From: mborgerding@desire.wright.edu
Newsgroups: rec.bicycles.tech
Subject: Re: side by side tandem
Date: 29 Sep 92 23:46:25 GMT
Organization: Wright State University


 (Daniel M Goldman) writes:
> I am not an engineer, folks, but perhaps some of you will 
> comment. 
> You've read about side-by-sides before, but this might be
> new.
>   
>    I propose that two totally independent bicycles could be made
> so that they can be linked together, with certain bracket or clamp
> members built or desiged in.

	<stuff deleted>
> 
> 
>     OK. Then there are all you na sayers.
>     1) "It can't be built stong enough."  
>       Come on you guys.  With the materials and physics available
>       to you today, is this really true?
> 
>     2) "its too wide"
>        Remember, with the turn of a few wingnuts, snap of a few clamps
>        or other such clever devices, you're right back to two wheelers
>        if the road is too narrow.  Where the path is sufficiently wide
>        or the traffic sufficiently light, go back to tandem.
>     
>     3) "The steering won't work".  You mean a few linkages can't be
>        designed to do this easily and simply?

	You forgot a few, Daniel. 

	4) By placing the two riders side by side, you have completely
destroyed all aerodynamic benefits achieved by a standard tandem.

	5) Who will steer?

	6) The more powerful rider will push the less powerful rider into the
side of the road if he/she isn't careful and constantly adjusting the steering.
Even this adjustment by the steering is an inefficiency which should not be
necessary.

	7) Bicycles are meant to lean into turns.  Without this leaning, the
center of gravity can easily capsize a couple that takes a turn a little too
fast. This effect will be amplified by the heavier person being on the outside
of the turn.  

	8) brakes.  Unless both riders apply their brakes equally, ( an event
about as likely as Sly Stallone playing Hamlet in the Royal Shakespeare Company
) the bike will tend to go into a spin of sorts, the severity of which will
 depend on the amount of difference.  This is somewhat related to #6.
> 
>     I am inclined to agree that for you power riders or off-the-road
>     people, this might not be an attractive item.  But it is to me,
>     and I think there are many other people who would be attracted to
>     this.  I realize I have oversimplified the problem from an
>     engineering standpoint, but I also don't believe it is anywhere
>     near as impractical or unmarketable as I have been told.  You
>     people work on bikes-is this really such a foolish desire, or
>     could some clever, innovative person really go-to-town on an
>     idea like this and DO something with it?  I'm sure this isn't
>     an original notion-if so, is it worth reexamining?
	It is definitely an interesting notion.  If it were to work, I believe
that it would have to be a one piece, three wheel model rather than two
individuals that clamp together. This could allow for a single set of drive
wheels, connected brakes and a single steering system( this could even be
designed so that either rider could "take the wheel")
					-Mark Borgerding
 
From: lous@hpnmdla.sr.hp.com (Lou Salz)
Date: Mon, 5 Oct 1992 23:02:14 GMT
Subject: Re: Re: how to patch a tube--cheap
Organization: Hewlett-Packard, Santa Rosa, CA