24 hr - 373 miles - good conditions, unsupported - Mersey Roads course of course, my first British TT
12 hr - 217 miles - average conditions - on the 24 hr course.
100 miles - just over 5 hours - reasonable conditions - some SPOCO course in Norfolk
50 miles - 2:12 or so - up and down the A50, no fun at all.
All on S&S coupled Frezoni Audax with Profile clip-ons, 32/40 spokes, all except the 100 mile in 2002 (the only distance I repeated in 2003, my last TT). It seemed like every week or two I was starting another TT half the distance of the previous one.
The only road TT distance done in Australia is 40 km (and that rarely), my fastest was a long 56 nearly 20 years ago on a flat, windless, virtually traffic-free course. I did a 2:20 100 km team time trial around the same time. I think I had a steel-forked Cannondale with tubs.
Track TT was 1:12 for a standing kilo - Chandler velodrome - steel Eddy Merckx, 28 spoke tubs, no aero bars. Flying 200 was 12.35 seconds.
It was nice to be fit once...