DIY


22
Jun 2012
by larry

Why I Invented an Electric Bike for Carrying Adult Passengers

Thea and JJ model the passenger bike prototype.

“On June 4, 1896 in a tiny workshop behind his home on 58 Bagley Street, [Henry] Ford put the finishing touches on his pure ethanol-powered motor car. After more than two years of experimentation, Ford, at the age of 32, had completed his first experimental automobile…The two cylinder engine could produce 4 horsepower…achieving a top speed of 20 mph (32 km/h). Ford would later go on to found the Ford Motor Company and become one of the world’s richest men.”
Wikipedia

I’m gradually reducing my car dependance. I enjoy traveling to meetings, hauling groceries, and taking my kids to their dental appointments all on my bike. But one of the few remaining compelling reasons for using my car is to carry adult passengers. For a variety of reasons my adult friends and family do not feel comfortable hopping onto my longtail cargo bike. Can bicycles ever fulfill the role of carrying adult passengers? I believe they can, and (like Henry Ford) I’ve built an experimental vehicle to test my conviction.

Here are the design goals I began with: build a bike that can safely and comfortably carry both a 200-pound driver and a 200-pound passenger at an average speed of Continue reading →


22
Apr 2012
by don

Shawn’s Electric Yuba Mundo

 

The author giving his touring bike a break

Today’s article comes from a guest contributor, Shawn McCarty of Venice, Florida. Shawn is an avid cyclist who has completed bike tours through various parts of the United States and Europe. His blog (aworldspinning.com) has some nice photos of his European adventure. And his custom electric cargo bike is amazing!

If you have biking facts, photos, or a story you think our readers would enjoy, let us know. We’re interested in presenting a variety of topics and points of view as we build our biking community.

Continue reading →


9
Dec 2011
by larry

Currently in the Clarkberg Bike Stable


Here’s a little photo essay about my family’s bicycles. I’m proud to say that we use our bikes a lot. Each bike is tailored to its user: I drive a cargo bike capable of carrying passengers and cargo long distances; my wife drives a slower and lighter but more stylish bike; my 11-year-old daughter Thea and her friend JJ drive bikes tailored to their 2-mile drive to school. (My son Jasper, aged 15, resists having a bike. He pretty much walks wherever he needs to go.) Ithaca is hilly, so it’s important for a utility bike to have an electric motor. I’ve spent a lot of time over the last couple of years  experimenting with electric bike motors and other accessories. Maybe you can benefit from my discoveries.

Continue reading →

4
Oct 2011
by larry

Aqua-Xtracycle, the Amphibious Bicycle

boating mode: the boat carries the bike

boating mode: the boat carries the bike

biking mode: the bike carries the boat

biking mode: the bike carries the boat

The Aqua-Xtracycle is a do-it-yourself amphibious electric cargo bike. This video shows how it works, and the photo gallery below shows a bit of our development process. In a future post I’ll describe how you can make your own Aqua-Xtracycle.

Continue reading →

19
Aug 2011
by larry

My DIY SLA Trip Batteries


Test drive to Sheldrake Point

Test drive to Sheldrake Point

Caution: shop talk blog post intended for do-it-yourselfers. For my recent 240-mile journey I created what I call my “trip batteries”—batteries that I can attach to my bike to augment my regular batteries, but that I don’t intend to carry around on a daily basis. As such, the main design criteria for these batteries is that they be inexpensive. I don’t want to pay the big bucks for a battery that I only use once in a while. The obvious choice is SLA (sealed lead acid) batteries. These are the same kind of batteries used in cars, and the technology is almost 100 years old. E-bikers out there may poo-poo this choice of battery. After all, compared to my lithium batteries, my SLA batteries are heavy (20lbs vs. the lithium’s 15lbs), not quite as powerful (600wh vs. the lithium’s 720wh), don’t last as long (300 charge cycles vs. the lithium’s 1,500) and they are dumb (that is, they don’t have a battery management circuit board in them to prevent human error from damaging them, although most controllers provide the necessary protections). But they are cheap. I can put together a 10ah 36v battery for about $120 versus a 10ah 36v battery for $600.

Continue reading →

28
Jul 2011
by larry

Long Distance Trip on My Ebike Workhorse

A couple of weeks ago I set out on a 240-mile journey from my home in Ithaca NY to the New York Yearly Meeting (a Quaker gathering) in Silver Bay. Silver Bay is a resort on Lake George in the scenic Adirondacks. My vehicle of choice: a Surly Big Dummy cargo bike equipped with a Stokemonkey electric motor. I had made this journey last year covering the distance in three days. This year I planned to tackle the distance in two days, going 120 miles each day.

Last year my strategy was to charge my batteries en route using three solar panels supported over the rear of my bike. The solar panels were helpful, but couldn’t generate as much electricity as I needed. This year I upgraded my bike to use two 36-volt LiFePo4 batteries in series (for 720 watt-hours), and for this trip I carried an additional pair of 36-volt SLA batteries (for an additional 600 watt-hours). All of these batteries together weigh about 70 pounds.

I purposefully limited the amount of power my bike could draw from the batteries. My 72-volt system can easily push my bike over 20 mph, but at that speed my distance would be limited to about 60 miles. However, if I kept my speed between 10 and 15 mph I could get a full 120 miles out of my batteries, though I would have to be in the saddle 12 hours.

Continue reading →

1
Oct 2010
by larry

Sweat Is Your Friend

This summer was one of the hottest summers on record. Several people have asked me how I managed to survive. My response: I didn’t notice. I didn’t notice it was unusually hot in spite of spending much of my time outdoors training for a marathon and doing my errands by bike. I didn’t notice precisely because, counter-intuitively, these activities caused me to sweat and my sweat kept me cool. How could this be?

For some reason our culture has an aversion to sweat. Our media keeps up a constant barrage of messages about how we must avoid sweating and that if we do somehow err by sweating we must hide it at all costs. Of course there is a place for personal hygiene and we must take care not to impose our old smelly sweat on our fellow citizens. But we sweat for a reason–to keep ourselves cool–and furthermore we are very good at sweating.

A recent Scientific American article described how one of the most basic ways our human ancestors gained an advantage over other predators is by our ability to sweat. No other animal sweats as well as we do. This ability enabled our ancestors to track large game until it fell over from heat exhaustion, a technique known as persistence hunting. Many other animals can outrun us for short distances. But we are the masters of long distance running on this planet. A human can run a marathon faster than a horse, because the horse will keel over from heat exhaustion before it gets to the finish line. And so how do we make use of this great ability of ours in modern times? Do we augment our ability to keep cool in some way as we have done with so many of our other abilities? No, instead we vilify anyone who sweats in public. It is outrageous to me that we subvert this great advantage we have for dealing with hot weather, then complain about the weather, then build big machines to make ourselves cooler, and finally watch complacently as these machines contribute to the very climate warming we were complaining about.

I propose that instead of looking at sweat as the enemy we learn to harness it for its intended purpose: to cool us down. It is much more energy efficient to cool ourselves individually (perhaps with motion or fans) than to use big energy-intensive machines to cool down entire rooms and buildings. And it is the height of hypocrisy and inefficiency that our cars are designed to be basically greenhouses on wheels. As a result they must carry massive air conditioning equipment to keep their occupants cool. Instead, cars could make use of our natural abilities to cool ourselves by sweating and combine that with the built-in breeze of their forward motion.

Air conditioning will be one of the first superfluous accessories jettisoned by our lightweight/narrow/slow cars of the future. What will replace it? Think about the vents cars have now and how they could be improved. It seems that no one in our bone-headed auto industry has taken the time to reconsider the simple air vent. What are some ways it can better put a breeze where it’s needed? For that matter, where is the breeze needed? Sweating effectively requires having airflow over one’s back. Current cars place your back squarely in a cushy seat with no possibility of air flow. What if for starters cars had mesh seats? What if we had the vents blow directly from the seat onto our backs? Or better yet, what if we had ventilated clothing that clipped directly into the car’s cooling system? And we won’t need any kind of sophisticated automatic temperature control. Just provide a steady air flow and your body will sweat or not as necessary to keep itself comfortable.

You are probably wondering “What if I don’t have one of those lightweight/narrow/slow cars of the future? How can I keep cool by sweating while traveling?” If such is the case I propose that you make do with an electric cargo bike, which is the next best thing to a lightweight/narrow/slow car of the future. Here are my tips for sweating more effectively in hot weather:

  • Use an electric bike. Moving on an electric bike is especially nice since it can provide a breeze without so much exertion. And if you are on foot, my experience is that someone can actually stay cooler by running slowly and efficiently rather than walking. The faster airflow from running combined with sweating kept me cooler than the slower airflow (but less exertion) of walking. However, running efficiently takes practice. It probably also helps to be thin.
  • Don’t wear a backpack while biking. Backpacks block air flow. Get a cargo bike so you can carry your stuff off your body.
  • Wear sunscreen.
  • Go shirtless. Don’t be a prude dude. Let the sweat out. But carry a jacket for when you stop.
  • Carry twice as much water as you think you’ll need. You’ll need it.
  • Only stay in the sun if you are moving. The airflow will keep you from overheating.
  • Cool down in front of a fan after biking. You will notice a surge in body temperature after you stop biking, with a corresponding surge in sweat output. Don’t waste that sweat! Cool down with whatever breeze and fan and shade you can find. Only after the sweat has completely evaporated should you take a shower if circumstances require.

So this summer by following these simple tips I actually looked forward to biking and running as an opportunity to go outside and cool down. I did not let the weather reports dictate whether or not I could go outside. Don’t believe me? Try befriending your sweat!


18
Jul 2010
by larry

My Solar Bicycle

I am anticipating peoples’ reactions:

“Why do you have solar panels on your bicycle?”

“What do you do when it rains?”

“Can the solar panel drive the electric motor directly?”

“Did you make it yourself?”

“What the…”

Allow me to explain. My vehicle of choice is a “stoked Xtracycle”. (For those of you not “in the know”, an Xtracycle is a type of cargo bike that has an extra long frame. And “stoked” means that my bike has a Stokemonkey electric motor that helps me out on the hills.) In general this summer I’ve been biking 10 to 20 miles a day and then recharging my battery overnight by simply plugging it into an outlet. However, next week I’m going on a 3-day 240-mile camping trip through the Adirondacks where I might not have access to an outlet. The solar panels will help extend the range of my bicycle. So to answer your questions:

“Why do you have solar panels on your bicycle?”

I use them to extend the range of my electric cargo bike for long trips (plus they were fun to make). I will carry two batteries on my trip, each giving my bike a range of 20 to 40 miles. On a sunny day the solar panels can recharge one of the batteries while I am riding, adding an additional 20 to 40 miles for a total range of 60 to 120 miles a day. I anticipate some hills and I’ll be carrying a load, so a 60-mile range is probably more accurate. I may need to pedal the last few miles on some days.

“What do you do when it’s cloudy or it rains?”

I plan to stay in a hotel some of the time and recharge my batteries there.

“Can the solar panel drive the electric motor directly?”

Not really. The solar panels don’t produce enough electricity instantaneously. For example the solar panels only produce about 40 watts of power at a given moment, whereas my bicycle needs about 400 watts of power to go up a hill. The main purpose of the solar panels is to charge the battery over time.  Since charging happens slowly, 40 watts is enough to charge the battery. It takes roughly 10 hours of charging to store one to two hours’ worth of electrified riding time in the battery. And one to two hours of riding translates into 15 to 30 miles.

“Did you make it yourself?”

I already had the stoked Xtracycle, which is described on my About This Bike page. As you can read there, an electric cargo bike can be had for $1000 to $3500. And I had already constructed the canopy frame for a previous project, the Bike Wagon Canopy ($150). I found the canopy was somewhat wobbly with the weight of the solar panels so I had to strengthen it with guy wires. It remained for me to add the solar panels and the electronics. I used maritime-grade solar panels that were designed to keep sailboat starter batteries charged up, so they are extra-sturdy and consequently somewhat expensive. I’ve since seen panels with almost twice the power at 3/4 the price. Cost of panels: $900 to $1200. I am using three 12-volt panels in series to produce the 36 volts required by my battery. I spent a lot of time researching what sorts of electronics I would need between the panels and the battery, and finally concluded that I can just plug the panels into the battery directly. (I plan to write more about this in a later post.)

Total cost for a solar bicycle: $2050 to $4850. Not bad for a vehicle that can get you both out of the car and off the grid.


7
Jun 2010
by larry

How to Make the Bike Wagon Canopy for Xtracycles

Bike Wagon canopy

In a previous post I described a canopy that Thea and I made for our Xtracycle to protect her from wind and rain. It looks sort of like a covered wagon on the back of our bike. It was easy to build without special tools or parts, did not require modifying our bike and cost us less than $150 for parts. It weighs about 2 lbs. and we can set it up in less than five minutes. Here’s how to make it.

Materials You Will Need

Tools You Will Need

Ordering Suggestions

order from Quest Outfitters:

#1024 1.1 OZ SILNYLON 1STS , (Tan)…3 at $9.99 =  $29.97
#4060 TENT POLE W/ INS .625 18 inch Black…4 at $4.95 = $19.80
#4061 TENT POLE W/O INS .625 18 inch Black…1 at $3.95 = $3.95
#4018 TENT POLE W/INS. .340 18 inch Black…12 at $2.60 = $31.20
#4019 TENT POLE W/O INS .340 18 inch Black…2 at $2.20 = $4.40
#4055 TENT POLE ARCH-145 DEGREE .340 BLACK…4 at $2.95 = $11.80
#2000 WEBBING- NYLON MED WT 1/2 inch Black..25 at $0.49 = $12.25
#3026 SIDE RELEASE BUCKLES – 1/2 inch…4 at $0.39 = $1.56
#4200 tubing cutter…$7.95
#3235 grommet tool (5/16″)…$10.99
#3231 (10) 5/16 grommets…10 at $0.18 = $1.80

purchase at a hardware store:

(1) 7/8″ x 48″ dowel…$3
(4) 3/4″ long wood screws…$1
(4) #6 x 3/4″ machine screws and nuts…$1
25 feet of light tie-down cord such as cotton clothes line…$5

TOTAL: $145.67

How to Make the Canopy Cover

The rectangular canopy cover fits over the canopy frame and is secured at the bottom with tie-down straps. The front and back of the cover can be cinched up with a drawstring like a covered wagon. If you like, the cover’s size can be adjusted, along with the frame’s pole lengths, for different sizes of passenger. The size I give here is appropriate for a large child or small adult.

How to Make the Canopy Frame

How to Assemble the Canopy

CAUTION: do not leave your canopy frame uncovered. Without the cover it is only held together by friction. If jostled it could come loose and snap back with surprising force (and for example break a garage window as I learned from experience). DO NOT ride your bike with an uncovered frame (again as I learned from experience you don’t want to be picking up all 20 tent poles in traffic). If you want to use the frame for some purpose other than the Bike Wagon canopy, consider putting a shock cord within it or using external guy wires as I do for using it to support my solar panels.

Final step: do me the courtesy of sending me a photo of your finished canopy!

How to Cut an Aluminum Tent Pole with a Pipe Cutter

How to Add a Grommet to the Canopy Cover

How to Make a Canopy Sack

If you have enough cloth left over you can use it to make a canopy sack.


3
Jun 2010
by larry

Tension, Integrity, and the Design of Lightweight Vehicles

The ElectraFlyer ultralight. Note the guy wires. Its electric motor weighs twice as much as my Stokemonkey motor (26 vs. 13 pounds) but it has 18 times the horsepower. The battery weighs 6.5 times my 36v 10ah Prismatic LiFePo4 (78 pounds vs. 12 pounds) but produces about 10 times the power. An Xtracycle with this monster motor and battery would add 104 pounds to the bike but would increase the range to 250 miles. Add that wing, throw in a propeller and my Xtracycle could fly!

Thomas Morse Scout showing guy wires. Incidentally this plane was manufactured in Ithaca the small town where I live.

I’ve been trying to wrap my head around guy wires. No that doesn’t mean wires made by guys. It means a tensioned cable used to brace parts of a structure or vehicle. For example have you ever noticed the cables forming Xs between an old biplanes’ wings? Those cables prevented the two wings from moving relative to each other. They also made it possible for a biplane to be lightweight. As biplanes’ motors became more powerful weight has not been so much of  a factor and you don’t see as many or any cables on a modern biplane. However you do see cables on ultralight aircraft as shown. More and more you see cables used in architecture. I argue that we need to use more cables—and parts under tension in general—in the design of our cars.

Guy wires to stabilize my solar canopy.

I recently needed to add guy wires to my Bike Wagon canopy design because when I put my solar panels on top of the canopy, the added weight made the canopy wobbly. A few cable Xs solved the problem. It got me thinking about how the design of ultralight airplanes and bicycles and lightweight vehicles in general requires using tensegrity. Say what? “Tensegrity” is a word that American architect and inventor Buckminster Fuller made up by combining the word “tension” with the word “integrity” to describe a new building technique. The basic idea is that you can make way cool lightweight structures by combining something with structural integrity (such as a hunting bow) with something that is under tension (such as the bow string).Tensegrity structures can have the unnerving property that the beams of the structure don’t actually touch each other (see the Tensegritoy below). Our bodies themselves use tensegrity: our bones provide the structural integrity and our ligaments and muscles provide the tension.

A wonderful way to get hands-on experience with tensegrity is to order a Tensegritoy kit.

The bicycle wheel is another good example of tensegrity. Back in the day wheels were constructed using wooden spokes. The spokes needed to be thick and heavy. The bicycle wheel, in contrast, uses tensegrity. The rim provides the structural integrity and the spokes provide the tension. This design creates a very strong lightweight wheel. A car wheel (excepting the occasional MG) does not use tensegrity; it is solid metal. A car’s large powerful internal combustion engine overwhelms any need for weight savings. Incidentally there are commercially successful bike frames that use tensegrity.

The Millenium Dome in London is constructed out of steel towers and tensioned fabric.

Tensegrity is a revelation in architecture. The first large buildings relied on gravity and the compression strength of stone to hold themselves up. Then with the invention of the steel I-beam, buildings could use the structural integrity of the I-beams to hold themselves up. More and more architects are experimenting with tension components such as steel cables and fabric. Some of these structures are what the layman would call a tent. However, we’re talking tents that are very large permanent structures such as the 1,200 ft. wide (365 m) Millennium Dome. Two related ideas are tensile structures (elements carrying only tension and no compression or bending) and tensairity structures (pneumatic structures that use inflated airbeams and attached stiffeners or cables).

Buckminster Fuller's Dymaxion Car. It was about 6 feet tall, seated the driver and 10 passengers, weighed less than 1000 lbs., went 120 miles/hr on a 90 horsepower engine, and got between 30-50 miles to the gallon of gas!

I believe road vehicles need to undergo a similar transition—from compression to tension components in their construction—so that they can become light enough to be powered by humans and by sunlight. Contemporary cars have structural integrity mainly by virtue of the strength of steel. I envision lightweight slow small vehicles that use aluminum poles, cables, and fabric to give them shape. Is this possible? It can’t hurt to dream big. In 1930 Buckminster Fuller’s own car invention, the Dymaxion Car, weighed less than 1000 pounds and could carry 10 passengers.