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'fairly' novel design

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Balor View Drop Down
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Balor Quote  Post ReplyReply Direct Link To This Post Posted: 07 March 2018 at 7:17am
Originally posted by bob walton bob walton wrote:

Yes, it balances like a normal bike. The way this happens is actually quite complicated because there are gyroscopic and other dynamic forces at work here too, but I will try to explain in simple terms. If you let go of the handlebars on a normal bike at standstill, the steering will tend to turn fully to one side (Wheel flop it's called). But on a bike with negative rake it will tend to straighten. This is a stabilising effect because you want the wheel to point the way you are going.
 
Negative rake AND "negative" head tube angle. Simply going for a negative rake on a conventional angle will only make flop much nastier due to proportionally increased trail.
Originally posted by bob Walton bob Walton wrote:

But if you are going round a corner of constant radius at constant speed, the steering has to be turned slightly to one side. On a bike with a negative rake the steering will not try to straighten the way it would if it was centred by a spring. And you don't want it to straighten because you are going round a corner of constant radius. 
 
That might very well be. I've read 'motorcylcle dynamics' by Cossalter and I admit that some parts are way too complex for me to understand fully, but I will eventually experiment with a spring and see how it compares.
 
Originally posted by bob Walton bob Walton wrote:

To prove that it works watch this video...
https://www.youtube.com/watch?v=lgJjgRtKNT4&feature=youtu.be
... where I ride an earlier version of the same bike no hands. You can't normally do that on a recumbent.
Wink
Well, 'self-stability' is thing that you either have or your don't. Being able to ride no-hands, however, is mostly a rider skill and does not really tell you anything about steering characteristics. There are multiple people riding MBB bikes effortlessly no hands (I cannot), there are videos of people riding 'conventional' SWB bents with tiller and even lowracers no-hands (most people cannot, indeed), there are reports that some people (circus athletes, mostly) being able to ride early FWD-rear wheel steering bents that absolute most people find completely unrideable.


Edited by Balor - 07 March 2018 at 7:44am
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Post Options Post Options   Thanks (0) Thanks(0)   Quote bob walton Quote  Post ReplyReply Direct Link To This Post Posted: 07 March 2018 at 5:06pm
I thought you could see from the videos it was stable. Most people that tried it, learnt how to ride it in about 2 seconds. If you don't believe me, I don't care.
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Post Options Post Options   Thanks (0) Thanks(0)   Quote Balor Quote  Post ReplyReply Direct Link To This Post Posted: 09 March 2018 at 10:21am
Oh, I do trust you - like I said, I've tried a similar design, and it rides fine (and would ride even better with a functional remote).
I just remind you that a video of riding no-hands does not actually prove anything conclusively :).
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