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T O P I C    R E V I E W
Osiris Posted - 07/29/2017 : 05:53:31
Some time ago I got a close look at a WAW owned by someone in my area. I was surprised at the sheer volume required just to create clearance for the rider's feet and knees while pedaling, and that got me thinking about ways to minimize the bulbous front end. I started by creating some 3-D models in SolidWorks which could be animated. Using a human model based on my own dimensions, including a size 11 cycling shoe and 165mm cranks, I constructed a model of a conventional pedal arrangement:



By animating the assembly, I managed to create a volumetric model showing the amount of space required for pedaling inside the shell of the vehicle:



I then came up with an alternative pedal arrangement which considerably reduced the vertical distance that the rider's knees and feet would need to travel throughout each pedal stroke:



Here's an animation I created: https://www.youtube.com/watch?v=KZfWaRvcaI4

The result was an outer shell that was more aerodynamic, but without much of an increase in the length of the nose:



This was just a fun project for me, so I make no claims about how well it would work in reality.




25   L A T E S T    R E P L I E S    (Newest First)
Grant-53 Posted - 09/20/2017 : 13:04:31
Without a picture it is hard to tell what went wrong. Too many cranks and cables? I have dealt with Mexican firms and they are not clueless. How would you attack the problem?
warren Posted - 09/19/2017 : 09:33:08
The Mexico teams had two linear arm and leg powered streamliners that they brought to Battle Mountain this year. One went 10 MPH. The other they could not get working. Case in point.
Grant-53 Posted - 09/18/2017 : 19:04:09
A SWB recumbent would also fit on a bus rack. Expect the IEEE and the SAE to come up with standards for vehicle radar frequencies and transponders.
Grant-53 Posted - 09/17/2017 : 15:56:52
Yes, front wheel drive unibody with up to three seats offset and electric assist. The solo urban upright will likely be a Z frame I beam inside an aero shell. A belt driven internal gear hub in a 26" wheel and a 20" front. Tires are 1.5" tubeless. Racks on buses and rail cars.
In 1966 I attended the auto show in Buffalo. NY where only Simca had a unibody 4 cyl. front wheel drive car on display. People are going to see the value of not sitting in traffic for 45 minutes to get the 10 miles to their job. If cyclists can cruise at 25-30 mph then separate lanes will not always be needed. A great deal of education on the part of motorists and cyclists is needed.
carolina Posted - 09/16/2017 : 21:49:56
Good points:

Velos like the pod will probably be in front in usa. Self drive will help, but we need a government that will build bike infrastructure and alot of white paint & stencils.

Batteries will be very good in ten years

The composite industry is always making improvements to our supplies even in last 4 years. Thats the necessity of unibodies.

Usa people are not like Europe riders and l think the assistant motors will be sell points in usa.

Slaming down the front with push push pedals want do it.

velosRus.com
Joel DIckman Posted - 09/16/2017 : 18:49:43
quote:
Originally posted by Osiris




...I don't think my question is being addressed. My point was that the high end CF bikes you're referring to are NOT fundamentally different in design from the type of steel frame bikes that made their debut in the 19th century. The sorts of design changes we've seen over the span of a century are only incremental ones; the basic design is fundamentally the same.

My question with respect to velomobile design was whether it's design, like that of the bicycle, is already at such a state of refinement that a velomobile made a century from now will be essentially the same vehicle we see today. (An example of a fundamental design change is the replacement of a structural frame with a unibody design.)
[/quote]

Some velomobile and recumbent trike enthusiasts are trying to create machines that lean into turns in a way that is similar to two-wheeled recumbent bikes. This would allow three-wheelers to turn safely at higher speeds. It would also give trikes a very different ride "feel".

I ride both ordinary two-wheeled recumbents and one bike that has an attached sidecar. The sidecar-equipped machine is effectively turned into a trike, and whenever I go around a sharp turn I miss the ability to lean. Go around a turn too fast and I risk flipping over. Not good, especially with a kid sitting in the sidecar seat. Leaning velomobiles are heavier, more expensive, and more complex. Kind of like linear drives. But I think a well-engineered leaning velo offers a much more substantial benefit than making the nose a little more aero with a linear drive.

Lots of people love cycling, but are afraid to share the road with distracted motorists texting and talking on cellphones. Hopefully the driverless cars and trucks of the not-too-distant future will make human powered transport safer, and induce more people to venture out onto the streets. This could stimulate a growth in cycling generally, including recumbent development.

Safe riding,
Joel Dickman
http://lightningriders.com

These three prevent most accidents: seeing, being seen. & (usually) common sense.
carolina Posted - 08/19/2017 : 13:17:18
Amen!!!!!!!!!

velosRus.com
Grant-53 Posted - 08/19/2017 : 12:44:57
We call it the Conservation of Reality law. Reality cannot be created or destroyed by ordinary wishful thinking. The trick is to understand what works and why it works. Then you can measure improvements to see if an idea (hypothesis) will work (experiment).
DougC Posted - 08/19/2017 : 11:59:55
quote:
Originally posted by Osiris
Well that's what I was wondering about. It seems to me that there has been a convergence of opinion as to what constitutes the objectively "best" formula for velomobile design. ...


Because that is what has been found to generally work best.

Another way to look at it is to consider some of the efforts by industrial-design projects. You see these in press releases from time to time. Some of them even have crowdfunding pages to try to produce and sell them.

These velos are very "car-like" (even with four wheels), very upright and very stubby.
The shapes are usually streamlined somewhat, but they still have HUGE amounts of frontal area.
Some of them even include motors built-in, as--even when they boast about using composite construction!--they are so heavy and draggy that they really aren't practical to pedal very far or very fast.

The reason these are built so badly is because they were built by people who never actually had to use the things.
They were art-school projects, that only had to look different. That's why they love to include pointlessly silly things like hubless wheels. They really don't work very well in real life.

Another example was when Graehem Obree decided to jump into IHPVA racing. The first pics of his bike left a lot of IHPVA regulars shaking their heads.
He thought it was innovative, but {prone bikes} and {linear pedaling} was two ideas that have been tried many times and never did well in IHPVA racing.
And he did well anyway, because of his physique--but the bike obviously held him back.
A lot of us wish he could have gotten a GOOD bike and come back and tried again, but that never happened.
carolina Posted - 08/18/2017 : 21:05:07
When i ran the 10 car hauler to california and back for million plus miles l bought the varieze in Arizona, brought it home and worked on it. 170mph cruz any day. Ground speeds can get incredible, climbs to 10 thousand quick enough. Built in pacifica california / its a 91'. I have 1600 hours/inst rated.

Can't fly forever, need a velo & a boat.

velosRus.com
Grant-53 Posted - 08/18/2017 : 20:47:00
My wife is trying to get time off to go NC. Wow, a velo and a VariEze be still my heart.
carolina Posted - 08/18/2017 : 19:00:11
Your correct grant bout others help. I been around bondo bob/lakeland airport. He made these bd-5 jet molds l own. Only ones in the world, the bd is metal kit. Also worked with nick jones @ his shop in early 90's (white-lightnin, lightnin bug airplanes) married elaine dupont. Hes older now and enjoying the huspa plantation in s.c.. l have studied much with 12 years of sun-n-fun every april at Lakeland fla.. 31 years of flying, still flying my varieze. Iam fortunate to have finished the velomobiel unibody mold and 0 problems.

Osiris you should get up with bob at lakeland airport.

velosRus.com
Grant-53 Posted - 08/18/2017 : 12:41:42
We try not to being good Baptists;) There is very little literature on building recumbent bikes compared to upright designs. The regulars here are the experts. There is however much available on general design and engineering that can be helpful. Building $50k robots is not the same as HPVs but knowing about belt drives could be helpful. You may never know when a bit of technology from one field will prove useful somewhere else. The cut and fold methods for making aircraft seats could apply to recumbent seats. See some of the commuter rail car companies' websites. I worked for Testori America for six years in Quality mostly. CAF has a plant in town also. Schweitzer aircraft was based here until it was bought up. The founding family still is here. If you live near Orlando, Fl there are any number of businesses that might deal in mechanical design for automation.
The article Tony posted there was a reference to "High-Tech Cycling" by Edmund Burke, useful info even if only intended for uprights. On Quality the none mathematics "Completeness" by Philip B. Crosby is excellent. There are several good volumes and articles on aerodynamics. See W H Hucho and Joseph Katz as most often cited.
Speedbiker Posted - 08/15/2017 : 16:33:36
Speak of the devil...
Grant-53 Posted - 08/15/2017 : 09:44:40
The short answer is an elegant design has a high degree of fitness for use with a minimum of complexity and cost. The rest is looking at the numbers. The tricky part may be deciding what the customer really wants to do. Any product must be safe, efficient, convenient, and cost effective. If anyone is interested I can post some of my favorite reference books that I came across during 15 years of technical sales and twenty years in manufacturing. Many of you have had similar careers and have been generous with your wisdom.
carolina Posted - 08/15/2017 : 06:41:36
Ditto speedbike. "But" They are the most helpful, nicest, shareing, care'ing, people on the planets though! Look what they helped me do. Netherlands, demark, cz republic, Germany, france. All hardwares come from europe.

velosRus.com
Speedbiker Posted - 08/15/2017 : 06:28:43
Nope, because that would take a book. Not to mention including an education in aerodynamics, handling, braking, ergonomics, vehicle dynamics, structures, etc. And that would likely be followed by arguments from people who have never successfully built anything.
Osiris Posted - 08/15/2017 : 05:58:21
quote:
Originally posted by SpeedbikerGreat designs like the Milan SL and Daniel Fenn are popular because they go, turn, and stop very well for human powered vehicles.



That's what I want to find out. If you could list all the things that make Fenns and Milans such successful designs, what would they be?
carolina Posted - 08/14/2017 : 20:26:55
13 thousand cars per day.

velosRus.com
Grant-53 Posted - 08/14/2017 : 16:16:36
So how often are cars or motorcycles stolen?
Speedbiker Posted - 08/14/2017 : 13:43:06
Adrew, there are sound engineering reasons for each of the elements you noted. Some ideas are pretty poor, but builders use them just to be different. Somea are willing to give up a little performance just to gain something like greater handling or stability. But it's pretty easy to build something "unique" just to stand out from the crowd, only to end up standing out because your fancy machine under performs. Remember, the best riders are lucky to produce 1/3 of a horsepower during an hour ride. Most are more like half that. How much fun you can have with 1/6 to 1/3 of horsepower is very dependant on a good design. Great designs like the Milan SL and Daniel Fenn are popular because they go, turn, and stop very well for human powered vehicles.
Garrie L Hill Posted - 08/14/2017 : 12:52:39
You just described the concept of convergent evolution in engineering.

Garrie "carbon based lifeform" Hill
HPRA Co-Dictator of the East
for pics of some of my time and money sucking projects
http://s58.photobucket.com/albums/g277/cfbb/
and videos
http://vimeo.com/5513519


Osiris Posted - 08/14/2017 : 12:23:10
quote:
Originally posted by Speedbiker

Andrew, diamond frame bikes have been forced to stay the same by the UCI for the sake of competition. Much like NASCAR. Even if they never allowed bents, you would still see a much improved design. Engineering doesn't define the basic concept of the diamond frame bike, rules do. Recumbents are like the wild west. When I started in the 90s a P-38 was considered a competitive race bike. Thanks to adventurous designers and builders, our competitive race bents look different and wildly out perform P-38s. In 2013 I informally raced and beat an F-40 ridden by a well known racer in a 90 mile test. In coast down tests my NoCom was equal to the F-40. That's how far we've come. Similarly, velo design is driven by engineering. But we have quickly seen how aerodynamics controls much of it's design. To stray much from a Daniel Fenn is to stray from competitive performance. And few people want a cool looking, but slow velomobile.



Well that's what I was wondering about. It seems to me that there has been a convergence of opinion as to what constitutes the objectively "best" formula for velomobile design. All of them have three wheels instead of four. All of them have two wheels in front and one in back, rather than the reverse. All of them use the same circular pedal arrangement, and all of them (at least the pricier ones) use a light weight mono-body with no separate frame. There are still some noticeable differences in the overall shape, with some being quite a bit longer than others, but the basic design seems to have been pretty much nailed down.
Speedbiker Posted - 08/14/2017 : 11:42:32
Andrew, diamond frame bikes have been forced to stay the same by the UCI for the sake of competition. Much like NASCAR. Even if they never allowed bents, you would still see a much improved design. Engineering doesn't define the basic concept of the diamond frame bike, rules do. Recumbents are like the wild west. When I started in the 90s a P-38 was considered a competitive race bike. Thanks to adventurous designers and builders, our competitive race bents look different and wildly out perform P-38s. In 2013 I informally raced and beat an F-40 ridden by a well known racer in a 90 mile test. In coast down tests my NoCom was equal to the F-40. That's how far we've come. Similarly, velo design is driven by engineering. But we have quickly seen how aerodynamics controls much of it's design. To stray much from a Daniel Fenn is to stray from competitive performance. And few people want a cool looking, but slow velomobile.
Osiris Posted - 08/14/2017 : 06:21:35
quote:
Originally posted by Speedbiker

Doug, I think that falls under the categories of "how much does a bike commuter have/want to spend. And what performance are they looking for. Tough to beat the centuries old design for cost and convienence.



One other point those who haven't lived in Holland may fail to appreciate is that bike theft is epidemic there. Nobody is going to buy a top of the line $8000 bicycle and leave it tethered to a tree or lamp post only to have it stolen. What you see everywhere in Holland is rusty, dirty, and inexpensive bicycles which aren't going to attract thieves.

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