Really Weird Bicycle.

On 3/27/2013 9:05 PM, Sir Ridesalot wrote:
I think this would be uncomfortable to ride for any length of time. I a;so wonder how the rider can see what's ahead when his head is down on the pad.

http://www.youtube.com/watch?feature...MXlr5_cpU&NR=1

Cheers

The logical progression of the upright bicycle.

--
T0m $herm@n

On Mar 30, 9:56*am, Ningi wrote:
On 30/03/2013 04:12, raamman wrote:





On Mar 29, 9:53 pm, Ningi wrote:

I was referring to Obree's world record attempt bike which looks ideally
suited for its purpose.

Pete-

why head first as opposed to feet first ?

aerodynamically, head 1st, the head up convention in obrees position
spoils the flow, a prism/mirror contraption keeping the head down
seems more efficent

we are used to seeing rockets and other projectilles conically shaped-
so again I would expect a feet first approach unless obree adopts a
superman position

not that I really care though- it's not a bike I would ever care to
ride

Shoulders are the widest part of body, therefore need to be at the front
for lowest drag - aka the teardrop shape.

Pete-

ah, butt (there's always one) I imagine that drag can be better
controled while aft, say a teardrop shaped helmet and shaped back
support, not a faring by definitition, but having a similar effect-
like my example bullets and rockets go point 1st~ maybe you are
correct, still I think it is important to question convention.

On Mar 31, 7:32*pm, Phil W Lee wrote:

Bullets are only pointed at the front for target penetration -
aerodynamically, it's better to have a boat tail with a round nose (so
back to that classic teardrop shape again, but with a truncated tail).

It's the partial vacuum at the back that creates most wind resistance
even at the (supersonic) speeds that give any benefit to tapering the
nose at all.
At subsonic speeds a rounded nose gives the least drag. *Not many
products from either Airbus or Boeing have pointed noses, despite the
high priority given to efficiency on modern aircraft.
I can't see any cyclist approaching the speed envelope where tapering
the nose to a point would be beneficial.
Tapering the tail, otoh, not only fills the space where that partial
vacuum would be created, but moves the centre of drag behind the
centre of mass, increasing aerodynamic stability (so an additional
benefit). *It's well enough understood that there are standard tables
for the degree of taper needed for any design airspeed.
The aim is for the taper to be gradual enough for the airflow not to
become detached.

So going head-first does have advantages aerodynamically, as you can
start the taper at the shoulders (well forward) and have most of the
taper done by the time you get past the feet (at the back) meaning you
only need a relatively short tail to complete the required taper to
zero. *Since all the skin has friction with the air, you don't want
any more than necessary.

I can't see how lying on your front would be very good for breathing
though - you can't take /all/ the weight through the hips without
tipping forwards, and taking any on the handlebars may impede control,
in the outstretched or "superman" position.
You might get away with it in "praying hamster" position, but isn't
that going to constrict breathing?
Any other position from those would increase frontal area, which would
be a big no-no. * A few square inches of frontal area are worth acres
of streamlining.

I agree with all of that. One more point: Putting the pedals in
front guarantees extra turbulence, because the spinning pedals and
legs stir the air pretty furiously. Also, the forward-moving pedal
has higher velocity relative to the surrounding air. I think this is
one reason that recumbents don't quite deliver on their aero promises.

Putting a fairing around (at least) the front of the bike could
largely fix that, of course. I think that would be preferable to this
"really weird bicycle," for many reasons.

- Frank Krygowski

On Wednesday, March 27, 2013 9:05:09 PM UTC-5, Sir Ridesalot wrote:
I think this would be uncomfortable to ride for any length of time. I a;so wonder how the rider can see what's ahead when his head is down on the pad.



http://www.youtube.com/watch?feature...MXlr5_cpU&NR=1



Cheers

The bike is very impractical in my opinion.

What if you had to jump off or make a quick maneuver ?

Your vision is pretty limited as well.

Andy