HOW WE DESIGN

Simple cycles serve people in both industrialized and developing countries. Simple cycles have the same modest yet important job, no matter where they are to be found—the job of transporting you, your cargo, and your passengers -- in a manner that is safe, efficient and enjoyable.

When you bicycle, you travel at 4X your walking speed, without using any more energy.

A utility cycle comfortably carries 4X the weight of cargo that you might carry on your back.

A utility cycle therefore potentially represents – for those who have little other choice but to walk – as much as a 16X improvement in personal transportation capability. Especially for those persons living in deep poverty, who are carrying goods to market and commuting long distances, 16X can be utterly transformative. 

We have done everything possible to make Simple cycles attainable and affordable by the hundreds of millions of persons in developing nations who realistically have almost no chance of purchasing a bike.

In rural areas of developing nations, a majority of the limited calories people ingest are consumed in walking long distances and carrying substantial loads. A good utility bike can reduce this beast-of-burden energy drain by as much as 80% when operating on passable roads over rideable terrain.

In industrialized nations, where often an excess of calories is consumed relative to the minimal muscular exertion demanded of us, having a utility cycle to ride on everyday errands can provide valuable escape from the health-destroying trap of the modern sedentary lifestyle. Multiple studies from developed nations find that consistently active bike commuters may live a decade of healthy, vigorous years longer than chronically sedentary (automobile and public transport) commuters.

Simple cycles are modular. They are built from pre-designed pieces (“modules”) that are held together with reversible fasteners (bolts or screws), so that they can be taken apart a piece at a time for repair, modification or compact transport. Frames can alternatively be pegged and glued together or even nailed; pieces do not then remain ‘modular’ in the sense of ‘able-to-be-easily-disassembled’.

If a Simple cycle needs to be resized or changed for any reason, you can unbolt it, adjust or replace one module/piece or a few, move things around as desired, add a mount almost anywhere you want, and put it back together, until it’s just the way you want it. This is fundamentally different from the inflexible configuration of monolithically-welded thin-wall metal frames and those built of composites. As an owner-builder, you don’t have to hunt down a specialized technician to modify or repair your cycle; you can make changes and repairs by yourself.

You can install almost any components which you have available. We show how the frame can adapt to almost any kind of wheel and any kind of transmission. Our Plans include instructions for creating mounts for virtually any kind of brakes.

You can very straightforwardly add accessories (by screwing on a new piece, or drilling a new bolt hole), something not easily done on thin-wall metal frames and composite-construction bikes.

Every part and subassembly has been designed and prototyped over multiple iterations, in a focused effort to maximize owner-buildability, to limit materials required to only those commonly available, to avoid the need for equipment-intensive machining or welding, and to do all this without compromising functionality.

Design is a process of compromise among mutually exclusive choices. This type of quandary is well represented by that old bike-builder maxim; "Cheap, durable or lightweight; choose any two." There are a great many consequential choices which the designer must make, and all must be held in mind and considered simultaneously.

Design is a process of questioning assumptions. If this process of questioning is not pursued in the concept or design stage, it will demand resolution in the prototyping stage. We proved many concepts and tested-to-destruction many prototypes over this last half century. We have trialed vehicles which hit a real sweet spot, and more than a few that had structural conflicts which could not be resolved. Failings were sometimes reworked to the point of acceptability; others could not be salvaged and were abandoned. The models we now offer have survived this winnowing process.

A noticeable departure from ordinary utility-bicycle design has been our inclusion of some models with 'recumbent' seating. For many persons, the term brings to mind very low and very reclined bikes of a solely recreational nature, but our design approach departs from this paradigm. Car-like ergonomics, car-like seat height, and traffic view and visibility made possible by taller seating and eyes-forward head position, all enhance continuous situational awareness and safety in automobile/truck traffic and mixed pedestrian/cycle environments. Recumbent seating offers ergonomically neutral and non-stressful long-distance comfort for any and every body. A recumbent seating position empowers adaptability for that large minority of persons who have mild or moderate special needs.  A lowered center of gravity generally enhances the stability of tricycles. The likelihood and severity of braking and impact accidents are reduced with a lowered and rearward center of gravity. Recumbency makes possible useful features not possible on our upright models. 

Most of our upright models have a recumbent equivalent.

Because the transmission of a modern bike (metal crankset, bottom bracket and bearings, drive sprocket, driven sprocket, chain) is the most complex, expensive, difficult-to-obtain and difficult-to-install subassembly of a bike, we are creating designs for less costly, fully-owner-buildable options.

Linkage-drive systems were used on the first generation of pedal-bikes back in the 1840’s. These worked, but generally limited speeds below 8 miles/12 kilometers per hour or so (a slow jogging speed), as any linkage drive (unavoidably-single-speed) still does today. Functional linkage-drives were used on a number of bicycle models in the half century of bike experimentation which ended in the 1890’s when the higher-cost chain-drive ‘safety bike’ was introduced.

Our Simple version of linkage-drive is readily owner-buildable, and for some people can serve until such time as a crankset and chain can be afforded and retrofitted. For handcycles – that are often designed to travel at walking speed only – the inherently low gearing of a linkage drive has few, if any, disadvantages.

Toothed sprockets/chainrings can be bolted onto the wooden hub of a wooden Simple wheel, and a sprocket/chainring can be bolted onto a wooden Simple crankset; add a matching chain and you then will have a fixed-gear drive with the gear ratio of your choosing. Sprockets and matching chain can be of bicycle type, motorcycle weight, or garden tractor strength; any and all will be installed in the same fashion and adjusted in the same manner.

If your chain breaks or a cog wears out, you can likely find a replacement in most cities or larger towns of the world. There is an exception to this: If you decide to use bicycle multi-speed sprockets and chain, such as a modern 9, 10, 11 or 12-speed 1X group-set, very many bike shops in developing countries do not yet carry parts for these systems. Such chains are narrow and are not interchangeable with wider old-style bike chains. If you’re wanting a multi-speed chain drive which will make finding parts as easy as possible, then a 6, 7, or 8-speed cluster and matching chain are your best bet, as these are most widely available. A multi-speed chain and sprocket can be used to build a single-speed transmission.

Modularity/removability means you can take your bolted-together cycle entirely apart and pack it, section-by-section or piece-by-piece, for compact shipping, or for long-distance bus, boat or train travel.

Most Simple models are of moderate weight, roughly comparable to steel-tube bicycles. Almost all of the two-wheel Simple models are thus efficient enough to serve the daily commuter or touring cyclist. Most Simple models can be propelled even by the strength of a middle-school child.

The Simple cycle uses reversible fasteners (ordinary moderate-cost bolts or screws) to achieve structural strength with minimal weight, and to allow disassembly, customization and repair.

Simple cycles are designed first and foremost for efficient use of human muscle power. Secondarily, they are designed to accommodate virtually any after-market power-assist, configured in a way that keeps the cycle efficiently operable by pedal power if the assist stops functioning. Electric motors and wheel hubs that put out 1000 watts or less should generally integrate well into the cycle's structure without need for major frame modification or reinforcement.