the ultimate riding machines
IThe idea of a fully adjustable bike came about by my experiments with the design and construction of a bike with self levelling suspension. The idea was based around a pivoting beam whereby the saddle would be mechanically connected to the handlebars so that the rest of the frame including the wheels would move independently as they reacted to the bumps and troughs in the road. This arrangement would isolate the rider from vibrations caused by the above and theoretically work in a similar way to a tandem axle set up on a large truck or trailer. To test the design a conventional bike frame was suitably modified by adding an additional pivoting top (seat) tube with the saddle mounted at one end using a conventional seat post and clip. As construction progressed I realised that the pivoting top (seat) tube had now aquired saddle adjustment in a horizontal plane and was no longer restricted by the conventional seat tube angle. Similarly the saddle height could also be adjusted to a much greater degree by using the pivoting top (seat) tube albeit in a different position and angling it to whatever height was required. Abandoning the suspension idea I decided to develop the above system instead and a new frame was designed so that the top (seat) tube pivot could be located near the headstock and a variable telescopic support tube could be mounted below it to maximise the adjustment concept. This new layout resulted in a space frame design that was the best and most elegant way of achieving all my ideas regarding saddle adjustment mentioned above.
The frame design looked good on paper so I decided to build a prototype to prove both the saddle adjustment system and the new space frame design that accommodated it. To do this a standard bike frame was used adding the smaller tubes and then cutting away the remaining tubes that were not required. The pivoting seat tube was added and to get the bike on the road a standard quill type handlebar stem was used as the variable adjustment system for this came later in the development of the bike.
The prototype was then tested over a period of 18 months and with regard to the structural design of the frame it proved to be at least as stiff, if not stiffer, than a conventional one. The saddle adjustment system also proved to be very effective as not only did it cater for my height and reach (saddle setback) but it also enabled me to "Home in"" on my ideal riding position. This was verified when a thigh pain that I had experienced on my conventional bike simply vanished after experimenting with the new saddle adjustment a few times until my riding position felt just right.
The protoype was a joy to ride and it also created a lot of interest with fellow cyclists and non cyclists alike wherever it went. This interest spurred me on to to design and build a special frame building jig from which a production version of the prototype could be produced. A testament to the design of the prototype was that I found no reason to change the basic design of the space frame when constructing the production version and when put side by side they look identical. An infinitely variable handlebar positioning system was also designed and built to make the resulting bike truly fully adjustable and thus enable any rider to achieve their optimum riding position.