I ran across this artical supporting your findings yesterday. I used
to think smaller and harder was better but after riding a greenspeed
tandem trike for a couple of years have changed my mind.

http://www.rivbike.com/node/18

Lee

--- In usarecumbents@yahoogroups.com, "Terry Farrell" <mfarrel2@...>
wrote:
>
> I ride a 2006 Rans Stratus XP with dual 26" Velocity wheels and
> Schwalbe 559-28 (26" x 1.1") tires. I also have a set of the same
> Velocity wheels (same rims and hubs, but fewer spokes) in the 650
> size from my Bachetta that have Continental Ultra Gatorskins 571-23
> (650 x 23 cm) on them.
>
> I was curious if the 650 wheels with their thinner tires might have
> less rolling resistance than my 26-inchers. So I roll-tested both
> sets of wheels/tires. There is a hill near my home with a
relatively
> steep initial slope and then levels off to a steady shallow slope.
I
> started each run from a dead stop, accelerating by gravity alone. I
> noted the time elapsed at the bottom of the hill, 1.05 miles from
> the start. I did 3 runs with each wheel/tire combo. Top speed was
> 23.0 to 23.5 mph and the runs ended at around 12 mph.
>
> The only variable I could not control was wind. I had a very slight
> tail wind of about 3 mph - and it seemed fairly consistent -
perhaps
> a little more tail wind with the 650 runs - there were a few flags
> with some movement, but when I tested with the 26" wheels, the
flags
> were completely limp - so I may have had a tad more tailwind during
> the 650 tests.
>
> Below are the tabulated results:
>
> 571-23
> Distance Seconds Ave.Spd.
> 1.05 254 14.88
> 1.05 253 14.94
> 1.05 246 15.37
> 1.05 251 15.06 Average
>
> 559 - 28
> Distance Seconds Ave.Spd.
> 1.05 243 15.56
> 1.05 258 14.65
> 1.05 251 15.06
> 1.05 251 15.08 Average
>
> If these numbers are to be believed as meaningful, it would seem
the
> two sets of wheels/tires have approximately the same rolling
> resistance. Both types of tires were pumped up to between 120 and
> 125 psi. Perhaps it is true what they say about fatter tires at the
> same pressure have lower rolling resistance than thinner ones.
>
> The wider tires have a noticeable smoother ride. I think I'll be
> keeping the 559s on rather than going to the 650s.
>
> Hope this is of interest to someone.
>
> Terry Farrell
> Tampa, Florida
> 80 degrees & sunny today!
>