Our 2022 trip to Melboune and Tasmania was interesting, but the weather was cold and wet in Tasmania (early December was too early in their summer) and we did no motorcycling on the interesting coastal areas around Melboune. Also, we heard about a ferry from Geelong (near Melboune) to Devonport Tasmania. It's not cheap or fast, but it might be really interesting.

So here's the gist of a plan. Sometime between late January and March, fly to Melboune, rent scooters and explore the coast around Melboune. Then ferry over to Devonport. Rent bikes from xxx. Spend a week riding around Tasmania exploring the areas we missed in 2022. Fly back to Sydney and walk around or rent scooters there before finally heading home.

Bike rentals in Melboune

In Melboune there are several companies that cater to Uber and Doordash delivery drivers with rental scooters.
BikeRoundOZ a legit BMW, Harley, and other bikes including some low choices also several cities. BMW F700 in Launceston for AUS$180/day for min 7-day rental
motosparta a shop with lots of reviews but no rental bikes listed on their site
scootery few reviews, about $100/week for a 110cc scooter
Drivers Plus SYM ORBIT 2 or KYMCO AGILITY scooter

27 hrs and 2218 km, assuming 4hr or 300 km days that's 7 days --- one way

18h47m 1,388km is 5 days back to Melboune

11h0m 912km from Adelaid 3 days back to Melboune

Then you can take an overnight ferry from Geelong to Devonport

14hrs, 1016 km is about three or four days to do a lap of Tasmania