ok so i've not managed to get out on the bike much recently due to work and weather but been doing a fair bit on the excercise bike machine in the gym (boring I know). having started riding in the summer i managed 3 centuries before wionter set in so now my long riding has become very infrequent.

today I did a 20mile TT on level 6 (medium setting) over a preset hilly course (in the gym).

dist: 20miles
time: 1hour 1min 25sec
avge HR: 156 (82% MHR)
avg spee: 19.5

I reckon i could have averaged over 20 mph as i didn't decide to do a 20miler until after a good 15 mins or so. as i started closing in and realising i could/nearly did it in one hour i thought....

...is this any good? more specifically what kind of time would an average cat pro, 1, 2, 3 & 4 rider expect to post on an average course?