Cheating The Perfect Wheelie With Sensors And Servos

Everyone remembers popping their first wheelie on a bike. It’s an exhilarating moment when you figure out just the right mechanics to get balanced over the rear axle for a few glorious seconds of being the coolest kid on the block. Then gravity takes over, and you either learn how to dismount the bike over the rear wheel, or more likely end up looking at the sky wondering how you got on the ground.

Had only this wheelie cheating device been available way back when, many of us could have avoided that ignominious fate. [Tom Stanton]’s quest for the perfect wheelie led him to the design, which is actually pretty simple. The basic idea is to apply the brakes automatically when the bike reaches the critical angle beyond which one dares not go. The brakes slow the bike, the front wheel comes down, and the brakes release to allow you to continue pumping along with the wheelie. The angle is read by an accelerometer hooked to an Arduino, and the rear brake lever is pulled by a hobby servo. We honestly thought the servo would have nowhere near the torque needed, but in fact it did a fine job. As with most of [Tom]’s build his design process had a lot of fits and starts, but that’s all part of the learning. Was it worth it? We’ll let [Tom] discuss that in the video, but suffice it to say that he never hit the pavement in his field testing, although he appeared to be wheelie-proficient going into the project.

Still, it was an interesting build, and begs the question of how the system could be improved. Might there be some clues in this self-balancing motorized unicycle?

8 thoughts on “Cheating The Perfect Wheelie With Sensors And Servos

  1. I think he could make it work with different riders and arm positions if he just included a wheel position / speed sensor so it could detect when the bike center of gravity was moving forward or backward.

  2. Audi did a e-bike in 2016 for their car show. it was an BMX with built-in wheelie-helper. An accelerometer was used to control the motor speed. For the Press there was an Audi Employee wearing a SUIT doing wheelies. kinda funny. later they did a preffesional e-bike but i couldn’t find any mentioning of the wheelie thingy. Kinda sad. good that someone else is continuing the work. maybe it goes mainstream this time

  3. By watching the video I was left with the ideia that he did not know how to program Arduino enough, and did not want to go deeper into it. Seems like he implemented a ‘0/1’ behavior, without considering anything else like overshooting, brake force or response time. A great idea but quick and dirty implementation.

  4. I think he’s only using an accelerometer to measure angle but he really needs a gyro too. The forces due to his pumping the pedals is adding “noise” to his gravity coordinate system that he’s using to measure the tilt angle.

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