Check out this Delta Airlines baggage policy - -
Fees
You'll be charged an excess baggage fee each time you go over any one of the free allowances. For example, if you have an extra piece of baggage that goes over the weight limit and the size limit, then you'll be charged 3 times—once for the extra bag, once for going over the size limit, and once for going over the weight limit.
http://www.delta.com/traveling_check...gage/index.jsp
I knew that oversize had gone up, but they are really sticking it to cyclists.
Also - 80 inches - length + height + depth - is the max allowed.
(The AVERAGE Trek bike box is 88 inches - so you have to get a small one.)
What this means is that a touring cyclist with panniers will pay -
$100 for oversize plus $75 for additional baggage - - or $175 for the bike on Delta.
Each way!!
(And that's if they don't hassle him/her about paired panniers as single or double items.)
Not sure what the other U.S. airlines' policies are - probably similar.
I hope they all go bankrupt.