Bicycles: Reinventing the Wheel for a Modern World

by Matt Bryan

Like any sport in recent years, top-level cycling has become obsessed with improvement, and that comes in the form of previously-unthinkable speed. To the untrained eye a bike is just two wheels and a frame, but to the devoutly religious sect of self-confessed “bike nerds”, myself included, the bike is a piece of art, and at its heart, the very thing that makes it move: a drivetrain.

Before 1937, the bicycle drivetrain was a simple and pure affair. The moustached and fearless racers of the early Tour de France editions rode exclusively fixed gear bikes; with just three components, a chainset, chain and sprocket, the bikes were light and hard work. For a typical day’s stage, a distance of almost 200km (124mi), ranging in gradients from flat to upwards of 15% and downwards of -20%, only one gear could be used, a compromise that limited speed on the flats leaving riders “spinning out” with excessively fast pedalling, but then left them “grinding” on the alpine climbs. By the start of the Second World War, Campagnolo and Simplex had pioneered what they called a “dérailleur”, deriving from the word for a train coming off of its tracks; it allow use of multiple sprockets at the rear, lined up in a cassette, which gave the ability to change gear ratios whilst riding and without having to use a whole lot of elbow grease to remove a gear that had tightened itself on through use. Needless to say, it was a transportation revolution, making a bicycle a much more accessible and less daunting affair.

At the same time came the mass adoption of the freewheel, radically different from the fixed wheel bikes that came before, allowing a rider to stop pedalling without bringing the bike to a complete standstill. There is nothing scarier than storming down a mountain having ridden up it on a low-geared fixed wheel, as when the wheel moves at speeds of 70kmh (43mph) or more, so do the pedals with the riders legs still attached! Fixed gear bikes became a relic, only used in track racing for their greater ability to conserve momentum (as some of the pedalling motion is driven by the already moving wheel), but they have enjoyed a considerable revival amongst urban bike-messengers and hipsters.

And that brings “a brief history of bicycle gearing” firmly into the modern era. Ever since the dawn of the derailleur, there has been significant development driven by the racers of the time in the development of additional numbers of gears. First incarnations of rear cassettes had as few as 2 or 3 gears, but by the 80s, 6 speeds were common and by the new millennium, Campagnolo introduced 10 speed, meaning when coupled with three chainrings, a bike could have 30 gears. But modern advancements have changed the way gearing is developed; last year, Campagnolo introduced the Super Record EPS 12 groupset to the pro peloton, an exotic name for an exotic technology with an exotic price tag. Almost every part from the crank arms, to the derailleur, to even the chainrings themselves are carbon fibre, and everything else is titanium. The electronic version is currently unreleased to consumers, but uses electronic shifters to change between gears quicker than any spring and cable actuated derailleur ever could, and with millimeter precision. The non-electronic version has a price-tag of £2600, so it's only reasonable to expect it to cost around £4000 on its full release. Granted, it’s ridiculously expensive; for the same price you could buy a decent used car, which has thousands more precision-made moving parts, but in many ways, you are paying for what you cannot see.

Road racers are, as a breed, obsessed with efficiency, that is getting the maximum speed for the power they put in, and when you cannot train any harder, the bike itself becomes the weakest link. Recent research has suggested that a typical race bike groupset of around £350 has an efficiency of 95% in turning the pedals’ motion into movement, and that something like the multi-thousand pound Super Record or Shimano’s new top-of-the-line Dura Ace, has an efficiency of 97% (not to forget the lesser weight which means less energy is required to ride against gravity). 2% seems minuscule, but a 60kg racer doing 320W will ideally achieve a speed of 38km/h, but if  2% less power is lost in friction, a 0.5km/h is possible, “free speed” and the difference between winning and losing a race.

But the two percent is not enough for some; an extra few thousand can buy ceramic bearings for the wheels, bottom bracket and the derailleur as well as adjustments like larger jockey wheels and a shorter chain which means the chain has to bend less and loses less energy. All these pretty ridiculous and pedantic alterations claim to save a whole percent more, giving a 98% efficient system, but that still isn’t enough for the most performance obsessed, lycra-clad ‘roadies’ around. Last year CeramicSpeed unveiled the fruits of almost a decade’s research and development, their chainless “Driven” groupset. Instead of the front cog driving a chain, the teeth are instead cut inwards and turn a carbon fibre driveshaft, which in turn transfers power to a vertical-tooth cassette. Using a stiff driveshaft eliminates the inherent issues of a chain, in that it doesn’t lose energy like a chain does when it has to bend. This also promises a much more constant delivery of power, for even more speed.

For me, and probably only me, this is an amazing development; a bicycle is on average between 50 and 80 times more efficient than a car and even 5 times more than walking in terms of energy used per unit distance. A car wastes a huge amount of energy as heat with a combustion engine, and even with an electric car, there is a huge amount of ‘dead weight’ to be moved, which is proportional to energy used, and walking involves an inefficient gain and loss of gravitational potential energy per footstep. With a world hungrier and hungrier for energy, surely it is only a good thing to reduce how much of it we waste, and one good step would be to give everyone £15,000 carbon fibre race bikes, but that’s just my view; maybe starting with using the lacklustre 6500% more efficient bike rather than a car would be a good contribution.