[geeks] Electric bike?

[Francois Dion]

On 7/18/06, Sheldon T. Hall <shel at tandem.artell.net> wrote:
>  Saith Francois Dion ...
> > I've just been trying to figure a mechanical way to drive through the
> > regular chain.
>
> You need a co-axial arrangement through the regular bottom bracket.  The
> motor drives a sleeve inside the BB, and the normal BB axle is inside of
> that.  Two layers of bearings, of course: BB-sleeve, and sleeve-axle.  The
> chainrings are on the sleeve, and a one-way clutch lets the BB axle (and
> thus the pedals) drive the sleeve.

You'd think this would be a common tandem option. Didn't some BMX work
this way? And then there was the Shimano positron, but I've actually
never ever seen one. Went the way of the Biopace.

> > BTW, What kind of road bike you got?
>
> Since I can't really ride any more, I'm down to two.  A very early seventies
> Mercian (probably off-the-peg) I bought used, and a Geoffrey Butler I had
> built in (I think) late '73.  The Mercian was, in theory, a dual-purpose
> racer-tourer, but it's a pretty relaxed frame and I've only used it as a
> tourer.  The GB is more of a time-trial bike.

I'm familiar with the Mercian, and I altough I read GB I tought CB:
claud butler. Apparently there is no connection except both are
british. Was Geoffrey Butler a frame builder?

Francois