There isn't any problem with the size. Perhaps it is a safety issue, where when the airbag goes off, the inflating airbag hits the tank bag and rips it off, turning it into a projectile to hit the rider.I'm agree, but this link( http://wingstuff.com/products/37911-gas-tank-pouch-for-2018-gold-wing) tell me :for airbag model not allowed!?