairs, fenders and all the canvas pieces. don't worry if you get one with now key... there is a guy on eBay that will sell you the install key which removes the core and then give him the core# and then get the right key for 5 b bucks .
It clamps on tight and I have mine on the starboard side to balance out some of the weight.