As for goals, I just want to be fitter and faster. I have limited time (work, family etc) and am never going to be on a podium, but it'd be nice to being doing well generally for events such as 50k's, posting good lap times at things like SITS/Bonty 12, and generally trying to achieve that via the 3 rides a week I can manage consistently.
As some kind of indication - confirms with Pawsy's info - I did a 31k training mtb ride today, with the following stats:
Average speed 11.9mph
Average HR zone 3.9 (85% max) 158bpm
Max HR zone 5.6 180bpm
I'd really like to be riding at 12.5 -13mph average in 2012 on the same course.
Useful input everyone, thanks. - Good tip about limiting the road bike to the inner ring.