I read some of the "negative" commentary by the long distance rider
about his relative speeds ufaired bent vs. DF. When you consider he
was riding an unfaired Tour Easy, it's no wonder he was a bit
disappointed. He could have picked a MUCH faster unfaired bike.
Something like a Ti Aero would give him the kind of performance he was
looking for. Also, I wonder why he didn't use a fairing? Some
regulation for the rides he was doing? Put a Zzipper and sock on the
TE, and he'd be a much happier camper. It seems to me that one of the
great thing about so many bent designs is that one can mount a very
effective fairing so easily. If you can't beat 'em, put on a fairing
and a sock, and beat 'em!

Scott



(Scott) wrote in message . com...
Thanks, Barry. Very interesting!

Scott



"B. Sanders" wrote in message news:L_oob.52992$9E1.241427@attbi_s52...
"B. Sanders" wrote in message
news:lLoob.49717$mZ5.311118@attbi_s54...
We all know that fully-faired recumbents own all of the human powered
speed
records. But what about unfaired recumbents vs. upright (DF) bikes?

snip

V = velocity at a constant power output of 250 W
P = power needed to maintain constant speed of 40 km/h (~25mph)

V(mph) P(W) Bike Description
19.8 469 road bike (touring position)
21.7 362 road bike (racy position)
23.9 277 recumbent (seat hight 60 cm)
24.5 259 recumbent (seat hight 40 cm)
25.4 234 recumbent (seat hight 20 cm = low racer)
27.9 180 recumbent (seat hight 20 cm, with tail fairing)
31.6 135 recumbent (seat 20 cm, with full fairing, soft material)
42.8 75 recumbent (very aerodynamic hard fairing)

snip

Yes, folks, according to this study, that same 75 watts of power
that produces ~10 mph on your hybrid upright bike would have you screaming
along at 25 mph in a fully-faired lowracer. Wow.

Doh!

Make that *42.8 mph*, not 25 mph. Can you believe these numbers? 42.8 mph
for 75 watts of input? That is incredible; but it does begin to explain how
Sam Whittingham was able to power a faired bike to 81+ mph on level ground.
(remember: wind drag increases as the *cube* of velocity).

-Barry