Automatic Arduino Bicycle Shifter

One of the keys to efficient cycling performance is a consistent pedalling cadence. To achieve this the cyclist must always be in the correct gear, which can be tricky when your legs are burning and you’re sucking air. To aid in this task, [Jan Oelbrandt] created Shift4Me, an open-source Arduino powered electronic shifter.

The system consists of a hall effect sensor at the pedals to measure cadence, an Arduino controller, and a servo mechanism to replace the manual shifter. Everything is mounted in a small enclosure on the frame. The only way to get one is to build your own, so a forum is available for Shift4Me builders, where the BOM, instructions, code and other documentation is available for download. Most bikes should be easy to convert, and [Jan] invites builders to post their modifications and improvements.

Since the only input is the cadence sensor, we wonder if the system will interfere more than help when the rider has to break cadence. It does however include allowance to hold on the current gear, or reset to a starting gear by pushing a button. One major downside is that you will be stuck in a single gear if the battery dies since the manual shifter is completely removed.

As one of the oldest continuously used forms of mechanical transport, there is no shortage of bicycle-related hacks. Some of the more recent ones we’ve seen on Hackaday include e-bike with a washing machine motor, and a beautifully engineered steam-powered bicycle.

3D Printed Bike Shifter

Shifter

[Rich] is embarking on a fairly long bike trip in a few weeks – Seattle to Portland – and thought including some 3D printed gear on his ride would be a fun endeavor. His first idea was a printed belt drive, but the more he looked at that idea the less realistic it seemed. He finally hit upon the idea of creating a 3D printed bike shifter, and after an afternoon of engineering and printing, the shifter ended up working very well.

[Rich]’s shifter is actually a friction shifter. Instead of ‘clicking’ into position, this type moves the┬áderailleur gradually. It’s much more tolerant of slight misalignment, and most touring bikes – the type that would embark on long journeys along the coast of the Pacific northwest – have these types of shifters.

Total printing time was about one and a half hours, and was attached to [Rich]’s bike with off-the-shelf hardware. He’s already put about 150 miles on his custom designed shifter with no signs of failure.