Spent last weekend in Lorne. Had a great ride on Friday from Lorne to Birrigurra return (82km). The Dean's Marsh Road is great on the way out of Lorne - a steady climb for 20 km at a fairly comfortable grade. Then about 6k down to Deans Marsh and relatively flat all the way to Birrigurra. Unfortunately drizzle set in on the way back and we froze going down the hill into Lorne from Sabine Rd (knees went blue).
If you want a real climbing challenge in Lorne, try to climb Hazel Rd and Summerhill Rd (its the first street on the right in Lorne coming from east).
Next morning rode out to the west along Great Ocean Rd. This is a fantastic road for a bit of interval work on the hills. But I imagine the traffic could be a problem at busier times of the year. Would love to travel a lot further on the Great ocean Rd - someday.
I like the signs around there which warn motorists of cyclists, especially where the road narrows. Might try to get something similar going here in Tas.