If you’ve got a bike, there’s a good chance it’s set up with a derailleur at the rear and a bunch of gears to help you cycle more efficiently. And while that derailleur might be controlled by cables, hydraulics or even electronics, it’s usually down to you to set it in the right place. However, there was once a push to bring automatic gear shifting to bikes.
That’s right, while you might think the current crop of bike innovations is excessive, it ain’t got nothing on the ridiculous stuff bike designers were pulling in the early 2000s.
This incredible but wholly excessive piece of kit was brought to our attention by the good folks over at the Global Cycling Network, who inadvertently uncovered the automatic shifting bike in a budget bike challenge. So impressed were they by the tech, that they subsequently did a deep dive into how it all works, and it is fascinating.
The automatic shifter that they found was fitted to a bike from American brand LandRider, which sadly went out of business back in 2016. To shift between gears, the automatic derailleur doesn’t use electronics, however, and instead relies on weights and belts to change between the gears depending on your input. As GCN explains:
The system relies on a plastic disc fitted behind the cassette, and this disc has a belt fitted around it that is connected to a small gear on the rear of the derailleur. The derailleur itself has two small counterweights that are fixed to the gear the belt is driving.
As you ride faster and faster, these counterweights get pulled apart by the centrifugal force exerted on them. The parallelogram of the derailleur is connected to the internal section of the counterweights, as the weights separate and get pulled apart. This has the effect of pulling the cage over and shifting down into a smaller cog, allowing the rider to pedal at a fixed cadence.
As you slow down the force on the weights decreases and therefore the spring in the derailleur can overcome the centrifugal force of the weights, allowing a downshift to happen.
Despite its ingenuity, the automatic shifting never really took off in the world of cycling. That’s maybe because simple issues like snapped belts could render the derailleur totally useless. There were also issues with rapidly changing gears as you got to the bottom of a hill, as this could catch the derailleur out and jam.
Now, with electronic gearing sweeping across the cycling world, it feels like automatic shifting may never have another moment in the limelight. But what do you think, would you like to ride a bike that took the worries of what gear you should be in out of your hands? And have you ridden a bike that can shift like this, let us know in the comments below.