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#11
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Getting into and out of streamliner recumbents
On 4/14/2017 3:48 PM, Frank Krygowski wrote:
On 4/14/2017 3:07 PM, DougC wrote: On 4/14/2017 12:44 PM, wrote: Interestingly enough a normal recumbent three wheeler is hard to get on and off of perhaps the two wheelers are easier. But I can hardly picture how you would get on and off of those streamlined ones. But I think that they are a good idea. Now only would they give you additional speed (a friend of mine who rides a standard two wheel recumbent says that it's reasonably easy for him to ride at 40) but also protection from the weather. Though the idea of windshield wipers for fully enclosed models appears to be somewhat daunting. Another thing is that you could have the streamliner painted a bright color to make it a lot more visible than a non-covered version. Velo windshields fog up on the inside surface, in the rain. The windshields flip up and end up being just a visor in rainy weather. The racing 2-wheel streamliners can't be used solo at all, since the shells are totally enclosed and are taped shut after the rider is inside. So far the /only/ 2-wheel streamliners I've heard of being sold for street use is the Peregrin-on-Birk http://speedbikes.ch/en/peregrin-on-a-birk/ it is built very nice but the typical delivered price is $30K - $35K. If you get a long-wheelbase recumbent and add a front fairing and bodysock, you can get most of the aero gains of a hard shell with very little cost and weight added. They look dorky but a decent job can add 5-7 mph to your flat-ground cruising speeds, assuming you have the gearing for that. I've wondered how stable those things are in gusting crosswinds. Any idea? Which thing are you asking about? The aversion to crosswinds from passing vehicles seems to be the main reason that nobody made a 2-wheel street streamliner until Speedbikes did. Also with velos (that are almost always tadpole trikes): they're a lot more popular in Euro-land, and they make it much more easy to ride comfortably in sub-freezing weather. If the pavement has a bit of snow or ice on it, you can still safely ride a trike but not with a 2-wheeler. So that is another reason. The body socks tend to have some give with crosswinds. Most people who go this route just buy the front fairing already made and add the body sock rear. A few people have built their own front fairings just for body sock use and it can work a lot better if it extends nearly down to the ground. Velomobiles and tadpole trikes do tend to have stability issues at times. The current trend is to use tadpole trikes that have 33%/33%/33% weight distribution per wheel. If they suffer a rear flat tire at high speeds, slowing to a stop without crashing can be very challenging. Velos (with their big noses that stick out well in front of the front axles) seem to be particularly susceptible to this problem. Delta-configuration trikes and velos don't seem to have it, but are comparatively rare in the high-performance market. |
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#12
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Getting into and out of streamliner recumbents
On 4/14/2017 6:10 PM, DougC wrote:
On 4/14/2017 3:48 PM, Frank Krygowski wrote: On 4/14/2017 3:07 PM, DougC wrote: On 4/14/2017 12:44 PM, wrote: Interestingly enough a normal recumbent three wheeler is hard to get on and off of perhaps the two wheelers are easier. But I can hardly picture how you would get on and off of those streamlined ones. But I think that they are a good idea. Now only would they give you additional speed (a friend of mine who rides a standard two wheel recumbent says that it's reasonably easy for him to ride at 40) but also protection from the weather. Though the idea of windshield wipers for fully enclosed models appears to be somewhat daunting. Another thing is that you could have the streamliner painted a bright color to make it a lot more visible than a non-covered version. Velo windshields fog up on the inside surface, in the rain. The windshields flip up and end up being just a visor in rainy weather. The racing 2-wheel streamliners can't be used solo at all, since the shells are totally enclosed and are taped shut after the rider is inside. So far the /only/ 2-wheel streamliners I've heard of being sold for street use is the Peregrin-on-Birk http://speedbikes.ch/en/peregrin-on-a-birk/ it is built very nice but the typical delivered price is $30K - $35K. If you get a long-wheelbase recumbent and add a front fairing and bodysock, you can get most of the aero gains of a hard shell with very little cost and weight added. They look dorky but a decent job can add 5-7 mph to your flat-ground cruising speeds, assuming you have the gearing for that. I've wondered how stable those things are in gusting crosswinds. Any idea? Which thing are you asking about? I was asking about two-wheel streamliners, like the Peregrin. Years ago, we briefly had a club member who rode a recumbent, to which he had fitted a homemade full fairing. It was a pretty crude, square-edged thing made (I think) of Coroplast, and he was a somewhat odd guy. Anyway, as we rode together on one invitational ride I was chatting with him, asking questions about his bike. When I asked "Do crosswinds have a bad effect on it?" or something similar, he got a bit irritated and didn't answer. The aversion to crosswinds from passing vehicles seems to be the main reason that nobody made a 2-wheel street streamliner until Speedbikes did. Also with velos (that are almost always tadpole trikes): they're a lot more popular in Euro-land, and they make it much more easy to ride comfortably in sub-freezing weather. If the pavement has a bit of snow or ice on it, you can still safely ride a trike but not with a 2-wheeler. So that is another reason. The body socks tend to have some give with crosswinds. Most people who go this route just buy the front fairing already made and add the body sock rear. A few people have built their own front fairings just for body sock use and it can work a lot better if it extends nearly down to the ground. Velomobiles and tadpole trikes do tend to have stability issues at times. The current trend is to use tadpole trikes that have 33%/33%/33% weight distribution per wheel. If they suffer a rear flat tire at high speeds, slowing to a stop without crashing can be very challenging. Velos (with their big noses that stick out well in front of the front axles) seem to be particularly susceptible to this problem. Delta-configuration trikes and velos don't seem to have it, but are comparatively rare in the high-performance market. The problem I've heard about with Deltas (vs. Tadpoles) is that if you overcook the entrance to a turn, the tendency to brake and turn simultaneously can get you in trouble, throwing weight too far forward (so to speak). Also, I guess it's easier and cheaper to design two wheel steering instead of two wheel power transmission, which requires a differential gear. -- - Frank Krygowski |
#14
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Getting into and out of streamliner recumbents
On Friday, April 14, 2017 at 1:48:53 PM UTC-7, Frank Krygowski wrote:
On 4/14/2017 3:07 PM, DougC wrote: On 4/14/2017 12:44 PM, wrote: Interestingly enough a normal recumbent three wheeler is hard to get on and off of perhaps the two wheelers are easier. But I can hardly picture how you would get on and off of those streamlined ones. But I think that they are a good idea. Now only would they give you additional speed (a friend of mine who rides a standard two wheel recumbent says that it's reasonably easy for him to ride at 40) but also protection from the weather. Though the idea of windshield wipers for fully enclosed models appears to be somewhat daunting. Another thing is that you could have the streamliner painted a bright color to make it a lot more visible than a non-covered version. Velo windshields fog up on the inside surface, in the rain. The windshields flip up and end up being just a visor in rainy weather. The racing 2-wheel streamliners can't be used solo at all, since the shells are totally enclosed and are taped shut after the rider is inside. So far the /only/ 2-wheel streamliners I've heard of being sold for street use is the Peregrin-on-Birk http://speedbikes.ch/en/peregrin-on-a-birk/ it is built very nice but the typical delivered price is $30K - $35K. If you get a long-wheelbase recumbent and add a front fairing and bodysock, you can get most of the aero gains of a hard shell with very little cost and weight added. They look dorky but a decent job can add 5-7 mph to your flat-ground cruising speeds, assuming you have the gearing for that. I've wondered how stable those things are in gusting crosswinds. Any idea? The designs are so varied that you can't say anything. The short wheelbase streamliners seem to be pretty unsteady but the longer wheelbase one, particularly with some suspension are pretty good from all accounts. |
#15
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Getting into and out of streamliner recumbents
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. |
#16
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Getting into and out of streamliner recumbents
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. |
#17
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Getting into and out of streamliner recumbents
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. |
#18
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Getting into and out of streamliner recumbents
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. 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. -- Regards, Joerg http://www.analogconsultants.com/ |
#19
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Getting into and out of streamliner recumbents
On Sunday, April 16, 2017 at 5:43:29 PM UTC-7, wrote:
On Friday, April 14, 2017 at 1:48:53 PM UTC-7, Frank Krygowski wrote: On 4/14/2017 3:07 PM, DougC wrote: On 4/14/2017 12:44 PM, wrote: Interestingly enough a normal recumbent three wheeler is hard to get on and off of perhaps the two wheelers are easier. But I can hardly picture how you would get on and off of those streamlined ones. But I think that they are a good idea. Now only would they give you additional speed (a friend of mine who rides a standard two wheel recumbent says that it's reasonably easy for him to ride at 40) but also protection from the weather. Though the idea of windshield wipers for fully enclosed models appears to be somewhat daunting. Another thing is that you could have the streamliner painted a bright color to make it a lot more visible than a non-covered version. Velo windshields fog up on the inside surface, in the rain. The windshields flip up and end up being just a visor in rainy weather. The racing 2-wheel streamliners can't be used solo at all, since the shells are totally enclosed and are taped shut after the rider is inside. So far the /only/ 2-wheel streamliners I've heard of being sold for street use is the Peregrin-on-Birk http://speedbikes.ch/en/peregrin-on-a-birk/ it is built very nice but the typical delivered price is $30K - $35K. If you get a long-wheelbase recumbent and add a front fairing and bodysock, you can get most of the aero gains of a hard shell with very little cost and weight added. They look dorky but a decent job can add 5-7 mph to your flat-ground cruising speeds, assuming you have the gearing for that. I've wondered how stable those things are in gusting crosswinds. Any idea? The designs are so varied that you can't say anything. The short wheelbase streamliners seem to be pretty unsteady but the longer wheelbase one, particularly with some suspension are pretty good from all accounts. I think that it is safe to say at least one thing: Also, having big airplane-style canopy windows means you boil in sunny/warm weather. .... and that is that this is an understatement; you are going to cook in all weather conditions. Put competitive cyclists on stationary bikes in the gym and they fall apart, I read. Until you put a fan in front of them. The cooling from airflow is an integral part of the system. This certainly lines up with my own experience and clothing preferences. |
#20
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Getting into and out of streamliner recumbents
On Monday, April 17, 2017 at 5:45:19 PM UTC-4, Doug Landau wrote:
On Sunday, April 16, 2017 at 5:43:29 PM UTC-7, wrote: Snipped Also, having big airplane-style canopy windows means you boil in sunny/warm weather. ... and that is that this is an understatement; you are going to cook in all weather conditions. Put competitive cyclists on stationary bikes in the gym and they fall apart, I read. Until you put a fan in front of them. The cooling from airflow is an integral part of the system. This certainly lines up with my own experience and clothing preferences. Again the reply was misinterpreted. Whn I said "like an airplane canopy" I was refering the canopy on a WW2 fighter was pushed rearward to enter or exit the aircraft and then pulled forward to seal it. I was NOT refering to a completely enclosed recumbent bicycle design. The rear or front of the recumbent fairing would be on a rails or other guides an would be moved to allow ingress or egress of the rider and then closed once the bicycle was in motion. Very lightweight rails/slots could easily be incorporated into the design of the recumbent shell. Then again you could have a hinged shell that opened up by pivoting forward then got pulled back down by the rider once the rider was on the recumbent.. Cheers |
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