Developing An Open Source Bike Computer

January 6, 2023 by Bryan Cockfield 45 Comments

While bicycles appear to have standardized around a relatively common shape and size, parts for these bikes are another story entirely. It seems as though most reputable bike manufacturers are currently racing against each other to see who can include the most planned obsolescence and force their customers to upgrade even when their old bikes might otherwise be perfectly fine. Luckily, the magic of open source components could solve some of this issue, and this open-source bike computer is something you’ll never have to worry about being forced to upgrade.

The build is based around a Raspberry Pi Zero in order to keep it compact, and it uses a small 2.7 inch LCD screen to display some common information about the current bike ride, including location, speed, and power input from the pedals. It also includes some I2C sensors including pressure and temperature as well as an accelerometer. The system can also be configured to display a map of the current ride as well thanks to the GPS equipment housed inside. It keeps a log in a .fit file format as well so that all rides can be archived.

When compared against a commercial offering it seems to hold up pretty well, and we especially like that it’s not behind a walled garden like other products which could, at any point, decide to charge for map upgrades (or not offer them at all). It’s a little more work to set up, of course, but worth it in the end. It might also be a good idea to pair it with other open source bicycle components as well.

Thanks to [Richard] for the tip!

Replace Your Automatic Transmission With A Bunch Of Relays

January 5, 2023 by Dan Maloney 78 Comments

A “Check Engine” light on your dashboard could mean anything from a loose gas cap to a wallet-destroying repair in the offing. For [Dean Segovis], his CEL was indicating a fairly serious condition: a missing transmission. So naturally, he built this electronic transmission emulator to solve the problem.

Some explanation may be necessary here. [Dean]’s missing transmission was the result of neither theft nor accident. Rather, he replaced the failed automatic transmission on his 2003 Volkswagen EuroVan with a manual transmission. Trouble is, that left the car’s computer convinced that the many solenoids and sensors on the original transmission weren’t working, leaving him with a perfectly serviceable vehicle but an inspection-failing light on the dash.

To convince the transmission control module that a working automatic was still installed and clear the fourteen-odd diagnostic codes, [Dean] put together a block of eight common automotive relays. The relay coils approximate the resistance of the original transmission’s actuators, which convinces the TCU that everything is hunky dory. There were also a couple of speed sensors in the transmission, which he spoofed with some resistors, as well as the multi-function switch, which detects the shift lever position. All told, the emulator convinces the TCU that there’s an automatic transmission installed, which is enough for it to give the all-clear and turn off the Check Engine light on the dash.

We love hacks like this, and hats off to [Dean] for sharing it with the VW community. Apparently the issue with the EuroVan automatic transmissions is common enough that a cottage industry has developed to replace them with manuals. It’s not the only questionable aspect of VW engineering, of course, but this could help quite a few people out of a sticky situation.

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A Bicycle Trailer Fit For Heavy Haulage

January 2, 2023 by Jenny List 7 Comments

One of the problems of being a cyclist is that a bicycle just isn’t designed to carry much more than a human. You can get panniers and hang shopping bags from the handlebars, but sooner or later there’s a load which just doesn’t fit. At that point there’s only one way forward that involves staying on two wheels: find a bike trailer. If you fancy building one yourself, then there’s La Charette (French language, Google Translate link), an open-source three-wheeler design from France.

Construction is a sturdy welded box section tube spaceframe, with the single wheel at the front providing steering, and a towing bar attached to the seat post of the bicycle. Along with the impressive load capacity comes the problem of towing it, and for the cyclist with less-than-superhuman strength there’s the option of an electrically-driven front wheel. Stopping the whole thing is an essential feature with loads this size, and to that end there’s an inertial braking system operated by the force on the towing bar.

All in all it appears to be a useful trailer, albeit on the large side for storage when not being used. It’s certainly one of the larger bike trailers we’ve seen, though not perhaps the most stylish.

Thanks [Jeff] for the tip!

Snow Plowing By Bicycle

January 1, 2023 by Bryan Cockfield 44 Comments

There are few challenges more difficult or dangerous than trying to get around the majority of North American cities by bicycle. Not only is the bicycle infrastructure woefully inadequate for safe travel (if it exists at all), but it’s often not maintained to any reasonable standard, either. This goes double in colder areas, where bike paths can essentially become abandoned in the winter after a snowfall. [Phil] found himself in this situation recently after a snowfall in western Canada and decided to DIY his own bike-powered snowplow to help keep his bike paths cleared.

The plow is built around an electric-assisted cargo bicycle, which is almost as rare in North America as bicycle infrastructure itself, but is uniquely suited to snowplow duty. It has a long wheelbase and a large front cargo area that can be weighed down if needed to ensure the plow makes good contact with the ground. The plow itself is built out of sections of plastic 55-gallon drums, which have been cut into two scooping sections and attached to the bike with a wooden 2×4 frame. The plow can be raised or lowered with a ratchet strap mechanism, and the plastic scoop skips over bumps in the path with relative ease.

With this relatively simple mechanism attached to his bike, [Phil] can make sure the trails that he frequents around Vancouver are more suitable for bike travel in the winter. Riding a bicycle through the winter, even in the coldest of climates, is not that difficult with the right support and investment in infrastructure, and this build is the best DIY solution we’ve seen to bicycle infrastructure support outside of adopting something like this remote-controlled snowblower to the job.

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A simple wooden chair with mint metallic connectors at the corners sits next to a pile of wooden pieces wrapped in leather and straps to form a backpack.

A Nomadic Chair

December 29, 2022 by Navarre Bartz 21 Comments

There’s no shortage of different types of folding or portable chairs, but designer [Jorge Penadés] built a backpack chair that will go the long haul.

Furniture that assembles without screws or glue is always intriguing, and this chair fits the bill. Using simple metal connectors and joinery, it can be setup and taken down in about two minutes without the flimsy feeling of a bag chair. With a natural finish on the wood, the connectors give a nice pop of color without feeling overwhelming. There are even some pictures of a couch version if you follow the link.

In backpack mode, the pieces are held together by leather patches and ratchet straps. [Penadés] was focused on portability over comfort with this piece, but we think this connection method could be used in the future for more comfortable furniture that is still portable.

If you’re looking for more interesting furniture, checkout this Tambour Table with a Puzzling Secret or these CNC-able Seats.

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Chainless “Digital Drive” Bikes Use Electric Power Transmission Instead

December 23, 2022 by Lewin Day 140 Comments

We’re all familiar with how regular bikes work, with the pedals connected to the rear wheel via a simple chain drive. This setup is lightweight, cheap, and highly efficient. It’s not the only way to drive a bike though, and there’s plenty of buzz around the concept of “digital drive” bikes.

These drivetrains rely on electrical methods to transfer power in place of mechanical. The pedals are used to turn an electric generator, with power then sent to an electric motor which drives the rear wheel. The concept may sound overly complicated, but it does offer some benefits. The generator can change its operation to keep the rider pedalling at their most efficient, consistent rate. There would also be no chain to fall off, get snagged on clothing, or require regular maintenance.

It would make integrating regenerative braking possible, too, allowing the bike to harvest energy when going downhill too. This could be achieved with a storage battery or supercapacitor. As a bonus, it would be very easy to integrate power assist for the rider when tackling tough hills, for example. The lack of requirement for direct mechanical power transfer also means that there’s far more flexibility to design a bike with interesting geometry.

Such drive systems do give up some efficiency, however. All the power conversions between mechanical and electrical energy mean that a “digital drive” would likely only be 58% efficient. This compares poorly to the roughly 95% efficiency of power transfer in regular mechanically-driven bikes. There’s also a weight penalty, too.

Presnetly, there’s only one “digital drive” bike on the market – known as the Mando Footloose. It’s a swooping, folding, futuristic design, that has some feel issues when it comes to pedalling. And, given the added complexity and expense of these systems, it’s unlikely regular bikes or e-bikes are going away any time soon. Regardless, it’s fun to think about the potential for other drivetrain concepts to change the way we cycle. Video after the break.

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Hyundai To Lead US Market For Hydrogen Fuel Cell Trucks

December 13, 2022 by Lewin Day 96 Comments

Hydrogen has long been touted as a potential fuel of the future. While it’s failed to catch on in cars as batteries have taken a strong lead, it still holds great promise for larger vehicles like trucks.

Hyundai have been working diligently in this space over the last few years, with its Xcient line of fuel-cell powered trucks. It’s set to dominate the world of hydrogen trucking in the US as it brings a fleet of vehicles to California next year.

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