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Fairing / Shell for handbike or custom handbike

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Ken View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Ken Quote  Post ReplyReply Direct Link To This Post Posted: 25 November 2017 at 11:40pm
The Correx Fairing idea looks interesting.

I suppose the debate is: If I'm going to do this, do I just want to break current records or do I want to define a record unsurpassed since the dawn of time, a record that the leg powered folk with envy and dream to reach, one that will stand the test of time... and what's the right tool for it.

Especially if I'm going to have to travel so far to do it.

I've not tried riding a 2-wheeled handbike. In fact, I've never seen one. In the veleodrome debates I've had with a riding colleague, he's mentioned having seen a 2-wheeler on a velodrome before, but balance it a bit tricky, and I have some torso issues.

Aye, I'm in Scotland. But I've got relatives in the States so it'd be easy enough to get things sorted as long as I can get gear shipped over.

You still have the record handcycle? Faired, I take it? What's the record on it? I knew at some point but it's slipped my mind at the moment.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote JDub Quote  Post ReplyReply Direct Link To This Post Posted: 28 November 2017 at 10:47pm
I did mention to Alan Grace you might contact him. I think the dates are on the article Geoff sent. Alan would have gone full CAD/CAM, but time and money were not available, after wasting lots of time with Plymouth. Amongst a room full of sleek streamliners, that machine rather stood out.

Originally posted by Ken Ken wrote:

Aye, Karen's bike, I believe, is the F-1 designed bike she had in Rio. It did have a minor design flaw apparently, in that it was fragile enough that the drafting bar broke off which disqualified her on one of the races. And it does seem like the wrong design to attach a fairing onto (to me at least).

I suppose you could argue weight is both a pro and con, with the short run-up  of the handbikes it's be good for acceleration but the added mass giving momentum would also be beneficial once at speed. IT's probably one of the least significant factors on a flat run though (to a point).

I've seen the bike with the head steering and I'm baffled by it. It's excessively complicates and probably pointlessly heavy because of it. It didn't appear to be well shaped for aerodynamics (of course we all know that looks are very deceiving when it comes to aerodynamics though) and though the kneeling position theoretically allows you to put out more power, that's due in part to the ability to use your torso, and if your head is locked into the steering, you've just taken away that advantage.

I've heard rumours about a builder/ supplier in Scotland but had no idea who it was. A year with no delivery doesn't sound good at all.

Do you know when the Slug was designed? Lot's of resources available these days that can make for a more refined build (in so many industries).
jdub... Got the T-shirt
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JDub View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote JDub Quote  Post ReplyReply Direct Link To This Post Posted: 28 November 2017 at 11:10pm
I have the bike that set 4,000m, 10,000m and 1 hour at Manchester Velodrome. It only had a tail fairing and I don't have that. I widened it to 360mm across the cushion. Quite small. Also have a tilting 3 wheel version nearly working.  
Originally posted by Ken Ken wrote:

The Correx Fairing idea looks interesting.

I suppose the debate is: If I'm going to do this, do I just want to break current records or do I want to define a record unsurpassed since the dawn of time, a record that the leg powered folk with envy and dream to reach, one that will stand the test of time... and what's the right tool for it.

Especially if I'm going to have to travel so far to do it.

I've not tried riding a 2-wheeled handbike. In fact, I've never seen one. In the veleodrome debates I've had with a riding colleague, he's mentioned having seen a 2-wheeler on a velodrome before, but balance it a bit tricky, and I have some torso issues.

Aye, I'm in Scotland. But I've got relatives in the States so it'd be easy enough to get things sorted as long as I can get gear shipped over.

You still have the record handcycle? Faired, I take it? What's the record on it? I knew at some point but it's slipped my mind at the moment.
jdub... Got the T-shirt
http://s1127.photobucket.com/user/Protobikes/library
http://protobikes.org/
https://www.flickr.com/photos/150386999@N02/

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Ken View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Ken Quote  Post ReplyReply Direct Link To This Post Posted: 18 February 2018 at 12:59pm
Ah, right. Tail fairing is good but for those distances, I would think a nose of some sort would be very useful, not necessarily for speed, but just to reduce the power requirement for endurance.

I've not quite understood the tilting 3-wheel bikes. I was doing some reading on those the other day and so many of them seem to be designed to use one of the outrigger wheels all the time. If that's the case, why not simply use 3 wheels as normal and eliminate the weight and drag of the the extra outrigger? Sure, if you can get it up on two wheels it's advantageous, but the more recumbent you are (and handbikes are very recumbent) the more difficult it would be to keep balanced, especially with linked power and steering where an imbalance of power input affects steering which affects balance.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote JDub Quote  Post ReplyReply Direct Link To This Post Posted: 18 February 2018 at 1:20pm
The tilting 3 wheeler rides like a 2 wheeler but can be locked upright at a halt. It is intended as a trainer for the 2 wheeler. The bikes I built and on which records were set were 2 wheels. I only got as far as a tail fairing. They were designed for fully faired https://www.facebook.com/media/set/?set=a.315155438835071.1073741853.100010218519559&type=3
It includes a pic of the M5 2 wheeler, which has 2 wheels and a layed back rider. The layed back steering head used on conventional handcycles will not work on 2 wheels. The rest will. If you are going fully faired, the fairing has to go over the hand cranks, so might as well sit up more and make the machine easier to ride and more compact. If you can't see, send me a msg and I will send my email addr.


Edited by JDub - 18 February 2018 at 9:59pm
jdub... Got the T-shirt
http://s1127.photobucket.com/user/Protobikes/library
http://protobikes.org/
https://www.flickr.com/photos/150386999@N02/

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RoyMacdonald View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote RoyMacdonald Quote  Post ReplyReply Direct Link To This Post Posted: 18 February 2018 at 8:31pm
I'd agree Jonathan has most experience but you could also check out Varna and see if they have any ideas. http://www.varnahandcycles.com/handcycles.htm Georgi may be interested and they have a special projects department and certainly know a bit about fairings. 

Roy


Edited by RoyMacdonald - 19 February 2018 at 3:47pm
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Ken View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Ken Quote  Post ReplyReply Direct Link To This Post Posted: 21 February 2018 at 8:31pm
Thanks for the pictures Jonathan. Interesting design with the tilting 3-wheeler.

You raise a good point about the steering as that is definitely a balance with a handbike. A steering tube with a more vertical angle, I would think, would reduce the amount of power that could be put through the cranks as an imbalance in arm power would affect the steering more, requiring more effort and control to manage the steering. But, at an extreme with a horizontal steering tube, the power input is perpendicular to the rotation of the steering thus having less of an impact. And that, of course, has to be countered against the drag of 3 vs 2 wheels. Really all comes down to how much you need to steer for the use of the bike.

Aye, without covering the cranks you really might as well not even bother with a fairing. But, since a bike like a Force RX has the drivetrain, forks, and riders head and shoulders covered within the vertical travel of the cranks, you can effectively get a lot of coverage of the rest of the bike in the same shape. The main drawback that I I've encountered is that, giving enough clearance for the elbows results in a rather wide shell, and everything has to be fit within the restriction (or rather large size) of the cranks and shoulder area as a the limiting factor. You just can't sardine a handcyclist like you can a leg cyclist.

Given what I want to achieve, I'm not to concerned about the bike being easy to ride, what I'll be looking for is the most efficient power transfer and best aerodynamic possibilities to maximise the power that will be available.

 Thanks Roy, I hadn't thought about Varna. Don't really hear much about them over here.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote JDub Quote  Post ReplyReply Direct Link To This Post Posted: 25 February 2018 at 6:24pm
"A steering tube with a more vertical angle, I would think, would reduce the amount of power that could be put through the cranks as an imbalance in arm power would affect the steering more, requiring more effort and control to manage the steering. But, at an extreme with a horizontal steering tube,"

I don't know why you would think this. I don't think it is true at all. Control on 2 wheels is quite natural and there is no power loss.
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Ken View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Ken Quote  Post ReplyReply Direct Link To This Post Posted: 02 March 2018 at 4:44pm
I was just thinking of a situation where a rider might have an imbalance of power between their arms.
 A more horizontal steering tube puts the force of the power input perpendicular to the rotational movement of the steering rather than inline with it. With the force of power then working perpendicular to the steering movement, an imbalance might cause less of an interaction with the steering, thus lessening the need to reduce power to prevent extraneous steering inputs.

Similarly, in a situation where bursts of all-out power are needed, the less that power is in the same direction of movement as the steering the more the rider could focus strictly on the full implementation of power rather than compensating for steering.

Of course, this is all theoretical as, even a completely horizontal steering tube will not separate the movement of steering as power is applied due to the leverage of the cranks and hand position (as well as pedalling technique).

There are certainly advantages to a 2 wheel bike, but there are also advantages to a 3 wheel bike and I think it's finding the balance between the two in conjunction with the riders styles and needs. Some rider migh simply not be able to control a 2 wheel bike due to their ability to control their own body.
 
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Post Options Post Options   Thanks (0) Thanks(0)   Quote JDub Quote  Post ReplyReply Direct Link To This Post Posted: 04 March 2018 at 1:14pm
You are cranking both together. There isn't a difference of power. The difference made by steering is very slight. If the rider can balance on the back wheels of a chair, they should have no problem balancing a 2 wheel handcycle.  



Edited by JDub - 04 March 2018 at 1:16pm
jdub... Got the T-shirt
http://s1127.photobucket.com/user/Protobikes/library
http://protobikes.org/
https://www.flickr.com/photos/150386999@N02/

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