[trikes] steering design question

[Ian Sims]

In my biased opinion all these machines are compromised against normal bicycles from an efficiency and
performance point of view.

For a start you have only one person providing the motive power, so that the non-active person is deprived of
exercise, and the other person is overworked. Then you have the increase in weight and drag over a couple of
bikes. And finally terrible road holding, handling and balance compared to a bicycle.

This is why we have built recumbent tandem trikes, where one rider has hand cranks, and the other foot cranks.
These machines have performance that is on a par, or better than standard bikes. Plus the stability is better
than ordinary bikes. 

With such a machine, Karen Darke and her partner toured New Zealand and the Himalayas.

http://www.greenspeed.com.au/ownerweb.html


Regards, Ian
Ian Sims, Director
Unit5/31 Rushdale Street
Knoxfield VIC 3180
AUSTRALIA
Phone +61 3 9753 3644 
Fax +61 3 9753 4434 
Email ian at greenspeed.com.au 
Web www.greenspeed.com.au

Date: Thu, 28 Oct 2010 21:36:46 +0100
From: John Turvey <johnturvey at onetel.com>
Subject: Re: [trikes] steering design question
To: Alex Richards <alex.richards at orange.fr>
Cc: trikes at bikelist.org
Message-ID: <154F9E59-E2D3-11DF-B60E-00306566DC3C at onetel.com>
Content-Type: text/plain; charset=US-ASCII; format=flowed


On Thursday, October 28, 2010, at 07:21 PM, Alex Richards wrote:

> My wife was recently told she should use a wheelchair due to her ME. 
> As keen cyclists we'd like to continue, and so I've been looking at 
> designing an attachment for her chair which would convey it to 
> something like a Vietnamese cyclo rickshaw
>
> http://www.rfleming.net/diarypics/Huecyclo2.jpg
>
> Only thing I'm not certain about is the location of the steering 
> pivot; should it be between the wheels like a kids soapbox kart, or 
> behind the wheels like another conversion I've seen?
>
> Any advice would be gratefully received.
>
> Alex
>
>
There are several commercial machines available which are similar to 
this, where the wheelchair front and the 'cycle' rear can be split so 
the wheelchair can be used separately (in cafes etc) - however, the 
wheelchair part is much sturdier than a wheelchair, as it has to 
withstand the higher speeds of cycling - from my recollection of these 
sorts of machines, the steering pivot is slightly in front of the front 
wheel centres - to provide some trail and (presumably) damping to the 
steering.

Have you looked for this sort of machine on the web - a good starting 
point is the Velovision Special Needs Cycling Guide at

http://www.velovision.com/cgi-bin/show_comments.pl?storynum=559