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Getting into and out of streamliner recumbents



 
 
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  #21  
Old April 18th 17, 04:29 AM posted to rec.bicycles.tech
John B Slocomb
external usenet poster
 
Posts: 356
Default Getting into and out of streamliner recumbents

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.

Ads
  #22  
Old April 18th 17, 04:29 AM posted to rec.bicycles.tech
John B Slocomb
external usenet poster
 
Posts: 356
Default Getting into and out of streamliner recumbents

On Mon, 17 Apr 2017 11:01:03 -0700 (PDT), 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.


And the proof is, of course, .... that is how a boat is built :-)

Years ago I read an article, in bike magazine, about an English
engineer who commuted 50 miles to work and 50 miles home on a
streamlined recumbent, so apparently it is possible. It was a long
time ago but from memory he didn't own an automobile.
  #23  
Old April 18th 17, 04:29 AM posted to rec.bicycles.tech
John B Slocomb
external usenet poster
 
Posts: 356
Default Getting into and out of streamliner recumbents

On Mon, 17 Apr 2017 11:06:05 -0700 (PDT), 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.

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.



That would work. Engineered, perhaps with internal reinforcements to
support the weight and energy, and a very thin upper half simply for
streamlining. It probably would be rather expensive, but certainly
doable.
  #24  
Old April 18th 17, 01:40 PM posted to rec.bicycles.tech
AMuzi
external usenet poster
 
Posts: 13,447
Default Getting into and out of streamliner recumbents

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.

--
Andrew Muzi
www.yellowjersey.org/
Open every day since 1 April, 1971


  #25  
Old April 18th 17, 02:33 PM posted to rec.bicycles.tech
Sir Ridesalot
external usenet poster
 
Posts: 5,270
Default Getting into and out of streamliner recumbents

On Monday, April 17, 2017 at 11:29:54 PM UTC-4, John B Slocomb wrote:
Snipped

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.


I think that the C is a typo and you meant 95 F? ;) After all 95 C is 203 F and that's a bit hot to be riding anything.

A fairing shell could have longitudinal ribs for stiffness without being too heave and as you mention you could even design in cooling vents.

Cheers
  #26  
Old April 19th 17, 04:04 AM posted to rec.bicycles.tech
John B Slocomb
external usenet poster
 
Posts: 356
Default Getting into and out of streamliner recumbents

On Tue, 18 Apr 2017 06:33:48 -0700 (PDT), Sir Ridesalot
wrote:

On Monday, April 17, 2017 at 11:29:54 PM UTC-4, John B Slocomb wrote:
Snipped

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.


I think that the C is a typo and you meant 95 F? ;) After all 95 C is 203 F and that's a bit hot to be riding anything.


Yes :-( it was. I converted 105 to Celsius and then converted 35 (C)
to Fahrenheit and then typed "C". Mia Culpa.

A fairing shell could have longitudinal ribs for

stiffness without being too heave and as you mention you could even
design in cooling vents.

Cheers


I once built a kayak with "U" shaped formers and longitudinal
stringers and covered with canvas. It would carry three kids and you
cold pick it up with one hand (if you grunted a little :-)
  #27  
Old April 19th 17, 04:04 AM posted to rec.bicycles.tech
John B Slocomb
external usenet poster
 
Posts: 356
Default Getting into and out of streamliner recumbents

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.
  #28  
Old April 19th 17, 03:30 PM posted to rec.bicycles.tech
[email protected]
external usenet poster
 
Posts: 3,345
Default Getting into and out of streamliner recumbents

On Tuesday, April 18, 2017 at 11:23:55 AM UTC-7, Joerg wrote:
On 2017-04-17 20:29, John B Slocomb wrote:
On Mon, 17 Apr 2017 11:01:03 -0700 (PDT), 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.


And the proof is, of course, .... that is how a boat is built :-)


Until one day the luck runs out ...

https://www.youtube.com/watch?v=Mz9hP81_7kQ


Years ago I read an article, in bike magazine, about an English
engineer who commuted 50 miles to work and 50 miles home on a
streamlined recumbent, so apparently it is possible. It was a long
time ago but from memory he didn't own an automobile.


This is an interesting streamliner commute:

https://www.youtube.com/watch?v=jePRQoWyMz4

He is lucky that he didn't get a speeding ticket.

--
Regards, Joerg

http://www.analogconsultants.com/


I didn't see any speed limit signs meaning his limit was 110 kph.
  #29  
Old April 19th 17, 04:01 PM posted to rec.bicycles.tech
Joerg[_2_]
external usenet poster
 
Posts: 6,016
Default Getting into and out of streamliner recumbents

On 2017-04-19 07:30, wrote:
On Tuesday, April 18, 2017 at 11:23:55 AM UTC-7, Joerg wrote:
On 2017-04-17 20:29, John B Slocomb wrote:
On Mon, 17 Apr 2017 11:01:03 -0700 (PDT),
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.

And the proof is, of course, .... that is how a boat is built :-)


Until one day the luck runs out ...

https://www.youtube.com/watch?v=Mz9hP81_7kQ


Years ago I read an article, in bike magazine, about an English
engineer who commuted 50 miles to work and 50 miles home on a
streamlined recumbent, so apparently it is possible. It was a long
time ago but from memory he didn't own an automobile.


This is an interesting streamliner commute:

https://www.youtube.com/watch?v=jePRQoWyMz4

He is lucky that he didn't get a speeding ticket.

--
Regards, Joerg

http://www.analogconsultants.com/


I didn't see any speed limit signs meaning his limit was 110 kph.


He blew through a 60km/h sign while above 80km/h AFAICS. In Europe that
usually results in an entry on your driving record if caught.

They even gave me a speeding ticket on a bicycle (!) in a 30km/h zone
where I was certainly not at 40km/h. Early 80's, cost me 20 Deutschmarks
but was low enough not to go on the record.

--
Regards, Joerg

http://www.analogconsultants.com/
  #30  
Old April 19th 17, 04:13 PM posted to rec.bicycles.tech
Joerg[_2_]
external usenet poster
 
Posts: 6,016
Default Getting into and out of streamliner recumbents

On 2017-04-18 20:04, John B Slocomb wrote:
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.


That is the philosophy of a simple sales guy or a short-sighted bean
counter. They come and go and nobody remembers them anymore.

I run a successful business for decades and my philosophy is different.
Customer service is key. A bean counter would tell me that it does not
make sense to keep lab equipment like a logic analyzer or stock of rare
long leadtime electronics parts that I won't need for years. The proof
that their philosophy is poor came once again two weeks ago. A client
had a line-stop in production because units started to fail final
testing, a nightmare for the executives at a manufacturer. Using that
analyzer and some parts allowed me to find the root cause very quickly
instead of weeks later after some long-leadtime parts are finally
delivered here.

The bike shop owner where I bought my MTB shares that philosophy, else I
would have bought it online for $100 less. When the saddle broke he had
a nice WTB saddle in stock. It's been there for many months, I could
quickly try it out and next day I could ride again. That was not a
profitable item for him. However, I steered two people to him to buy
bicycles there and he does not sell cheap low-margin bikes. That is what
I call a successful business strategy.

--
Regards, Joerg

http://www.analogconsultants.com/
 




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