On Tue, 18 Apr 2017 07:40:56 -0500, AMuzi wrote:

On 4/17/2017 10:29 PM, John B Slocomb wrote:
On Mon, 17 Apr 2017 13:06:01 -0700, Joerg
wrote:

On 2017-04-17 11:06, wrote:
On Monday, April 17, 2017 at 11:01:04 AM UTC-7,
wrote:
On Monday, April 17, 2017 at 3:19:05 AM UTC-7, Doug Cimperman
wrote:
On 4/14/2017 2:54 PM, Sir Ridesalot wrote:
On Friday, April 14, 2017 at 3:32:19 PM UTC-4, Doug Cimperman
wrote:
On 4/14/2017 2:22 PM, Sir Ridesalot wrote:


I'm surprised that noone makes a streamliner with a sliding
rear part of the body. Slidethe body rerarward to get in
and then pull it forward when ready to pedal away. It'd be
much like the sliding canopy on a WW2 fighter plane Such as
the P-40, the Hurrican or the Yak-3.

Cheers


Many home-builders have tried, but it ends up being too
heavy. Also, having big airplane-style canopy windows means
you boil in sunny/warm weather.

There is also occasionally, a commercial builder offering
tadpole trike (2-wheels in front) bodies where the whole
thing flips up (on either a front-end or rear-end hinge) to
enter and exit. These body shells end up being very flimsy
compared to a good velomobile, and much heavier besides.

When trying to build bicycle bodies--especially for practical
use--the main enemy is weight. All the main velomobile
manufacturers now have an all-carbon-fiber monocoque model as
their top offering, because despite being expensive it ends
up being less weight than any other method.

I did NOT mean for the entire thing to be enclosed. I was
thinking that the body shell would be in two halves a fixed
forward area and a sliding rear area. the seat would be fixed
to the front portion of the frame and the shell behind the seat
and at the side would be able to be slid rearwards for entry
and then easily slid forward to close it. That'd ba a heck of a
lot easier to do than whatthe video showed of fixing a fabric
cover. With a sliding shell you could even start pedalling and
THEN pull the rear part of the shell forward. Plus the shell
would add protection to the person inside in the event of a
fall or crash.

Cheers


Yea but it has the same problem--lack of stiffness. Any time you
have a big section of the shell movable, then that whole section
cannot contribute to the overall stiffness. So that's why all the
higher-end velomobiles now use monocoque carbon-fiber bodies.

Now that is a rediculous statement. The entire bottom half of the
shell should be reinforced carbon fiber with at least twice the
stability of a normal CF bike.

Doug - my plan would be to build the bottom half and develop it to
ride well without the top half. Then to build the front top half that
would attach in some manner that both strengthened and allowed the
front to come off so that you could service the drive mechanism and
the wheels. Then the same with the rear quarter and then the cockpit
cover.


If you do that make sure the bike can be ridden with the cockpit cover
retracted. I can't imagine it to be fun riding an enclosed "rolling
Zeppelin" when it is 105F while the sweat drops pool up in its bottom.
Unless they had a li'l "A/C" button.

Why not? After all judicious ducting would provide a 30 MPH breeze :-)

I have ridden the last few kilometers home in a bit cooler weather,
say 95 C and it was a lot slower then 30mph but it was doable.

But again, who would want to. After all you got the two cars in the
garage both with the air-con. Too hot, just take the car.


Though this is maybe just a idea at this point. The streamliners I
have seen on the Internet are built around more or less normal
recumbents so you have twice the necessary weight and
re-enforcement.


I have seen some on the bike trails that just have a clear plastic
deflector at the front. It is aerodynamically shaped but I don't know
how close that ride will come to a real streamliner in performance.
Probably not very but the rider won't sweat so much in summer so will
have more available energy.

Way back when, road racing motorcycles first used a rather small
fairing on the front which did, I believe, improve performance as they
very rapidly increased the size and coverage.

To be honest, I've always wondered why a fairing wasn't more common on
bicycles. It would be light and certainly small changes in drag is
very significant on a bicycle.


Well, it's not as if they don't exist:
http://www.zzipper.com/

and with a long history of 'prior art' too:
http://www.poziome.republika.pl/historia_obrazki.htm

But then again, just like your tin of alcohol, slow moving
items reduce ROI and so get no shelf space.

Exactly. It costs money to maintain inventory. Something Joerg doesn't
seem to realize. If it doesn't move then have a sale and get rid of it
(hopefully at the wholesale cost) and stock something that does sell.