The 19th century blockchain
The original block chain revolution
The block chain revolutionised the bicycle world. The structural trade-off between the strength of an overlapping chain and intersecting gaps that could connect with drive sprockets led to the development of the safety bicycle and the stable innovation of rear-wheel drive.
Before the block chain, bicycles had evolved from hobby horses propelled by pushing off the ground to pedals that directly drove front-wheels such as the boneshaker velocipede and the fatally inclined penny-farthing. Innovative bicycle designs show the ergonomic creativity of early designers.
The introduction of block chain took the industrial use of significant horsepower popularised by Brunel and scaled it to the sovereign power of the singular cyclist. Also known as the Humber chain, the block chain had large steel blocks linked together by pins and chain links. The original block chain is distinctive for the one inch sprocket spaces in the drive chain.
Steel blocks provided strength to the block chain and the links between provided the gaps for rear driven propulsion through an intersecting chain-ring. The rear-driven bike in-turn evolved the bicycles larger structural design giving the rider a safer central position and allowing more stable, balanced and practical wheel diameters.
The block chain reformed the bicycle design to resemble modern forms and through innovating stability and safety led to the mass adoption of the modern bicycle. Yet the blockchain came with trade-offs. The speed of the bicycle was reduced due to the transfer of energy between parts, and the block chain became a weak point in the bicycle system due to chain stretch around the curvature of the chain-ring. The original Humber block chain was replaced by a more fail-safe roller design but managed to prevail for a time in circuit racing where it was said to transfer speed better than the durable roller system.
The block chain was counter-intuitive. It led to a slower bike and introduced a new point of weakness due to pressure on the intersecting links where cogs would fit. Such idiosyncrasies still plague the modern cyclist with chain skipping, slippage and breakage often being the 1st symptom of a poorly maintained bicycle. The block chain’s promise to transfer a riders energy in a new way was also its weakness, a trade-off accepted by the risk-averse rider. At the heart of the block chain was not only the links and gaps where sprockets would intersect secure blocks, but the two pair-matched chain-rings. In tandem the chain-rings fill gaps in the block chain to propel it allowing a riders energy to be creatively routed to the rear wheel.
The fatalities of being thrown head-first over a penny-farthing were common-place and historically made cycling an environment populated by risk takers. The risks were even embedded in the penny-farthings design with mustache handlebars invented to allow riders to position their feet on the handlebars, so in the event of a fall at-least they would fall feet-first. The block chain reward is a stable bike allowing more people to ride freely without having the constant threat of losing control due to an unstable design.
