Quite a while ago Mars ... summer before last I'd say was the last time. But that's mainly because I haven't gotten out there nearly as much as I used to due to fitness.
Most recent SG sighting was in Boomers, I was stopped, and heard it slithering away. Only saw the tail of it disappearing. Prob 200m in from where it runs alongside KG-StA Rd. Same thing around Rob Roy area up top the year before. Both these were black. One colourful one across the top of the trail that goes from Clintons down to Motchalls. Probably 50% of the sightings I see (on all Vic trails) are off the trail, once I've stopped and been still long enough for them to think I'm gone I guess. I stop a lot ... so I reckon I've seen about a dozen this way over 10 years. The rest are seeing them on trail up ahead, and they're long gone by the time I get there. Once I ran over a black one on .... can't remember the trail name in Yaugher in Forrest. All those incidents combined led me to beleive that the circumstances of being bitten while riding would be so extreme: falling in an area where I'd seen one off trail, or deciding to stop when you're right on top of one. It was the latter that happened on the YT's (Westerfolds, alongside the river), had a rookie right on my tail, didn't want to ride over snake such that it went for him, so I stopped with front tyre centimeters from it. Little tiger had 3 or 4 goes at my spokes before wandering off. Slight velocity change and it could possibly have been my leg. So I no longer doubt it's possible. But still .... fkn unlucky if it happened.
Most recent snake sighting was with a friend - we were having a bite to eat and a rest at the chair/gate where the Yarra Trail goes from concrete to gravel just past where it goes under Burke Rd. Looking in the gnarly mess of trees on the banks of the river, we saw a 1.5m long tiger climbing a tree. Quite elegant.