Calibrating a Turbo Trainer

Richie G
Richie G Posts: 283
edited January 2008 in Road beginners
Recently got a new computer with rear wheel sensor and cadence function - thought this would help me gauge how i'm getting on on the Turbo. Now i've read about roll down tests etc. but wondered if the following method would give me just as good idea of relative speeds:
Using a flat piece of road, i decided to work out which gear i used at 15, 18 ,20, 22 & 25 mph at my usual cadence. I then got on the Turbo and adjusted the resistance until i was achieving the same speeds in the same gear and at the same cadence as i had on the road.
I know this isn't particularly scientific but i think it should give me a rough idea of what i'm doing on the Turbo. Did a session last night and was surprised how hard it felt to get up to speed - think i might have been going a little easy on the turbo before! Any thoughts?