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.
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.
I’m trying out a new battery box for our electric Yuba Mundo.
I used the weather-resistant compact file tote from OfficeMax. Inside I’ve placed our 36V 15Ah battery from Cycle9.com, which has first been padded in Granite Gear armored pocket. The padded battery fits snugly at the bottom of the box. Perfect!
The box has small handles, and I used this area to cut a small hole with a utility knife for the battery wire to come through. This placement means water would have to be going up to get into the box, so I’m expecting no rain and very little road spray could make in it there. ( Adding drain holes to the bottom could also be a good idea, just in case. )
The electric Yuba Mundo works well asa kid & cargo winter bike. Recently I’ve been trying out Bar Mitts which so far seem to very effective at keeping my hands warmer while allowing me to wear thinner gloves inside of them. Compared to the bakfiets, the child needs to be dressed notably warmer. Since this photo was taken, we’ve also gotten some child ski goggles for her as well. In sum, we’re able to make cross-town trips comfortable at 15F (-9.4C) which is about as cold as it gets here in Richmond, Indiana.
The bakfiets makes it easier to keep the child warm with the greenhouse-like canopy, and the fully enclosed chain guard is definitely a plus for the bakfiets– On the eMundo the drive train got clogged with frozen slush in just about 15 minutes on a cold day– it was easy to clean out a little later with a stick, but no fun– plus the eMundo chain will need to be cleaned more after getting wet.
However, what the eMundo has going for it is a motor which allows me to get places faster and spend less time outside on very cold days. For that reason I currently prefer the eMundo to the bakfiets for most winter uses. The Mundo’s electric motor smoothed over the problem with the slush– while pedaling became “chunky” due to that issue, the motor could pull me along just fine without pedaling anyway.
I recently filled out the following survey questions and I thought that my readers might enjoy the answers I gave. Enjoy!
1. occupation/where work
I make websites. I founded my own company called Knowledge Town.
2. how long have you been commuting
I don’t commute to work by bicycle. I walk to work since my office is only a few blocks from my house. I use my cargo bike for errands such as shopping, taking my kids places, and long-distance travel.
3. where/when do you commute (ie. work only, other places, daily or few days a week, year round or seasonally, etc.), distance/ terrain
I use my bike three or four times a week year-round. A typical errand is 5 to 10 miles round-trip. Almost all of my trips require carrying a heavy load up very steep hills. It seems like any direction I go in Ithaca requires climbing a hill. When I step out of my front door my choices are South Hill, East Hill, West Hill and Cornell, which is on a hill to the North.
4. any advice or tips you have for new or potential commuters re: getting started, hills, winter, cargo, passengers, route planning- whatever your experience has taught you that might be helpful
If your goal is to replace your car or reduce the amount you use your car, you will need a cargo bike (a bike specifically designed to have a large cargo capacity). And in hilly Ithaca you need an electric motor for a cargo bike to be practical. And you need an electric motor connected directly to the drive chain rather than a hub motor, since this will give you the advantage of low gearing for climbing with a load. As far as I know, the Stokemonkey (described in the next question) is the only motor set up like this.
For long trips it is useful to use the Google Maps “bike button” to map your route. If you use an ebike, it is worthwhile to purchase a second battery to double your range. I am also experimenting with using a solar panel attached to my bike to increase my range.
For winter riding it is very important to put studded snow tires on your bike. It is nice to have platform pedals so that you can wear boots while riding. If you have an ebike, try using electrically-heated glove liners and sock liners hooked up to your bike battery. I used these last winter and I am experimenting with ways to make this more convenient. Also if you have an Xtracycle-compatible cargo bike you can keep your passengers warm by constructing the Bike Wagon canopy as described on my website.
5. type of bike, any accessories you find helpful (or that you’ve tried and weren’t) and why ie. panniers vs. backpack
I have a Surly Big Dummy cargo bike frame. To this I’ve attached a Clever Cycles Stokemonkey electric motor which came as a kit.
The Big Dummy frame adheres to the Xtracycle cargo bike standard, so there are many accessories available for it. I have the Xtracycle Long Tail and Cargo Van rack kits.
One advantage to an electric bike is that you have a big honkin’ battery that you can attach accessories to. My bike has very bright front and rear LED lights that are always on day or night when I am riding.
6. why do you commute by bike? what do you like about commuting?
I bike because biking is faster than walking.
(Here I must explain this answer. When people ask me why I bike they are showing a hidden bias. They assume that for me driving is the norm, and biking therefore requires some sort of explanation. For me biking is the norm. I bike because that’s how I get around. And furthermore I like to turn this question around and ask people why they drive. This often leads to a good discussion about our car culture and the damage it has done.)
7. has it changed your life in any way- how? (ie. lost weight, less stressful, have more energy, save money…)
I find that spending so much time outdoors has made me tougher, particularly my skin. I’ve noticed I don’t mind temperature extremes and being in the rain and snow as much as other people.
It would be easy to save money relative to what I spend maintaining a car. But I haven’t been trying to save money because my biking is tied up with my inventing. I have this idea that I am spending money to help other bicyclists. For example I spent hundreds of dollars and dozens of hours developing my bike canopy so that other bicyclists can build their own canopy in a few hours for about $150.
I’m at a time in my life when I’m realizing that I won’t last forever. So the biggest change in my life is that I’m doing what I love before it’s too late: biking, inventing, and going on adventures.
I recently received the following email from a reader:
I was researching cargo bikes and just kept seeing your blog pop up. I am very interested in doing a similar set up as yours. I also was interested in elMundo initially. A sidenote on the weight of the elMundo: they are now selling it with the electric components already attached and the shipping weight of the bike and box was 100 lbs. which seemed like a lot.
My question is pretty simple. I haven’t tested a Rans Hammer Truck in person since this is just the planning phase. I read the height of the bike had a 31- 38 inseam. I am 5’5″. I wondered about the comfort of the frame. And if your wife was shorter than you and found the Hammer Truck comfortable… ? Also just to pick your brain (and thank you very much in advance) how did you like the Hammer Truck handling without the electric assist? You mentioned you test rode it for a day…
My plans are just like yours, I want to use it to take my 2 kids to school and errands and fun – reduce car use in general. The kids are 6 and 4 and the bike trailer is just not cutting it these days.
Oh yeah! one more question. I read your post worrying about brakes. Currently with the bike trailer I often hop off and just walk up the hills. My question is, is a cargo bike easy to walk with when it’s carrying about 50- 60 lbs.? Or very tippy?
Thanks for the blog. I am surprised the Yuba people haven’t offered to let you test drive their bike. Surfing I ran across another cargo biker’s blog who actually bumped into the founder/owner while on a bike tour in Europe and had a very good impression of him and a good talk with him.
Thanks again. Happy biking! I am so happy I stumbled across your blog.
Thank you, Jessamin. Your email reminded me that there are still a few things I can say about the Hammer Truck. For many months, I have felt a bit uncomfortable about my bike’s relatively high cost, and I have been researching less expensive bikes that might appeal to a broader market. That has been an interesting project, and I intend to continue doing it for a while. But I don’t own these bikes or ride them on a daily basis. My real expertise is my particular bike, and answering your questions gives me an opportunity to return to familiar territory.
To answer your question about bike height, my wife rides the Hammer Truck very comfortably. At 5’4″, she is a little shorter than you. As you can see in this photo, the seat stem for the Hammer Truck is angled at approximately 45 degrees. When you lower the seat an inch, you also get an inch closer to the handle bars. This seems to scale well for most body types.
While you’re looking at the seat, I will also mention that the inclination of the seat is adjustable. When I first started riding the Hammer Truck, I had the seat almost parallel to the ground, like a normal bike. However, the Rans web site shows their seats tipped forward, so I tried it. It feels a bit like standing and leaning against a wall. Tipping the seat puts a little more weight on your feet, and that’s what you want when you’re riding. The slight curve of the seat back allows you to dig in for a little extra leverage when you need it. These are all helpful when you really need to crank!
The Hammer Truck worked fine without the motor. If we still lived in Denmark where it’s notoriously flat, I wouldn’t have needed the electric assistance. I’ve spent so much time on this blog bemoaning the hills in our neighborhood, I decided I really needed to show you what I mean. Yesterday afternoon, I put my 9-year old son behind the camera, and he took a video of me pushing my daughter up the hill, riding without assistance, and riding with the motor providing maximum assistance.
As you will see, this hill is a monster. When I write about heating issues with my motor and brakes, you need to understand that I’m pushing both to a limit that most people won’t encounter. Despite my occasional complaints, it’s pretty amazing that this bike can handle this kind of challenge. (Note: the scraping noises heard in the video aren’t the bike — my son was balancing the camera on a mailbox to keep it level, and scraping as he pivoted the camera.)
You can also see from the video, pushing the bike uphill is possible, but not fun. The side bars that carry loads so well are approximately where you want to put your feet, so you have to lean over a little. It might be hard to see in the video because I’m already leaning against the hill so much. It’s not as tippy as I thought as long as both hands are on the handlebar. It would be almost impossible to do one-handed.
You might notice my slightly hunched posture when I’m riding in this video. With the Hammer Truck, you generate power by pulling back on the handlebars, engaging the same muscles you would for rowing. In my case, I can produce more cranking force this way than I would standing on my pedals on a traditional bike. It’s more of a full-body workout, especially when I turn the motor off. However, this might not be a good idea for people with fragile knees.
Speaking of cargo bikes on hills, this is probably a good place to mention one of my favorite web pages: Cargo Weight Calculator. The calculator which gives you a rough idea about how much weight you can expect to haul up hills of varying steepness. Another page on the same site shows you how to measure the grade of a hill. Every time I turn off my motor and I’m reminded how hard it is to climb a hill with a load, I return to this web site, punch in the numbers, and I’m assured that there are real, mathematical reasons why it’s difficult. It’s not because my motor is making me lazy. 🙂
Sometimes I get distracted by all the details of this project: the specifications, the prices, the compromises. My blog is kind of heavy on that sort of thing. I occasionally need to remember that there is an emotional and even inspirational side to cargo biking, and my favorite blend of practicality and inspiration comes from the Couch Potato to Full-Time Cyclist blog. If you haven’t seen it, check it out — it’s really a great counterpoint to what you read here.
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.
Just for fun, here are a few numbers I measured this morning, in an effort to make my blog a little more precise:
70 pounds — the unloaded weight of my Hammer Truck, battery, motor, bags, lights, etc. That’s actually somewhat heavier than I expected. And that doesn’t include the canvas shopping bags, rain cover, bike lock, water bottle, bungee cords, and other things I keep in the side bags for easy access. No wonder I feel a little weak when I turn off the motor (only occasionally) and try pedaling up our hill.
30 pounds — the weight of my non-powered bicycle for comparison. But I almost never ride it if the cargo bike is available.
10% grade — the incline of the road in front of our house.
18% grade — the incline on the steepest section of road on our way to school every morning. It lasts for about 100 yards. When I’m hauling a 70-pound kid and 20 pounds of books and instruments up that part of the hill, the motor and the human are both close to their limits. This is when you begin to appreciate the miracle of cars. Just press that accelerator a bit more towards the floor, and 10 times the mass of my load leaps up the hill at 5 times the speed. But that challenge only lasts for 100 yards, and most people don’t have 18% inclines in their daily routes. The 10% grade feels more reasonable, as you can see in the first part of my Electric Cargo Bike video (http://mycargobike.net/2010/05/06/cargo-bike-video), where I haul my son and his stuff around the corner and up the hill.
7 months — the length of time I’ve been riding my bike down that hill, often with two kids as passengers, without any brake replacements or adjustments. I think that is the best aspect of the BionX regenerative braking system. I’m just beginning to think that an adjustment might be necessary in the next month or two. My wife wore the brake pads on her traditional bike down to the metal in that same span of time.
Good news: I’ve found an owner as well as two local bike shops who have the Kona Electric Ute. I hope to take it for a test drive this weekend at a local sustainability faire!
If a picture is worth a thousand words, I’m guessing a video is worth at least a hundred pictures. I’ve been wanting to make a video showing the bike in action for months. Now that I have, it won’t win any awards, but hopefully it will give you an idea of how the bike works and how it sounds (silent motor, squeaky brakes!)
It has been a couple of months and a couple hundred miles since my last post. I really intended to update my blog more often than this, but it’s more fun to ride my bike (even when the errands are rather mundane) than to sit in front of my computer. However, there have been many ups and a few downs since November, so I will try to catch my blog up.
The Hammer Truck continues to be a great bike for us, and I owe you another post or two to describe some of its features. But it’s really the electric motor that makes the whole thing practical and fun in our abundantly hilly neighborhood. On the flip side, the electric motor has also been the source of a few challenges.
Our motor is the BionX PL-350, with a retail price close to $2000. I haven’t done a thorough comparison of different motors, but this one seems like it’s optimized for biking enthusiasts. It’s relatively lightweight, very quiet, and supposedly maintenance-free. But the features that really set it apart are torque sensor activation and regenerative braking.
Torque activation feels really cool when it is working the way you want. The system senses the amount of torque you are applying to your pedals, and it kicks in additional power from 35% to 300% of your torque. You determine how much assistance you want by selecting one of four assistance modes on the handlebar controller.
Regenerative braking allows you to reduce your speed and put some charge back in your battery while extending the life of your brake pads. There are 4 generation modes that increase the drag on your back wheel and put increasing amounts of electricity back in your battery. There’s also an option to activate the highest generation mode when you start to apply your rear brake. I really like that feature.
Pros and cons of electric assistance
During the first week or two, I rarely used anything but the maximum assistance mode (level 4, 300%). It’s frankly thrilling to blast up pretty steep hills at 10 m.p.h., to sprint away from stoplights as fast as most cars (at least until they shift!), and to haul kids around with less effort than going solo on my traditional bike.
With more experience, however, my strategy has become a bit more nuanced. Assistance level 1 (35% additional torque) makes the unloaded Hammer Truck feel like an average weight bike. It’s great for level ground or a light head wind. Levels 2 and 3 are good for moderate hills when I don’t feel the need for speed.
For a while, I was fiddling with the regenerative levels a lot. I would sometimes put it in a high regenerative mode and pedal downhill, reversing the direction of my battery meter by a click or two. However, one day when I was doing that, the rear wheel suddenly locked up. After some investigation, we found that I had shorn off the axle nut of the rear wheel. After that, I’ve been quite cautious about pushing the limits of this bike/motor combination. Since the motor wasn’t especially designed with a loaded cargo bike in mind, and since the bike wasn’t really designed to be motorized, and since our hill probably puts us in the 90th percentile of steep neighborhoods, I’m feeling that extra caution is probably the best course for now.
When you match the power mode to your legs and an appropriate gear on your chain-ring, the reward is great. With each stroke, you feel a surge of power, as if Lance Armstrong’s legs have been grafted onto your body. In power mode 4, you might be even better than Lance! It’s a beautiful marriage of man and machine – the kind of thrill you had the first time you rode your bike faster than you could run.
However, this is a great solution only for someone who likes to bike already. It’s not a moped! It works best when you’re putting in some effort yourself, not just coasting along and letting the motor do the work for you. As a matter of fact, if you’re not pedalling, the motor isn’t working either.
I spend a lot of time in my higher gears, even going uphill. Since the torque I’m exerting is pretty high, the motor is putting in a high level of effort as well. If I get tired and shift to a lower gear, the motor seems to scale back as well, so I end up going slower with only slightly reduced effort.
Once mastered, the combination of Hammer Truck and BionX motor enables many kinds of errands by bike. It extends your speed, your practical distance, and the amount you can comfortably haul. And of course, it’s fun – I look for any excuse to get on my bike now.
But is this the bike that will get millions of people out of their cars? I don’t think so. It’s a little quirky and the learning curve is a bit steep. Although it’s a good first step, the ultimate bike will be designed with an integrated motor from the outset. There are already a number of electric bikes in a traditional form factor. I haven’t seen a cargo bike with an integrated motor, and we may have to wait awhile for that. For now, this is a pretty good alternative to a second car for many of our errands.