What that guy just said. There is an "approved bike box size." I don't know if it varies among shippers, but a 1 inch difference can cause the price to double or triple. If you're not sure on the size, call and give them the specs of your package, they will tell you the price, then if it's like $100, subtract an inch off the longest side, and do that until it drops. Then you go your bike size. Also, you can check with the LBS, a lot of them could probably be able to tell you the right size.