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 →
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!
The day began overcast. Not a good start for the Solar Xpedition. But by midday Mr. Sun broke through and the watt hours came rolling in. I ran with my solar panel connected to the working battery (rather than the spare). It was exciting to see the power drop as I went up a hill and then gradually be restored by the panel.
My power use went very well the first day. I didn’t even need to get out the spare battery. It’s hard to know how much of the 500 watt hours I used the first day was supplied by the panel since I don’t yet have a way to measure watt-hours output. But I estimate that the battery had 360 to start with, the solar panel added 70 and charging at a restaurant while eating dinner added 70.
Many things didn’t go well, in particular 7 flat tires and swarms of mosquitos at my campsite.
Stay tuned for day 2.
charging up while I take a nap.
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?”
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.
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
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
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.
As I’ve mentioned in a previous post, there seems to be a need for a practical bike canopy. My first efforts have been to develop a passenger-only canopy for Xtracycles. [Instructions for the finished canopy are now online in a later post.] My design goals:
- protects an adult or child passenger from wind and rain and temperatures above freezing while giving them some visibility
- can be set up in less than a minute
- fits any Xtracycle
- costs less than $100 for parts
- is easy to build without special tools or parts
- is easy to enter and exit
- adjusts for differently-sized passengers from baby to adult
- adjusts for different weather conditions
- provides a platform for flexible solar panels
- should weigh less than 10 lbs.
- does not require modifying the bike
- not necessarily aerodynamic
- retains the Xtracycle Freeloader cargo capacity
- presents a snappy appearance
Last February Thea and I constructed and tested a rough prototype. I am pleased to announce that after trying out many design variations and solving several engineering challenges, we’ve created a very pleasing and useful design as shown. Later this spring I intend to post detailed instructions so that anyone can create their own canopy. A historian writing about conestoga wagons wrote the following, which I hope also applies to my Bike Wagon canopy:
All chronicles agree that a fully equipped Conestoga wagon in the days when those wagons were in their prime was a truly pleasing sight, giving one that sense of satisfaction which ever comes from the regard of any object, especially a piece of mechanism, which is perfectly fitted for the object it is designed to attain.
I’m currently testing flexible solar panels mounted on top of the canopy. The solar panels should be able to double the range of my bike. And it may be possible that I can just park my bike outside and never have to connect it to an outlet again! A solar-powered stoked Xtracycle may very well be one of the most practical solar vehicles available, if you measure practical in terms of being relatively inexpensive, having spare parts readily available, and being street legal. It’s not speedy or futuristic-looking, but it’s here now.
My Next Canopy Project: The Micro Car
I plan a second canopy development effort in the fall. This second canopy design will be for both driver and rider. I intend for it to be mainly for winter use as a way to replace a car during that most difficult of biking seasons. I hope that people will think of it as a very small but practical car: a micro car if you will. As computer sizes fell from mainframe to mini to micro in the eighties, so I hope that car sizes will fall from the grossly gross SUV to full-size to mid-size to compact to mini to the delightful micro car. Here are my design criteria:
- protects the driver from rain while giving full ventilation
- protects the driver’s hands from wind and temperatures 10 degrees and above
- gives the driver full visibility
- insulated (perhaps with Aerogel batting) to keep an adult or child passenger comfortable at temperatures 10 degrees and above while giving them some visibility
- only needs to be set up and removed at the beginning and end of the cold season
- fits any Xtracycle
- costs less than $1000 for parts
- may require special tools (such as a welder) or special parts
- is easy to enter and exit
- adjusts for differently-sized passengers from baby to adult
- can weigh up to 30 lbs.
- may require modifying the bike
- may have electrical features such as a sound system and lighting
- may be somewhat aerodynamic
- retains the Xtracycle Freeloader cargo capacity
- presents an appearance that inspires confidence in the project
I’ve attached some sketches and photos of my Bike Wagon and Micro Car prototypes below, from past to present.
Winter biking can be excruciatingly uncomfortable in Ithaca. (It can also be dangerous—see Making Winter Biking Safer.) This winter I developed two bike accessories to combat the cold: electric bike gloves and a bike canopy (which is still in development).
If I bike an errand longer than a few miles and the temperature is in the teens, my fingers and toes tend to go numb. Numb is okay until I stop and warm up; I then become doubled over in pain as my extremities thaw. I’ve tried all kinds of gloves to no avail. And I discovered that if I wore several gloves at a time my fingers still got cold because their circulation was lessened. Finally I hit upon the idea of using electric socks and glove liners. Personal electric power is just one of the many design opportunities presented by electric bikes that have yet to be explored (while the transportation industry wastes their time with stupid technologies like hybrid cars and hydrogen power). The electric socks and glove liners I bought (from Brookstone) were powered by a total of 12 AA non-rechargeable batteries that you had to strap to your limbs (three batteries for each limb). I realized that with a little inventiveness I could power them all with the bike battery instead.
Using the bike battery required figuring out how to get the electricity from the battery to my extremities. First I lined my coat and some snow pants with wiring using safety pins, and then I added Anderson connectors and a central connection block. Anderson connectors are a wonderful kind of connector for inventing things. You can just crimp the wires on and then snap together as many connectors as you need.
I also needed some way to step down the voltage from the battery’s 36 volts to the electric clothing’s 4.5 volts. I found that ebikes.ca sells such a converter especially made for electric bikes. (These are the same folks that made my front and rear LED flashers.) A word of caution: I learned from experience that if you plug the converter in backwards sparks will shoot out of it. However, it still works! I marked all my 6-volt connections with purple tape.
Finally I wanted an easy way to connect my clothing to the battery as I got on and off the bike. I expected that some sort of slick magnetic breakaway connectors like the ones Macintosh computers have would be available. There was nothing. Two possibilities—the Belkin BreakFree or Replay breakaway headphone adapter advertised in 2007 and 2008—are nowhere to be found. I suspect that Apple has a patent on magnetic breakaway connectors that is preventing others from selling them. So I ended up just using my Anderson connectors.
The results: after some trial and error it worked. One problem was that the wires I used were old and they broke a few times. (Once my left foot suddenly grew uncomfortably warm while my hands suddenly became cold.) Also I was nervous that I might damage my expensive LiPoFe4 battery. It is true that LiPo batteries can be damaged by either too much charging voltage or dropping too low in voltage. However, most of them also have very sophisticated battery management systems built in to prevent this. Finally it was too inconvenient to attach and detach the wires all the time so I started using an old NiCd battery instead.
Next year maybe I’ll explore some alternatives such as handlebar muffs or windscreens or heated handlebars grips. I wonder if it’s possible to find flat wiring that you can sew into a garment. And here’s another design opportunity: one problem with biking in winter is that you are too hot on the uphills and too cold on the downhills. With electric garments you can control the heat. One way to do it is that you could have a clutch to spin the motor on downhills and switch on the garment connection. Or you could use the computer to sense your speed and switch on the garment connection when you are going over say 15mph. I’ll keep you posted.
After my bad fall last December I’ve been thinking a lot about how to make winter riding safer. The first step was to install studded snow tires for both wheels. My fall was caused by only having a snow tire on the back wheel; my front wheel slid out from under me when I was going downhill at 20mph with my daughter on the back of the bike (she was unhurt). There is no good reason not to wear snow tires during winter. My tires of choice are the Schwalbe Marathon Winters, which are designed for icy pavement rather than deep snow.
Another safety factor is simply learning to recognize danger. Some conditions are more dangerous than others. Just before my fall last December I had ridden five miles without incident. It was only when I turned onto a new road that things became dangerous. The new road was recently plowed and the shoulder had a thin layer of innocent-looking slush. Unbeknownst to me the slush hid a layer of ice that was my undoing. I’ve since learned to recognize this “killer slush” and avoid it.
Another danger to watch out for is of course the legendary “black ice” (see photo above) which is caused by melting snow forming puddles which then turn into patches of ice in unexpected places. Now when I ride in the winter I periodically set my foot down to test the slipperyness of the road. If it’s too slippery I either walk my bike or resort to “outrigger mode” (described in the last paragraph).
After my fall I imagined all sorts of technological fixes that would enable bikes to handle snow and ice better (see some of my sketches below, and see http://www.ktrakcycle.com/ for a seemingly successful commercial product). Could bikes have anti-lock brakes? Apparently motorcycles do, and electric bikes already have the electricity and the computing power that is required. Could bikes have roll bars? How about caterpillar treads?
I also wondered whether a trike would be less likely to flop over when it encountered ice. I made a lot of sketches of trikes, and contemplated Xtracycle to trike conversions. I imagined outrigger wheels that could perhaps fit into the Xtracycle H-rack mounts and prevent a bike from falling over, kind of like giant training wheels for adults. However, someone I know who rides a trike says that in the same situation as my fall a trike would probably flip over rather than lay onto its side. I scuttled my plans for constructing outriggers until I was riding with my son Jasper last week in packed-snow conditions. The going was so difficult that he simply stuck out his legs, planted his feet on the road and let the motor move him along. It struck me that here are the outriggers I was looking for—our legs! They were right here all along at the end of our torsos. So for riding on packed snow I recommend lowering your seat, taking off your toe clips, letting some air out of your tires, taking your feet off the pedals, and taking off. This style of riding wouldn’t have been possible without the advent of electric motors for bikes. Now how about roller-shoes for pavement or ski-shoes for deep snow?
I’ve been doing a little research on bicycle canopies. There are surprisingly few examples out there. Here are a few that come up on the top of a web search.
(Update: check out my own canopy design and instructions for making it.)
Top of the list is the Bicycle Canopy Company. The name sounds promising but the product does not look much better than my prototype. Owner Jill Nerkowski writes “I joined my landscaping and gardening experience with bicycle mechanics and came up with my idea for a traveling greenhouse…This bicycle canopy can be constructed in your home, with ordinary household tools and easy to purchase materials.” You have to give her credit for her massive amounts of hutzpah. She looks like a lovable kook but hey, there but for the grace of God go I .
Farther down the list is someone who back in 2005 announced his search for any sort of bicycle canopy. He concluded that most of the work being done so far to create a weatherproof bike has been the creation of velomobiles: short bullet-shaped bicycles with a hard enclosure. Velomobiles don’t seem to be good car-replacement vehicles. The tend to emphasize speed, they are expensive and they weigh a lot. I can’t imagine them carrying cargo or a passenger.
I came across this guy Joe Kochanowski who has made over 50 recumbent (a.k.a bent) bicycles over the last twenty years, some of them enclosed like a velomobile. He writes “I am not married so I can do things like overhaul a car engine in my living room without anyone complaining.” I admit to a bit of envy. Go Joe.
As usual the Europeans are way ahead of us in bicycle technology. The French have brought to market what appears to be the only commercially successful bike canopy I’ve seen.
Here’s a cute review by a young citizen:
I’m concluding that the bike canopy field is wide open. My design has many elements that I haven’t seen elsewhere: integration with the open-source Xtracycle standard; cold-weather insulation; use on an electric cargo bike; and the highly flexible conestoga design. What I’ve seen is canopies designed for either speed or light rain protection. I haven’t seen any designs that are a serious approach to car-replacement.
For some reason I haven’t seen any Xtracycle canopies. You’d think this would be a popular idea in rainy Portland Oregon which is a nexus of the bike movement. I think the Xtracycle is uniquely suitable for a canopy because both the driver and passenger are on the same bike. This allows one large canopy. The main protection needs to be for the passenger and cargo (perhaps using aerogel insulation which is extremely efficient, thin, and lightweight and may someday be available transparent). The driver, who will be hot from exertion, just needs to be protected from rain and wind. (In my experience I get quite hot biking even in the coldest weather. Maybe a very well insulated canopy could allow the driver’s excess body to warm the passenger.) I think a design that emphasizes covering a passenger will also be easier for the general public to accept. People have already seen plenty of bike trailers with such coverings. With an Xtracycle, it’s a small step to extend the passenger covering to the driver.
Another design opportunity is that the Xtracycle allows you to connect a canopy much farther forward and back than other bikes. The forward connection can even be to the sides of the pedals without interfering with the pedals. If you’ve ever carried lumber on an Xtracycle equipped with the Long Loader accessory you know what I mean.
Another design opportunity: the canopy provides a place to put your flexible thin-film solar panels.
Another design opportunity: the power of an electric bike makes it possible to have a heavier perhaps wooden “wagon” that you can just chuck stuff into or even lock it up. I can imagine a pick-up truck like bicycle. Maybe the bottom of the wagon should be curved like a Conestoga wagon so the cargo doesn’t fly out. Then you just attach a canopy when necessary.
I commend the brave souls noted in this post for the work they’ve done to advance the cause of making bicycles practical for year-round use. I am perplexed that this cause has been completely abandoned by industry, government, and yes, even bicycle manufacturers.
I conceived of and constructed this canopy in less than an hour. The design was inspired by conestoga wagons. The canopy consists of two hoops made out of 10-foot-long metal tubing that I duct-taped to the corners of my Xtracycle cargo van extension. I then duct-taped two cross-braces to the hoops and covered the whole thing with Tyvek house wrap.
Thea and I took it for a test drive this afternoon. It was surprisingly successful for a working prototype. The biggest flaw was that the Tyvek was incredibly noisy. We figured we should use nylon fabric such as the fabric a tent fly uses instead. And it would be great if the passenger could zip up the enclosure front and back. Also it would be nice if the hoops spread out more to the front and back like a conestoga wagon, but with some adjustment possible so as not to hit the driver. Would it be possible to make a third hoop that partially covered the driver?
I can imagine finding the time to sew a canopy like this. I would also want to replace the metal hoops with fiberglass tent poles and replace the duct tape with cross-ways clamps.