Scratch Built Tricycle Maximizes Fuel Efficiency

While the bicycling community is welcoming an influx of electric bikes, there’s a group of tuners on the fringes that are still intent on strapping gas motors of all sizes to bicycles and buzzing down the roads in a loud and raucous fashion. Kits are readily available and are much cheaper than comparable e-bike kits, and with a little bit of work it’s possible to squeeze a lot of excitement from these small motors. With a lot of work, though, you might end up with something like this incredibly fuel efficient and fully customized reverse trike from [Paul Elkins].

The entire goal with this build was fuel efficiency, so the plan is to eventually enclose the vehicle in aerodynamic fairings, most likely using his favorite material, Coroplast. The frame itself is completely hand-made from square tube and welded by [Paul] himself to his own custom specifications. He bolts on a suspension and custom steering rack with levers to control the two front wheels, and the small engine and gas tank are attached to the back above the single drive wheel. The engine hadn’t been started in ten years, but once he got it all put together, it started right up and he was able to take his latest prototype out on the road for a test drive.

While the build isn’t completely finished, the video below (eleventh so far in the build log) is far enough along to show the fruits of years of [Paul]’s labor. It’s taken a while to get a design that worked like he wanted, but with this iteration, he finally has what he was looking for.

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Keep An Eye On Your Bike With This DIY GPS Tracker

Owning a bike and commuting on it regularly is a great way to end up with your bike getting stolen, unfortunately. It can be a frustrating experience, and it can be particularly difficult to track a bike down once it’s vanished. [Johan] didn’t want to be caught out, however, and thus built a compact GPS tracker to give himself a fighting chance to hang on to his ride.

It’s built around the Arduino MKR GSM, a special Arduino built specifically for Internet of Things project. Sporting a cellular modem onboard, it can communicate with GSM and 3G networks out of the box. It’s paired with the MKR GPS shield to determine the bike’s location, and a ADXL345 3-axis accelerometer to detect movement. When unauthorised movement is detected, the tracker can send out text messages via cellular connection in order to help the owner track down the missing bike.

The tracker goes for a stealth installation, giving up the deterrent factor in order to lessen the chance of a thief damaging or disabling the hardware. It’s a project that should give [Johan] some peace of mind, though of course knowing where the bike is, and getting it back, are two different things entirely. We’ve seen creative techniques to build trackers for cats, too. It used to be the case that such “tracking devices” were the preserve of movies alone, but no longer. If you’ve got your own build, be sure to let us know on the tipline!

 

 

Learning To Speak Peloton

Recently [Imran Haque]’s family bought the quite popular Peloton bike. After his initial skepticism melted to a quiet enthusiasm, [Imran] felt his hacker curiosity begin to probe the head unit on the bike. Which despite being a lightly skinned android tablet, has a reputation for being rather locked down. The Peloton bike will happily collect data such as heart rate from other devices but is rather reticent to broadcast any data it generates such as cadence and power. [Imran] set out to decode and liberate the Peleton’s data by creating a device he has dubbed PeloMon. He credits the inspiration for his journey to another hacker who connected a Raspberry Pi to their bricked exercise bike.

As a first step, [Imran] step began with decoding the TRRS connector that connects the bike to the head unit. With the help of a multi-meter and a logic analyzer, two 19200bps 8N1 RS-232 channels (TX and RX) were identified. Once the basic transport layer was established, he next set to work decoding the packets. By plotting the bytes in the packets and applying deductive reasoning, a rough spec was defined. The head unit requested updates every 100ms and the bike responded with cadence, power, and resistance data depending on the request type (the head unit did a round-robin through the three data types).

Once the protocol was decoded, the next step for [Imran] was to code up an emulator. It seems a strange decision to write an emulator for a device with a simple protocol, but the reasoning is quite sound. It avoids a 20-minute bike ride every time a code change needs to be tested. [Imran] wrote both an event-driven and a timing-accurate emulator. The former runs on the same board as the PeloMon and the latter runs on a separate board (an Arduino).

The hardware chosen for the PeloMon was an Adafruit Feather 32u4 Bluefruit LE. It was chosen for supporting Bluetooth LE as well as having onboard EEPROM. A level shifter allows the microcontroller to talk directly to the RS-323 on the bike. After a few pull requests to the Adafruit Bluetooth libraries and a fair bit of head-banging, [Imran] has code that advertises two Bluetooth services, one for speed and another for power. A Bluetooth serial console is also included for debugging without having to pull the circuit out.

The code, schematics, emulators, and research notes are all available on GitHub.

No-Battery Pressure Sensors For Bike Tyres

Finding out you’ve got a flat tyres halfway into a long ride is a frustrating experience for a cyclist. Maintaining the

While the epoxy does a great job of sealing the PCB to the valve extension, the overmoulding process would likely be key to producing a product with shelf-quality fit and finish. This test run was done with 3D printed ABS moulds.

correct tyre pressures is key to a good ride, whether you’re stacking up the miles on the road or tackling tricky single track in the mountains. [CaptMcAllister] has put together a device that makes keeping an eye on your tyres easy.

The device consists of an ultra low power microcontroller from Texas Instruments, paired with a pressure sensor. Set up for Near Field Communication, or NFC, it’s designed to be powered by the smartphone that queries the microcontroller for a reading. We featured a prototype back in 2015 which required mounting the device within the inner tube of the tyre itself. However, this required invasive installation and the devices tended to wear out over time due to flex damaging the delicate copper coil antenna.

The new design consists of the same microcontroller hardware, but mounted in a modified valve extension that fits to the fill valve of the bicycle tyre. The PCB is directly epoxied on to the valve extension, ensuring air can’t leak out over time. The assembly is then overmoulded in an injection moulding process to provide further sealing and protection against the elements. This should help immensely in rough-and-tumble mountain biking applications.

The new device provides a simple screw-on solution for tire pressure monitoring that’s set and forget — no batteries required. [CaptMcAllister] is currently investigating options for a production run, and given the simple design, we imagine it couldn’t be too hard to rattle off a few hundred or thousand units. We could imagine it would also pair well with a microcontroller, NFC reader, and a display setup on the handlebars to give live readings where required. We look forward in earnest to seeing where this project goes next!

Electric BMX With Friction Drive

Electric bikes have increased in popularity dramatically over the past few years, and while you can easily buy one from a reputable bicycle manufacturer, most of us around here might be inclined to at least buy a kit and strap it to a bike we already have. There aren’t kits available for every bike geometry, though, so if you want an electric BMX bike you might want to try out something custom like [Shea Nyquist] did with his latest build. (Video, embedded below.)

BMX frames have a smaller front triangle than most bikes, so his build needed to be extremely compact. To that end, it uses two small-sized motors connected together with a belt, which together power a friction drive which clamps against the rear tire to spin it directly. This keeps the weight distribution of the bike more balanced as well when compared to a hub drive, where the motor is installed in the rear wheel. It also uses a more compact lithium polymer battery pack instead of the typical 18650 lithium ion packs most e-bikes use, and although it only has a range of around three miles it’s more than enough charge to propel it around a skate park.

The build boasts impressive numbers too, at 2.5 kW peak power per motor. This puts it in electric motorcycle territory, and it’s indeed fast despite its small stature. For a true high speed e-bike experience, though, you’ll need a slightly larger frame and motor even if it means tossing safety out of the window. Continue reading “Electric BMX With Friction Drive”

RGB Party Bike Flashes With The Beat

One of the biggest dangers to a cyclist is not being seen at night. To counteract this, all manner of lighting and reflective gear is available to help ensure bicycles are seen on the streets. Of course, you don’t have to stop at the purely practical. [TechnoChic] decided to have some fun with her ride, festooning her party bike with many, many LEDs.

As you’d expect, the RGB illuminations are thanks to WS2812B LED strips. Running the show is  a trio of Arduino Nano 33 IoTs – one for the LEDs on the bike’s frame, the other two mounted on the front and back wheels respectively. This allowed for the easy control of LEDs on the spokes without having to pass data and power lines to the rotating wheels. The LEDs on the frame are even music-reactive, with the Arduino sampling music input via one of its analog-to-digital converters.

Paired with a boombox on the bike, the build makes for a great way to hype up group rides through the city at night. We can imagine such a bike being an absolute hit at Critical Mass, though you’ve probably gotta add a laser or glitter cannon if you’re going to draw attention at Burning Man. If you’re tired of pedaling, you might consider an electric conversion, too. Video after the break.

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Bike Computer Powers On Long After Your Legs Give Out

A typical bicycle computer from the store rack will show your speed, trip distance, odometer, and maybe the time. We can derive all this data from a magnet sensor and a clock, but we live in a world with all kinds of sensors at our disposal. [Matias N.] has the drive to put some of them into a tidy yet competent bike computer that has a compass, temperature, and barometric pressure.

The brains are an STM32L476 low-power controller, and there is a Sharp Memory LCD display as it is a nice compromise between fast refresh rate and low power. E-paper would be a nice choice for outdoor readability (and obviously low power as well) but nothing worse than a laggy speedometer or compass.

In a show of self-restraint, he didn’t try to replace his mobile phone, so there is no GPS, WiFi, or streaming music. Unlike his trusty phone, you measure the battery life in weeks, plural. He implemented EEPROM memory for persistent data through power cycles, and the water-resistant board includes a battery charging circuit for easy topping off between rides.

When you toss the power of a mobile phone at a bike computer, someone will unveil the Android or you can measure a different kind of power from your pedals.

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