Could you make the hoverbike require fuel? It's otherwise fine but it not needing any fuel turned all early-scout-type hover vessel builds obsolete. The hoverbike costs less to make and you drive it for free so there's no point in building any early HVs any more. I think the hoverbike is intended for your very first vehicle and then you should progress to better vehicles. Now the hoverbike is just too good. Having it consume fuel, preferably more fuel than a similar HV, would give you an incentive to build something else for your early scouting needs. Since you can get biofuel easily enough even in the beginning it should be no hindrance to have it require fuel.