Hands as well as feet?

[Andy in Sig]

I saw a thing on local telly the other day about a handicapped bike marathon. The overwhelming majority of the competitors had no use of their legs and so were using arm powered trikes, everything from serious recumbents through to a third wheel attached to the front of wheelchairs. The local able bodied mayor took part and said that it was knackering but great fun.

This got me thinking that given that tandems have two power sources, would it be technically feasible to develop a recumbent trike where you used both your hands as well as feet to power it? It would probably be one of the best allround fitness devices ever made as well as being very fast. What do you think?

 

[Globalti]

Great idea at first sight but.... why hasn't anybody already done it? I'm sure I've seen pictures of failed attempts in the past; my thoughts are that the human brain needs at least one unmoving reference point for steering the bike and that if both feet and hands were moving the brain would simply be unable to cope with the complex task of steering and balancing the bike.

 

[Gromit]

It has already been done, www.berkelbike.com

 

[Andy in Sig]

That's the principle although the picture shows it being done using a modified wheelchair. I was thinking more of a seriously fast recumbent.

 

[Fnaar]

How a bout a specially designed recumbent where two people make lurve whilst going along... limbs flying everywhere, all that passionate energy to harness?
You'd have to let the woman steer though

 

[Joe24]

How a bout a specially designed recumbent where two people make lurve whilst going along... limbs flying everywhere, all that passionate energy to harness?
You'd have to let the woman steer though

Could have one so when there is the movement, like the matress on a bed moving, it propells the bike along.
The more action, the faster the bike goes.

 

[Arch]

It's been invented and reinvented, over and over. See for example:

http://www.alibaba.com/product/uk100723247-100480596-101221203/Robbobike_Bicycle.html

The problem is, no matter how many limbs you have, and use, you only have one power supply and that is dependent on what you eat, how fit you are etc. Use arms and legs and your energy is used up more quickly. So you might get a short term sprint benefit, but you'll tire out faster - it would be like running two motors off a battery, instead of one, the battery dies sooner.

Also, I gather that unless you train a lot, or are dependent on arm power, the additional power you get from your arms is a fraction of the power you have in your legs, so the advantage is nothing like doubling.

(All this I have learned from Mike Burrows, who knows a thing or two).

So basically, yes, there might be short term sprint applications, but nothing mainstream enough to make it seriously viable as a mainstream product, outside the area or special needs - where people might well benefit from spreading the load if their legs are weak.

Tandems of course, benefit from double the power source, for less than double the weight, but they are still two limbs, one power source.

 

[byegad]

The thing has to be heavier than a normal bike with extra losses in efficeincy.

The bottom line is that a really fit cyclist can use his legs to work so hard his heart, lungs and energy supply cannot keep up.

Why do you need to use your arms as well except to run out of power in a shorter time?