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Recumbent What IS that thing?! Recumbents may be odd looking, but they have many advantages over a "wedgie" bicycle. Discuss the in's and out's recumbent lifestyle in the recumbent forum.

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Old 04-13-04, 02:45 PM   #1
rogermo
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clwb plans

I came across a web site that had a clwb. Its called the low V. It is a version of Mark Stonich and David Siskinds clwb. If anyone is interested you can go to quisitive.net. On page six of the low V he has the plans that he used. The plans are for someone 5' 7" with 29" inseam. So if your taller add a couple of inches to the back of the tubes. Have a nice day Roger
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Old 04-15-04, 04:55 PM   #2
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Originally Posted by rogermo
I came across a web site that had a clwb. Its called the low V. It is a version of Mark Stonich and David Siskinds clwb. If anyone is interested you can go to quisitive.net. On page six of the low V he has the plans that he used. The plans are for someone 5' 7" with 29" inseam. So if your taller add a couple of inches to the back of the tubes. Have a nice day Roger
Question: what is a "clwb"?
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Old 04-15-04, 05:12 PM   #3
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CLWB- Compact Long Wheel Base Its a style of recumbent. Along the lines of Bike-E, Big-Ha, Cannondale.
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Old 04-24-04, 10:11 PM   #4
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Originally Posted by Canuck1
Question: what is a "clwb"?
Compact long wheel base- sometimes referred to as a medium wheelbase recumbent.
The cranks are slightly behind the head tube and the rider sits above the rear wheel.
A compact front wheel is used to help the pedals clear the front wheel and a smaller rear wheel helps keep the rider height fairly low.

Easier and less expensive to construct and less of a transition for riders from uprights in their handling attributes relative the lwb and swb bents. Less chain management difficulites. Not generally as strong aerodynamically as the other bent bikess and higher rolling resistance with the smaller wheels, although Burley uses some 20/26 wheels on clwb models.

EZ-1 is another prevalent example of this genre.
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Old 04-25-04, 11:29 AM   #5
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Originally Posted by meb
Compact long wheel base- sometimes referred to as a medium wheelbase recumbent.
The cranks are slightly behind the head tube and the rider sits above the rear wheel.
A compact front wheel is used to help the pedals clear the front wheel and a smaller rear wheel helps keep the rider height fairly low.

Easier and less expensive to construct and less of a transition for riders from uprights in their handling attributes relative the lwb and swb bents. Less chain management difficulites. Not generally as strong aerodynamically as the other bent bikess and higher rolling resistance with the smaller wheels, although Burley uses some 20/26 wheels on clwb models.

EZ-1 is another prevalent example of this genre.
There is a Linear clwb on ebay for 2 more days.

I'm confused with rolling resistance. I had thought a smaller wheel had less rolling resistance because less of the tire would be touching the road surface????
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Old 04-28-04, 01:52 AM   #6
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Originally Posted by lowell
There is a Linear clwb on ebay for 2 more days.

I'm confused with rolling resistance. I had thought a smaller wheel had less rolling resistance because less of the tire would be touching the road surface????
The rolling resistance caused by the tread flexing is much less than the sidewall flexing and the loss due vertical deflection of the bike.

A larger tire has a greater tendency to bridge itself across concave road portions such as holes or cracks or bumps in the pavement so the vehicle is deflected less in the vertical direction. The smaller tire is more apt to trace the contour of the concave surface moving the bike up and down and converting the horizontal kinetic energy to vertical kinetic energy which is usually not returned to the bike’s horizontal direction. This is more so in downward deflections than upward deflections. Keep in mind, nearly all concave surfaces also have an offsetting convex surface.

With a 16” pneumatic tire at 80 psi you have the same amount of tread contact patch buoying you up in contact with the road as with a 26” tire at the same pressure- the 26” has to flex less make the flat contact patch so there are lower losses here as well. With the 16” tire, the sidewall will flex more to make the contact patch flat at the road.

The 26-28” diameter of the road bikes is not an accident or arbitrary selection. It is a great compromise between low rolling resistance vs. low tire weight and nominal rider leg length accommodation. Rolling resistance increases significantly with tires smaller than 20” rather than than mild difference between 20 and 26.”

On a smoother surface such as a velodrome, the rolling resistance disadvantages of a smaller tire are substantially reduced and the aerodynamic advantages of a smaller tire sometimes will exceed the rolling resistance losses.
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Old 04-28-04, 05:55 PM   #7
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Originally Posted by meb
The rolling resistance caused by the tread flexing is much less than the sidewall flexing and the loss due vertical deflection of the bike.

A larger tire has a greater tendency to bridge itself across concave road portions such as holes or cracks or bumps in the pavement so the vehicle is deflected less in the vertical direction. The smaller tire is more apt to trace the contour of the concave surface moving the bike up and down and converting the horizontal kinetic energy to vertical kinetic energy which is usually not returned to the bike’s horizontal direction. This is more so in downward deflections than upward deflections. Keep in mind, nearly all concave surfaces also have an offsetting convex surface.

With a 16” pneumatic tire at 80 psi you have the same amount of tread contact patch buoying you up in contact with the road as with a 26” tire at the same pressure- the 26” has to flex less make the flat contact patch so there are lower losses here as well. With the 16” tire, the sidewall will flex more to make the contact patch flat at the road.

The 26-28” diameter of the road bikes is not an accident or arbitrary selection. It is a great compromise between low rolling resistance vs. low tire weight and nominal rider leg length accommodation. Rolling resistance increases significantly with tires smaller than 20” rather than than mild difference between 20 and 26.”

On a smoother surface such as a velodrome, the rolling resistance disadvantages of a smaller tire are substantially reduced and the aerodynamic advantages of a smaller tire sometimes will exceed the rolling resistance losses.
Will have to read your post a couple of times but thanks for the reply! It is interesting!!!!
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