bicycle

224 Articles

Unicycle Given A Hand Crafted Gear Box

October 28, 2018 by 12 Comments

Being able to coast on a bicycle is a feature that is often taken for granted. The use of a freewheel was an improvement made early in the bicycle’s history, for obvious reasons. This also unlocked the ability to build bikes with multiple gears, allowing higher speeds to be easily reached. On a unicycle, however, there’s no chain and the pedals are permanently fixed to the wheel’s axle, meaning that there is (usually) no freewheel and no gearing. [johnybondo] wanted to get some more speed out of his unicycle, though, and realized he could do this with his own homemade internal geared hub for his unicycle.

The internal hub gear was machined and welded by hand as a one-off prototype. There are commercial offerings, but at $1700 it’s almost best to fund your own machine shop. It uses a planet gearset which is more compact than a standard gear, allowing it to fit in the axle. Once all the machining was done, it was time to assemble all of the gears into the hub, lace it to the wheel with spokes, and start pedaling away. Since it was so successful, he plans to build another and lace it to a larger wheel which will allow him to reach even higher speeds. If this isn’t fast enough for you, personally, there are other options available for ludicrous speed.

Now, this gear is still “fixed” in the sense that it’s a permanent gear ratio for his unicycle and it doesn’t allow him to shift gears or coast. There’s no freewheel mechanism so the unicycle can still be pedaled forward and backwards like a traditional unicycle. The advantage of this setup is that the wheel spins 1.5 times for every one revolution of the pedals, allowing him to more easily reach higher speeds.

DIY Arc Light Makes An Unnecessarily Powerful Bicycle Headlight

October 17, 2018 by 39 Comments

Remember when tricking out a bike with a headlight meant clamping a big, chrome, bullet-shaped light to your handlebar and bolting a small generator to your front fork? Turning on the headlight meant flipping the generator into contact with the front wheel, powering the incandescent bulb for the few feet it took for the drag thus introduced to grind you to a halt. This ridiculous arc-lamp bicycle headlight is not that. Not by a long shot.

We’re used to seeing [Alex] doing all manner of improbable, and sometimes impossible, things on his popular KREOSAN YouTube channel. And we’re also used to watching his videos in Russian, which detracts not a whit  from the entertainment value for Andglophones; subtitles are provided for the unadventurous, however. The electrodes for his arc light are graphite brushes from an electric streetcar, while the battery is an incredibly sketchy-looking collection of 98 18650 lithium-ion cells. A scary rat’s nest of coiled cable acts as a ballast to mitigate the effects of shorting when the arc is struck. The reflector is an old satellite TV dish covered in foil tape with the electrodes sitting in a makeshift holder where the feedhorn used to be. It’s bright, it’s noisy, it’s dangerous, and it smokes like a fiend, but we love it.

Mounting it to the front of the bike was just for fun, of course, and it works despite the janky nature of the construction. The neighbors into whose apartments the light was projected could not be reached for comment, but we assume they were as amused as we were.

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Can A Motorized Bicycle Run On Trees?

October 17, 2018 by 59 Comments

Some of the earliest automobiles weren’t powered by refined petrochemicals, but instead wood gas. This wood gas is produced by burning wood or charcoal, capturing the fumes given off, and burning those fumes again. During World War II, nearly every European country was under gasoline rations, and tens of thousands of automobiles would be converted to run on wood gas before the war’s end.

In the century or so since the first car rolled on wood gas, and after hundreds of books and studies were published on the manufacturing and development of wood gas generators and conversion of internal combustion engines, there’s one question: can someone convert a moped to run on wood gas? [NightHawkinLight] finally answered that question.

The basic setup for this experiment is a tiny, tiny internal combustion engine attached to a bicycle. Add a gas tank, and you have a moped, no problem. But this is meant to run on firewood, and for that you need a wood gas generator. This means [NightHawkinLight] will need to burn wood without a whole lot of oxygen, similar to how you make charcoal. There is, apparently, the perfect device to do this, and it’ll fit on the back of a bike. It’s a bee smoker, that thing bee keepers use to calm down a hive of honeybees.

The bee smoker generates the wood gas, which is filtered and cooled in a gallon paint bucket filled with cedar chips. The output from this filter is fed right into where the air filter for the internal combustion engine should be, with an added valve to put more air into the carburetor.

So, with that setup, does the weird bike motorcycle wood gas thing turn over? Yes. The engine idled for a few seconds without producing any useful power. That’s alright, though, because this is just a proof of concept and work in progress. Getting this thing to run and be a useful mode of transportation will require a much larger wood gas generator, but right now [NightHawkinLight] knows his engine can run on wood gas.

Cheating The Perfect Wheelie With Sensors And Servos

September 24, 2018 by 8 Comments

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

August 29, 2018 by 45 Comments

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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More Suspension Than Necessary

August 6, 2018 by 20 Comments

The triangular frame of a traditional mountain bike needs to be the most rigid structure, and a triangle can be a very sturdy shape. So [Colin Furze] throws a spanner in the works, or, in this case, a bunch of springs. The video is below the break, but please try to imagine you are at a party, eyeballing some delicious salsa, yet instead of a tortilla chip, someone hands you a slab of gelatin dessert. The bike is kind of like that.

Anyone who has purchased springs knows there are a lot of options and terminology, such as Newton meters of force, extension, compression, and buckling. There is a learning curve to springs so a simple statement, for example “I want to make a bicycle of springs,” doesn’t have any easy answers. It is a lot like saying, “I want to make a microprocessor out of transistors“. This project starts with springs roughly the diameter of the old bike tubes, and it is a colossal failure. Try using cooked spaghetti noodles to make a bridge.

The first set of custom springs are not up to the task, but the third round produces something rideable. The result seems to be a ridiculous way to exercise your abs and is approximately a training unicycle mated with a boat anchor.

What makes this a hack? The video is as entertaining as anything [Colin] has made, but that does not make it a hack by itself. The hack is that someone asked a ridiculous question, possibly within reach of alcohol, and the answer came by building the stupid thing. A spring-bicycle could have been simulated six ways from Sunday on an old Android phone, but the adventure extracted was worth the cost of doing it in real life.

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The Apocalypse Bicycle

July 28, 2018 by 66 Comments

It seems to be a perennial among humans, the tendency among some to expect the End Times. Whether it was mediaeval Europeans who prepared for a Biblical Armageddon at the first sight of an astronomical phenomenon, 19th-century religious sects busy expecting a Noah’s flood, cold-war survivalists with bunkers under the lawn, or modern-day preppers buying survival gear, we have a weakness for thinking that Time’s Up even when history shows us repeatedly that it isn’t. Popular culture has even told us that the post-apocalyptic world will be kinda cool, with Mad Max-style rusty-looking jacked-up muscle cars and Tina Turner belting out ballads, but the truth is likely to be a lot less attractive. Getting away from danger at faster than walking pace as a starving refugee would likely be a life-or-death struggle without the industrial supply chain that keeps our 21st-century luxury cars on the road, so something more practical would be called for.

[Don Scott] has written a paper describing an extremely straightforward solution to the problem of post-apocalyptic transport, which he calls the Apocalypse Bicycle. As you might expect it’s a two-wheeler, though it’s not the kind of machine on which you’d lead a break-away from the Tour de France peloton. Instead this is a bicycle pared down to its minimum,, without advanced materials and with everything chosen for durability and reliability. Bearings would have grease nipples, for instance, the chain would be completely enclosed for better retention of lubrication, and the wheels would be designed to have strips of salvaged tyre attached to them. Interestingly, the machine would also be designed not to attract attention, with muted matte colours, and no chrome. It occurs to us that many of the durability features of this machine are also those that appear on the rental bicycles owned by bike sharing companies that have been spread liberally on the streets of many cities.

You might wonder what use the idea might have, and why a prepper might consider one alongside their tins of survival rations. But it’s also worth considering that these machines have a real application in the here-and-now, rather than just an imagined one in an apocalyptic future. Many Hackaday readers are fortunate enough to live in countries unaffected by wars or natural disasters, but there are plenty of places today where an aid agency dropping in a load of these machines could save lives.

Apocalyptic cycling has featured little here. But we have brought you at least one bike made from wood.