Science: Bicycles

by Mark LaPointe

201 years ago, the precursor to the bicycle was invented in Germany. The year was 1817, and the “Dandy Horse” was the first human powered two-wheeled (in tandem) form of transportation.  Lacking any pedals, the rider used his feet to propel the Dandy Horse.  It took another 40 years for the modern bicycle to evolve.

In France in the year 1860, Pierre Michaux and Pierre Lallement attached pedals and a crank to a Dandy Horse, and the modern bicycle was born.  But it was modern only in the sense that it had two wheels, pedals, and a human-powered propulsion system.  It also had wooden – and later metal – wheels and was known as the boneshaker.  It was not fun to ride. Countless improvements later, the bicycle is still remarkably similar to its roots in the sense that pedals and a chain are still the way they move.

In the past several years, bicycles have experienced some incredibly huge changes.  The first of these has been the e-bike revolution.  Over a century ago, motorized bikes were the early precursors to the motorcycle.  According to the U.S. Patent Office, the first patent filed and granted for an electric bicycle occurred in late December 1895. Battery technology held back the performance and efficiency of e-bikes until more recent times.  Today, less expensive e-bikes utilize lead acid batteries, which are heavy and have less electrical capacity than lithium ion batteries.  Lithium batteries are also a lot smaller, which makes them more efficient to use in electric bicycle design.

Most e-bikes have an electric motor located on the hub of the bike, usually on the rear wheel.  Interestingly, according to the U.S. Patent Office, the first hub motor patent dates back to 1883, when Wellington Adams targeted the rail car industry with his invention. Hub motors produce torque to propel the e-bike using energy from the battery.  According the Electric Bike Report, hub motors come in single speed direct drive and geared motors.  Direct drive motors are slower, but produce more torque, meaning that the rider can carry more. Geared motors are faster, weigh less, and the rider can achieve higher speeds.  They cause less drag, but are also less durable.

Electric bikes can either provide an electric assist or power the bike completely.  There are myriad options when it comes to e-bikes, and some are completely powered and without pedals.  The benefits of electric bikes are that they can help riders travel farther and allow those with disabilities to cycle again. The downside is that in professional cycling, where cheating is always a problem, hidden electric motors have been discovered during race inspections. E-bikes also have also experienced a mixed reception among the cycling communities, with many riders against their use.  Many national parks restrict e-bike use on trails, as do many state and local parks.  While there has been some easing of these restrictions, currently there are many limits on where electric bikes can be used off of pavement.

There is also controversy among many mountain bike riders who do not see the benefits of e-bikes and do not want them on trails. The primary concern is that e-bikes could cause more damage to trails than traditional mountain bikes and, as a result, all bikes may be banned from certain trails. However, that stance could be changing.  Just last year, the International Mountain Bicycling Association updated its position on e-mountain bikes, indicating that the sport’s largest advocacy group will now support e-bike access to certain trails.

Beyond e-bikes is another revolutionary development in the modern bicycle.  CeramicSpeed is a bicycle bearing manufacturer who partnered with the University of Colorado Mechanical Engineering Department to create what has been billed as the most efficient bicycle drive train ever invented.  Called DrivEn, this bicycle drive system looks nothing like the conventional systems that have been used in the past.

DrivEn utilizes pedals to power the drive train, but there is no chain or derailleurs, which are all part of traditional systems.  The problem with current bike drive trains is that the chain and derailleurs create eight friction points at which efficiency is lost.  According to CeramicSpeed, Driven creates 49 percent less friction when compared to the market leading chain and derailleur drivetrain. DrivEn eliminates the eight points of friction that plagues traditional drive trains and replaces them with four that rotate on ceramic bearings.

CeramicSpeed accomplishes this efficiency by using 21 bearings, a drive shaft (in lieu of a chain), and a 13-speed rear cog. The teeth of the single chain ring, powered by the pedals, engage the cassette cogs. As the rider pedals, the bearings’ low friction allows them to transfer torque from the drive shaft into the rear wheel at 99 percent efficiency. The low friction design allows for greater speeds for riders with less energy exerted.

Image by stormautomobile from Pixabay

It is important to note that DrivEn is a prototype system.  Many of the details of the design beyond the drive system have not been worked out as of yet.  But the evolution beyond the traditional bike drive system, which had remained unchanged for decades, is exciting. “CeramicSpeed has proudly accomplished what many have said couldn’t be done,” says company CTO Jason Smith. “We achieved a 99-percent efficient multi-speed drivetrain while eliminating the chain and complex rear derailleur.”

New technology can transform older products into much more viable solutions.  The humble bicycle has been transformed by electric power and engineering breakthroughs.  These exciting advances will help people of all riding abilities and afford many who could not ride due to injuries or disabilities the opportunity to get back on their bikes.  Older riders can travel further or on more difficult surfaces.  All of this will be accomplished on clean, reliable bicycles that will benefit everyone thanks to scientific innovation.

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