Originally Posted by
Bacciagalupe
Raxel: iBike should be interesting...
It's not as good as a real power meter, but it may be the only option for a 20" wheeled bike.
A correction to your post, though.... Small wheels have more rolling resistance; see
http://www.users.globalnet.co.uk/~hadland/rolrec10a.pdf for details. I believe the issue is that the tires, and therefore the contact patch, is wider; the shape may also have an effect. Smaller wheels are faster because, even with wider tires, they are aerodynamically superior to 26" / 700c.
I've seen the data chart, and it only include conti GP 406 tire. (Which has RR of 0.0066)
I suppose stelvio 406 (28c), comet 451 (19c), and new durano 406 (27c) have lower RR than conti GP.
(I have seen a test which shows stelvio has lower RR than conti GP)
And german magazine Tour has tested a number of 700c tires years ago. You can google the web for exact data, and I here I show some of those tires which are 'slower' than conti 406...
Conti GP3000: 0.0067
Hutchinson Top Speed: 0.0069
Stelvio Tublar 0.0069
Tufo Elite jet 0.0073
Montello 300 tublar 0.0075
Tufo Hi-composite carbon tublar 0.0077
Conti GP Attack/Force: 0.0073/0.0057
I was quite surprised to see that widely used 406 tires such as stelvio are comparable to some of best 700c tires around, which means they rolls better than most 700c tires. There are some tires with RR as low as 0.0038, but I think it is not fair to compare a quite cheap and durable tire like stelvio 406 to expensive, race-specific tires with very shot life.