30mins (25mins top seat then 5mins bottom - like cooking a pizza!)
90mins - easy spinning at 90-100rpm. Again just getting used to the saddle and position with some higher cadence work.
Some news from Garmin - they are bringing out the long awaited pedals which can measure your power http://garmin.blogs.com/pr/2011/08/garmin-brings-power-to-the-people-with-vector-.html I think i'll have to wait till the price comes down (a long way). I sent the Garmin watch off for repair of the cracked screen today - amazed that they will do it for free, even though it was my fault and it's two years old.