9er is correct. You may want to know that even when the bike is supported and the thru bolt has no pressure on it you may still need a drift pin and a dead-blow hammer to get it moving. I've installed several and all but one needed a bit of assistance to move all the way out. If you rteally got to wack it something is not ligned up but a tap or two is not out of the question. If it stops, like mentioned, look at the other side of the bike. The bolthead can get hung up on the rad shroud, but not on every bike.