jetbike model question

as more and more jetbikes models are being seen played by players, there are a few times I ran into this situations.

When shooting/assaulting, where do we measure from? From the 30mm base of the jetbike or the long shaped of the model (eg. reavers, screamers, etc)?

what's your verdict?

only vehicles are measured from the weapon/hull.. So jetbikes are measured to the bases they are supplied with. kinda weird for Reaver Jetbikes since their bases are smaller than their bikes, but that is how it is.

i would think measure from/to the base since they are not vehicles.