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?

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Power Steering Pump Repurposed for Great Speed

Electric bikes are getting a lot of attention lately. Pretty much anyone can buy a kit online and get a perfectly street legal ride with plenty of range. But if you don’t want to take the kit route, and you’d rather take a tack that will get you noticed more around these parts, take some notes from [Jule553648]’s recent build that definitely isn’t using any parts from a kit.

The motor from the build is an electric power steering pump from a junkyard car. This gets mounted on a one-off rear bike rack and drives the rear tire with help from some gears from a pocket bike gearbox from eBay. A lot of the parts in this build were designed and built using CAD and a machine shop, and the parts for the battery and the power controller were sourced via China to save on cost.

The whole build has a homemade vibe that we find irresistible. The bike can go 35 km/h on level ground without breaking a sweat and has about 40 km of range which is nothing to scoff at. It might even be street legal depending on the wattage of the motor and whether or not you live in Europe (where throttles are generally not allowed on electric bikes). If you’re lacking a machine shop, though, we featured a very well-built kit ebike a while back that you could use as a model to get your feet wet.

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Electric Bike From The Ground Up

Electric vehicles are getting more traction these days, but this trend is rolling towards us in more ways than just passenger vehicles. More and more bikes are being electrified too, since the cost of batteries has come down and people realize that they can get around town easily without having to pay the exorbitant price to own, fuel, and maintain a car. Of course there are turnkey ebikes, but those don’t interest us much around here. This ebike from [Andy] is a master class in how to build your own ebike.

Due to some health issues, [Andy] needed a little bit of assistance from an electric motor on his bike, but found out that the one he wanted wouldn’t fit his current bike quite right. He bought a frame from eBay with the right dimensions and assembled the bike from scratch. Not only that, but when it was time to put the battery together he sourced individual 18650 cells and built a custom battery for the bike. His build goes into great detail on how to do all of these things, so even if you need a lithium battery for another project this build might be worth a read.

If you’ve never been on an electric bike before, they’re a lot of fun to ride. They’re also extremely economical, and a good project too if you’re looking for an excuse to go buy a kit and get to work. You can get creative with the drivetrain too if you’d like to do something out of the box, such as this bike that was powered by AA batteries and a supercapacitor.

Row Your Bike To China

If you’re a fan of endurance racing motor vehicles, there’s one that puts the 24 Hours of Le Mans, the Dakar Rally, and the Baja 1000 to shame, and the race doesn’t even involve cars. Indeed, the vehicles used for this massive trek from France to China are electric bicycles, powered only by solar panels. This is the epic Sun Trip endurance race, and one of its competitors built a unique tandem bike that is powered both by pedaling, rowing, and the solar panels.

The tandem bike is interesting on its own since the atypical design uses a back-to-back layout which means one person is facing backward, but the storage space is dramatically increased over the normal forward-facing layout. The person in the rear doesn’t pedal, though. [Justin_le] built an upper-body-powered rowing station for that spot so that the person riding back there can rest their legs but still help propel the vehicle. Of course, there’s also a solar panel roof so the two riders can pedal and row in the shade, which includes MPPT and solar tracking which drives a small electric motor on board as well.

This race started in June but is still going on. There’s a live GPS feed so you can keep up with the teams, and if you get really inspired you can go ahead and sign up for the 2019 race as well. This particular bike was also featured on Radio Canada as well if you’d like to learn more about it.

Thanks to [Arthur] for the tip!

Pavement Projection Provides Better Bicycle Visibility at Night

Few would question the health benefits of ditching the car in favor of a bicycle ride to work — it’s good for the body, and it can be a refreshing relief from rat race commuting. But it’s not without its perils, especially when one works late and returns after dark. Most car versus bicycle accidents occur in the early evening, and most are attributed to drivers just not seeing cyclists in the waning light of day.

To decrease his odds of becoming a statistics and increase his time on two wheels, [Dave Schneider] decided to build a better bike light. Concerned mainly with getting clipped from the rear, and having discounted the commercially available rear-mounted blinkenlights and wheel-mounted persistence of vision displays as insufficiently visible, [Dave] looked for ways to give drivers as many cues as possible. Noticing that his POV light cast a nice ground effect, he came up with a pavement projecting display using four flashlights. The red LED lights are arranged to flash onto the roadway in sequence, using the bike’s motion to sweep out a sort of POV “bumper” to guide motorists around the bike. The flashlight batteries were replaced with wooden plugs wired to the Li-ion battery pack and DC-DC converter in the saddle bag, with an Arduino tasked with the flashing duty.

The picture above shows a long exposure of the lights in action, and it looks very effective. We can’t help but think of ways to improve this: perhaps one flashlight with a servo-controlled mirror? Or variable flashing frequency based on speed? Maybe moving the pavement projection up front for a head-down display would be a nice addition too.

Cheap and Easy Helmet Lights for the Kids

Bikes are a great way to get around and get exercise at the same time, and are widely popular with human children due to the fact that they’re generally not allowed to drive. However, riding on or next to the road can be dangerous, particularly at night, when even adults on bikes are hard to see. It’s far worse for the youngest children, who can be incredibly small and difficult to spot. [Patrick]’s children enjoy riding, but it can get a little sketchy at night, so he developed a solution.

The project relies on cheap, commonly available LED strip lights. Rather than any fancy addressable strips, these are just simple strings of LEDs with current limiting resistors already fitted in a convenient, adhesive backed format. This makes the job as easy as peeling off the backing tape, sticking the strips to the helmet, and providing a power source. In clsasic entry-level hack style, everything’s running off a single 9V battery. Is it as versatile as a rechargable lithium pack with integrated controller? No, but it’s a swift way to get a project off the ground.

The trick here isn’t so much the hardware side of things – there’s nothing fancy about a battery and some LEDs. The key here is that [Patrick] identified that his children are small and difficult to see, thus it made sense to fit helmet lights rather then more typical bike lights to make them more visible to surrounding traffic.

For something at the other end of the spectrum, check out this amazingly professional LED bike light.

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3D Printed Skateboard Mount for Bikes

[Matt Obal] had a problem. The local skatepark was too far to skateboard, but close enough to bike. Carrying a skateboard on a bicycle is a rather awkward (and unsafe) maneuver. [Matt’s] answer to the problem is Truck Stop, a bicycle mounted skateboard carrier he developed and is manufacturing himself.

[Matt’s] work on Truck Stop began about a year ago, with his purchase of a 3D printer. He designed a seat back mounted device that secures the skateboard by wedging between the truck and the board itself. The design is printed in PLA and is hollow. Truck Stop’s strength comes from being filled with resin and fiberglass cloth.

If you’ve worked with resin, you probably know that some formulas get hot while they harden. This caused a few melted prints until [Matt] figured out that a dunk in cold water at the right time would allow the resin to complete it’s hardening process while keeping the heat below the melting temperature of PLA. He’s since switched to a different resin formula that generates less heat.

[Matt] is selling the Truck Stop at his website, and spent quite a bit of time working on a silicon mold so he could cast as many mounts as he wanted. The problem was fiberglass poking through the final cast part. In the end, he decided to stick with the resin filled PLA of his prototypes.