According to the info on the American airlines website, if your bike box is more than 62 inches (length+width+height) then you will be charged $80 EACH WAY. This assumes that the bike is one of your two checked bags. If you have two bags to check in addition to the bike, you will pay $80 additional EACH WAY for the extra bag. And if that were not enough, if your boxed bike weighs more than 50 lbs you will be charged another $25 EACH WAY in addition to the above fees. I'm not making this up.

https://www.aa.com/content/travelInf...e%20and%20Fees

It would be very difficult (if possible) to get a regular size bike in a 62 inch box. Basically, the airlines are sticking it to passengers who want to bring something other than a couple suitcases with them. For the cost, I'd buy a cheap xmart bike, ride it while you are there, then donate it to the Salvation Army when you come home.