This bike build starts with a mountain bike frame and the parts from the hoverboard are added to it piece by piece. The two motors are mounted to the frame and drive the front chain ring of the bike, allowing it to still take advantage of the bike’s geared drivetrain. Battery packs from two hoverboards were combined into a single battery which give the bike a modest 6-10 km of range depending on use. But the real gem of this build is taking the gyroscopic controller board from the hoverboards and converting it, with the help of an Arduino Due, to an ebike controller.
Eventually a battery pack will be added to give the bike a more comfortable range, but for now we appreciate the ingenuity that it took to adapt the controller from the hoverboard into an ebike controller complete with throttle and pedal assist. For other household objects turned into ebikes, be sure to check out one of our favorites based on a washing machine motor: the Spin Cycle.
Generally, monowheels are that wacky, wildly futuristic transport that we lump in the same category as hoverbikes and jetpacks: strange, currently impractical, but very cool. Not content with waiting for the distant future, [Sam Barker] made his own electric monowheel. (Video, embedded below.)
The hardest part of any monowheel is that the outside rim needs to stand enormous abuse. It supports the weight of the vehicle and provides most of the structural integrity, but also is the means of propulsion. [Sam]’s first thought was to use a trampoline frame as it is a round and reasonably sturdy tube steel. He 3D printed the rollers that connected the subframe to the trampoline frame. Flat bar stock was used to make the angles inside the subframe and straight tube steel connected the inner frame into a trapezoid. The trampoline frame was welded together and on the first test spin, it broke apart from the stress. It simply wasn’t strong enough.
Not to be dissuaded, he found a company that bends steel into custom shapes. He stole the e-bike kit from another bike he had converted earlier, and the wheel was turning. Some handles and foot-pedal later, it was time for a proper test drive. Overall, the result is pretty impressive and the double-takes [Sam] gets while riding down streets in town are wonderful. If you’re looking to scratch the monowheel itch, check out this wooden monowheel.
It may not look like it in some parts of the world, but electric vehicles are gaining more and more market share over traditional forms of transportation. The fastest-growing segment is the e-bike, which some say are growing at 16x the rate of conventional bikes (which have grown at 15% during the pandemic). [Jacques Mattheij] rides an S-Pedelec, which is a sort of cross between a moped and an e-bike. There were a few downsides, and one of those was the pitiful range, which needed to be significantly upgraded.
The S-Pedelec that [Jacques] purchased is technically considered a moped, which means it needs to ride in traffic. The 500 watt-hour battery would only take him 45km (~28 miles) on a good day, which isn’t too bad but a problem if your battery runs down while in traffic, struggling to pedal a big heavy bicycle-like thing at car speed. You can swap batteries quickly, but carrying large unsecured extra batteries is a pain, and you need to stop to change them.
There were a few challenges to adding more batteries. The onboard BMS (battery management system) was incredibly picky with DRM and fussy about how many extra cells he could add. The solution that [Jacques] went with was to add an external balancer. This allowed him to add as many cells as he wanted while keeping the BMS happy. The battery geometry is a little wonky as he wanted to keep the pack within the frame. Putting it over the rear wheel would shift the center of gravity higher, changing the bike’s handling. After significant research and preparation, [Jacques] welded his custom battery back together with a spot welder. The final capacity came in at 2150wh (much better than the initial 500wh). An added benefit of the extra range is the higher speed, as the bike stays in the higher voltage domain for much longer. In eco mode, it can do 500km or 180km at full power.
It’s awe-inspiring, and we’re looking forward to seeing more e-bikes in the future. Maybe one day we’ll have tesla coil wireless e-bikes, but until then, we need to make do with battery packs.
[Mark Havran] is on a mission to complete a solo trip around the world on his bicycle. For such a long and arduous trip, unsupported by anything other than what he and his bike can carry, he has devised a unique vehicle with everything he needs to accomplish his journey. This bike has plenty of things we’ve seen before, such as solar panels and an electric motor, but plenty of things that are completely novel as well.
For such long-distance trips, the preferred style of bike for most is a recumbent. This allows the rider to take a more relaxed position while riding and is much more efficient than an upright bike as well. [Mark]’s bike also uses a hub motor in the front wheel powered by a set of lithium ion battery packs. The bike also utilizes four solar panels with three charge controllers (to reduce the impacts of panel shading) laid out with three of the panels on a trailer and a single panel above the bike to give him some shade while riding. [Mark] also built solar tracking abilities into each of the two arrays, allowing the solar panels to automatically rotate around the trailer and bike to more efficiently capture sunlight than a statically-mounted set of panels would be able to. They can also be manually controlled in case of high winds.
From the video linked below, we can see a number of other added features to the bike that will enable it to make such a long trip. First, he is getting a new motor which has a number of improvements over his old one, which he put over 30,000 kilometers on. Second, there are some safety features that deserve a mention such as his lighting setup borrowed from emergency response vehicles, and even includes a fire extinguisher for any catastrophic electrical failures. Of course, if you aren’t optimizing your recumbent electric bike for long distance there are some other modifications you could make to it as well to improve its off-road abilities. Best of luck, Mark!
Some bicycles are built primarily for practicality, while others are more focused on novel looks. [Make It Extreme]’s latest project, the extending bicycle, falls squarely in the latter category.
Built around four custom-machined pneumatic pistons, this electric bike can lift the rider about a meter into the air with the flick of a switch. The front pair forms the bicycle’s forks, while the rear pair is mounted between the frame and swingarm. A small onboard compressor is used to charge a pair of modified fire extinguishers, which feed the pistons via pneumatic valves mounted on the handlebars. The wheels and brakes were scavenged from an old scooter. Since the length between the crankset and rear wheel never changes, there is no need to struggle with chain tensioners as the ride height changes.
While we would hate to face-plant from that height, it certainly looks like a fun ride and conversation starter. This is the case for many of [Make It Extreme]’s projects, like a ridable tank track and monowheel motorcycle.
[Dave Schneider] has been chasing an electric-bike build for more than 10 years now. When he first started looking into it back in 2009, the cost was prohibitive. But think of how far we’ve come with the availability of motors, electronic speed controllers, and of course battery technology. When revisiting the project this year, he was able to convert a traditional bicycle to electric-drive for around $200.
Electric skateboards paved the way for this hack, as it was an outrunner motor that he chose to use as a friction drive for the rear wheel. The mounting brackets he fabricated clamp onto the chain stay tubes and press the body of the motor against the tire.
The speed of the motor is controlled by a rocker switch on the handlebars, but it’s the sensors in the brake levers that are the neat part. Magnets added to each brake lever are monitored by hall-effect sensors so that the throttle cuts whenever it senses the rider squeezing the front brake (effectively free-wheeling the bike), while the rear brake triggers a regenerative braking function he’s built into the system!
Sure you can buy these bikes, you can even buy conversion kits, but it’s pretty hard to beat the $88 [Dave] spent on the motor when the cost of purpose-built motors is usually several times this figure. The rest is fairly straight-forward, and besides ordering batteries and an electronic speed controller, you likely have the bits you need just waiting for you in your parts bin.
Getting into e-biking is a great hobby. It can get people on bikes who might otherwise not be physically able to ride, it can speed up commute times, and it can even make hauling lots of stuff possible and easy, not to mention it’s also fun and rewarding. That being said, there are a wide array of conflicting laws around what your e-bike can and can’t do on the road and if you don’t want to run afoul of the rules you may need a programmable device that ensures your e-bike is restricted in the appropriate way.
This build is specifically for Bafang mid drives, which can be up to 1000 W and easily power a bike beyond the speed limit where [Tomblarom] lives. A small microcontroller is housed in a waterproof box on the bike and wired between the motor’s display and controller. A small hall effect sensor and magnet sit by this microcontroller, and if the magnet is removed then the microcontroller reprograms the bike’s controller to limit the speed and also to disable the throttle, another feature that is illegal in some jurisdictions but not others. As an added bonus, the microcontroller also handles brake lights, turn signals, and automatic headlights for the bike as well.
While the project page mentions removing the magnet while getting pulled over to avoid fines and other punishments, that’s on you. We imagine this could still be useful for someone who wants to comply with local laws when riding on the road, but still wants to remove the restrictions when riding on private property or off-road where the wattage and speed restrictions might not apply.