Originally Posted by cornucopia72
Size of suitcases is not as critical as weight. The airlines have always weight our suitcases and never measure them. Some airlines will charge extra for any piece over 50 lbs., as much as $100.
I've only traveled with the single a handful of times. I think that flying first class and explaining that I was on my way to a charity ride event got the box on free the first couple of times. As the airlines are squeezed for revenue these days, they're a lot more likely to stick to their written policy and charge as soon as they see the box. You'd better tell the truth, and if there's a whole bike in it they have every right to charge the $80 or whatever that they publish to carry a bike regardless of its weight.
The loophole is the tandem in two cases. Each case is not a bike, it's a weight and dimensionally legal piece of luggage containing only "bicycle parts". If it's size and weight legal, it flies free.