It'll be a long time before the whole car fleet turns over, and then you've got gasoline powered box vans and what not, too.

But as (or if) the liquid fuel demand drops, you'll probably see the density of stations drop too. Both fewer pumps per station and fewer stations. But I suspect most areas will have some gasoline availability for at least my lifetime. Worst case, auto parts stores will carry 5 gallon jugs prefilled with stabilized gasoline. That would get a motorcycle around quite a bit.

For old-timers who hang onto their classic gasoline powered cars, they might need to plan trips around fueling stations, like natural gas drivers and EV drivers currently do. (EV is easier, you can always bring a 110V charger and wait a long time)

Thing is... there will likely always be gas stations catering to vintage vehicles and such. Bikers will have to pay premium for bio-ethanol or such meant for exotic and old cars. Luckily motorcycles are generally decent (not great) on gas mileage, so it might work out OK.