Death of the Derailleur, at the hands of the eBike
Could this possible rescue the bicycle industry?
The derailleur has been a bicycle-gear-shifting component in different forms for 130 years. From crude two-speed systems, to jewelry-esque parallelogram units from Campagnolo, it allowed riders to traverse more than just downtown 19th-century Paris by easily climbing hills with lower gears.
Today, though, the derailleur's days are numbered. Its death will come at the hands of ebikes. No, not because ebikes have the power to go up any hill in a single gear ratio, they have now enabled the use of CVT and auto/motorcycle-like, internal transmissions in mid-drive motors.
Who developed the first derailleur to allow a bicycle to shift between just two gears is debated. A few innovative designers in France and England battled to be the first in the 1890s with innovative designs. Those efforts were squashed, though, in the early 1900s by the durable and dependable Sturmey-Archer internally geared hubs. These were initially three speeds before they launched “wide-range” four-speeds 20 years later.
But it was Tullio Campagnolo in 1949 that brought us the modern-day, parallelogram derailleur. This revolutionized, quick, light, simple shifting and the design, although enhanced with clutches, electronics and exotic materials, exists to this day.
But to give the derailleur equipment to function, three, four, and now-13 gears are needed to be squeezed onto the rear hub between dished spokes and the chainstays. A chain needs to run through these gears. The chain needs to be lubed or waxed often, and it is open to the dirt, mud, rain and abuse the road and trail dishes out. The gears are exposed to the same elements and wear fast in this environment.
Motorcycles and autos use a system of interlocking gears and shafts altering the rotations between the input and output shafts. Scooters and some autos use continuously variable transmissions (CVT) with variable-diameter pulleys that seamlessly and continuously change gear ratios. Both systems are more complex than a derailleur, but service is extremely limited because they are housed in a sealed case and can run in a bath of clean, lubricating fluid.
Previously impossible in a bicycle application due to the size, weight and complexity, these styles of transmission began to be incorporated into bicycles. Nicolai introduced the G-Boxx in 2003, and Honda famously built the RN-01 G-Cross downhill race bike in 2004 to introduce motorcycle-style gearboxes to the world of pedals. But it was Pinion who mass commercialized their beautiful, geared internals for downhill racing platforms. Downhill was the perfect stage for the technology because weight and efficiency were less of an issue than durability and simplicity.
Now DJI-backed Avinox and future-forward, drive-system manufacturer Gobao are delivering eCVTs housed in mid-drive pedal-assist motors (MGUs). While they can be traditionally shifted with pre-set gear ratios, they can also actively and automatically alter the gear ratio to keep cadence constant at any speed.
While skeptics scoffed at this shift as a downhill novelty, now internal transmissions are making their way to the other bikes, driven by the ebike, mid-drive motors. It was relatively easy for ebike motor companies to package wide-range shifting into their existing mid-drive units. Now the gear changes could occur there instead of back at the rear wheel with a long-cage derailleur and a pie-plate size sprocket cassette squished into a dished rear wheel.
Housing the transmission within the mid-drive system also eliminates the need for a chain. Now the drive from the output shaft to the rear wheel can occur via a toothed belt. Belt drives are clean, quiet and nearly indestructible. They need no lubrication and eliminate 130 years of broken chains, maintenance, and grease-stained calves.
The new Avinox MG and Gobao X System will lead this revolution for e-mountain, e-gravel and electric hybrids. It won’t be long before we will likely see internally integrated transmissions on non-ebikes as automated manufacturing improves and weights come down even more.
Perhaps someday soon we’ll look at a SRAM eTap Red AXS derailleur like we do now with an old Campagnolo Simplex. The bicycle industry is not growing as it did in the twenty-teens, and history has shown us that significant innovations drive sales increases (remember suspension?). If internal, integrated transmissions do find their way to all bikes, this could be the shot in the arm our industry needs now.
