bicycle

221 Articles

Two men in black shirts stand between a white and a blue exercise bike sitting on a table in front of them. The exercise bikes have black drums slightly larger than a coffee can affixed to the front of the bike which houses the shredding mechanism. In the background is a "Precious Plastics Torino" circular logo.

Getting Shredded Plastic…and Legs

September 23, 2023 by 10 Comments

While electric motors have taken the drudgery out of many tasks, human power has its advantages. [Precious Plastic Torino] has developed a human-powered plastic shredder for those times when an electric motor just won’t do.

Designed primarily for educational purposes at venues where electricity can be difficult to source, but also useful for off-grid environments, this exercise bike-based shredder can take small pieces of plastic and shred them into tiny pieces suitable for use with any of the other machines in the Precious Plastics ecosystem like their injection molding machine. As with all [Precious Plastics] projects, the files are will be open source; however, there is a six month exclusivity period for Patreon subscribers to help fund development efforts.

The build is relatively simple: take an old exercise bike, remove the unnecessary bits, and run the chain up to drive a shredding mechanism mounted on the front of the bike. We think they should’ve kept the flywheel to help keep the momentum going while shredding but can’t fault them for wanting to keep the prototype as simple as possible. Maybe the next step is getting these in spin classes around the country so people can get their exercise and help recycle in their community at the same time!

If this shredder doesn’t suit your fancy, maybe recycle your plastic with SHREDII or this other DIY effort. If you’d rather generate electricity on your exercise bike, then try building this bike generator.

Continue reading “Getting Shredded Plastic…and Legs” →

A silver front loader cargo bike sits in a parking lot in front of an electric vehicle charger. A cable runs from the charger to the bike.

Fast Charging A Cargo Bike From An Electric Car Charger

September 18, 2023 by 15 Comments

Fast charging is all the rage with new electric cars touting faster and faster times to full, but other EVs like ebikes and scooters are often left out of the fun with exceedingly slow charging times. [eprotiva] wanted to change this, so he rigged up a fast charging solution for his cargo bike.

Level 2 electric vehicle chargers typically output power at 7 kW with the idea you will fill up your electric car overnight, but when converted down to 60 V DC for a DJI Agras T10 battery, [eprotiva] is able to charge from 20% to 100% capacity in as little as 7 minutes. He originally picked this setup for maxing the regen capability of the bike, but with the high current capability, he found it had the added bonus of fast charging.

The setup uses a Tesla (NACS) plug since they are the most plentiful destination charger, but an adapter allows him to also connect to a J1772 Type 1 connector. The EV charging cable is converted to a standard 240 V computer cable which feeds power to a drone charger. This charger can be set to “fast charge” and then feeds into the battery unit. As an added bonus, many chargers that do cost money don’t start charging until after the first five minutes, so the bike is even cheaper to power than you’d expect.

For some reason, you can watch him do this on TikTok too.

If you too want to join the Personal EV Revolution, be sure to checkout how to choose the right battery for your vehicle and a short history of the Segway.

A silver and black bike sits in front of a dark grey bridge. It is on a hard surface next to green grass. The bike has a large basket area in front of the steering tube that then connects to the front wheel which is at the other end of the basket from the handlebars. It is best described as a long john bike, but is a more modern take on it than the wooden box Dutch bike.

Building A Cargo Bike Dream

September 12, 2023 by 54 Comments

Cargo bikes can haul an impressive amount of stuff and serve as a car replacement for many folks around the world. While there are more models every year from bike manufacturers, the siren song of a custom build has led [Phil Vandelay] to build his own dream cargo bike.

The latest in a number of experiments in hand-built cargo bike frames, this electrified front-loader is an impressive machine. With a dual suspension and frame-integrated cargo area, this bike can haul in style and comfort. It uses a cable steering system to circumvent the boat-like handling of steering arm long john bikes and includes a number of nice touches like (mostly) internal cable routing.

The video below the break mostly covers welding the frame with [Vandelay]’s drool-worthy frame jig, so be sure to watch Part 2 of the video for how he outfits the bike including the internal cable routing and turning some parts for the cable steering system on the lathe. If you get an urge to build your own cargo bike after following along, he offers plans of this and some of his other cargo bike designs. [Vandelay] says this particular bike is not for the beginner, unlike his previous version built with square tubing.

Looking for more DIY cargo bikes? Checkout this Frankenbike, another front loader, or this Russian trike.

Continue reading “Building A Cargo Bike Dream” →

Rubber Tracked Bicycle Is Horribly Inefficient

June 29, 2023 by 31 Comments

Wheeled bikes are efficient machines, and most cycling speed and distance records are held by them. However, [The Q] has a taste for weirder creations that amuse perhaps more than they serve as viable transportation. His latest experiments revolve around tracked propulsion methods.

The build is a wheelless bike that relies on long thin tracks mounted to a mountain bike frame. The tracks carriers are fabricated using steel box section fitted with cogged rollers. The tracks themselves are made using a pair of bicycle chains joined with welded steel bars. They’re fitted with slices of rubber cut out of traditional bike tires for grip. The rear track is driven from the bike’s pedals, while the front is merely left to run freely.

By virtue of its wide, flat tracks, the bike actually stands up on its own. It’s capable of riding in a straight line at slow speed, albeit relatively noisily. Steering is limited by virtue of the flat tracks, which don’t operate well at an angle to the ground. Since the tracks only contact the ground at a point, too, the bike has very high ground pressure, which would make it likely to sink into anything less solid than asphalt.

The build is relatively similar to [The Q]’s previous efforts to build a supposedly square-wheeled bike. What we’d really love to see at this point is a tracked bicycle that actually made the best of the technology – by being both swift and capable of crossing soft, marshy terrain. Video after the break.

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A Bicycle Powered By A Different Kind Of Eddy

May 16, 2023 by 31 Comments

When you think of a bicycle and an Eddy, you’d be forgiven for thinking first of Eddy Merckx, one of the most successful competitive cyclists to ever live. But this bicycle, modified by [Tom Stanton] as shown in the video below the break, has been modified by ditching its direct drive gearing in favor of using the friction-like eddy currents between magnets and copper to transfer power to the wheel.

Before even beginning to construct a mechanism for powering the bicycle, [Tom] had to figure out the basics: what kind of materials could be used for a metal disk? The answer, after much testing, turned out to be copper. What kind of magnets work best, and in what formation? Expensive high grade, aligned North to South pole for added eddy-dragging goodness. Would the mechanism work with any efficiency?

The end result is interesting to watch, and it’s not exactly as you’d have expected. Yes, eddy currents drive the copper hub, but at a 100 RPM difference. Where does all of that energy go? Hint: not to the wheel, and certainly not into propelling the bicycle. All in all it’s a fantastic experiment with unpredictable results.

If bicycle based bumbling about bakes your biscuits, you might appreciate this tennis-ball-enhanced ride too.

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The Bicycle (and More) Explained

May 8, 2023 by 25 Comments

They say a picture is worth a thousand words, but an animation, then, must be worth a million. Make that animation interactive, and… well, we don’t know how many words it is worth, but it is plenty! That’s the idea behind [Bartosz Ciechanowski’s] blog where he uses clever interactive animations to explain the surprisingly complex physics of riding a bicycle.

The first animation lets you view a rider from any angle and control the rider’s pose. Later ones show you how forces act on the rider and bicycle, starting with example wooden boxes and working back up to the original bike rider with force vectors visible. As you move the rider or the bike, the arrows show you the direction and magnitude of force.

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Square-Wheeled Bike Is Actually An Amazing Tracked Build

April 13, 2023 by 31 Comments

The invention of the wheel is considered one of the crowning achievements of early humanity. Squares don’t roll, after all. [The Q] decided to build a square-wheeled bike anyway, with a neat tracked setup that makes for an awesome visual gag.

The wheels are made out of C-angle steel, making them both stout and incredibly heavy. While they don’t really need the additional structure for strength, they feature spokes which mount a central hub for attaching the “wheels” to a bicycle axle. The squares aren’t designed to roll, though. Instead, they are fitted with gears and rollers, upon which a track made of bicycle chain and tires is fitted. When the rider pedals, this turns the track, propelling the bike along. Cleverly, the track mechanism is neatly hidden by some framing, confusing passers-by.

The riding experience is noisy, thanks to the tracks. There’s also plenty of rolling resistance. It’s unlikely bikes like these will become mainstream transport anytime soon, nor will you see them at the velodrome. Regardless, it’s certainly a great way to turn heads at the park.

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