The Making of the K15

By Bill Moore

It may be the lightest electric-assist bicycle of its type anywhere. Weighing less than 15 kilograms, it also will be EV World's first e-bike offering in more than a decade.

For more than 17 years, I have written about other people's electric vehicle projects. This time I going to tell you about mine.

It's called the K15. Pictured above, at 31.6 lbs. (at least, according to my wife's bathroom scale, which of course, never lies), it is the lightest electric-assist bicycle of its type anywhere. I thought EV World readers would find it interesting how it came to be and what my plans are for it.

EV World actually came into existence because of an electric bicycle. In the summer of 1997, while visiting my local bank, I picked up an old copy of Business Week magazine and came across a two-page advertisement for the Warrior electric bicycle, a collaboration between Dr. Malcolm Currie and Malcolm Bricklin. Currie was the former head of Hughes Electronics and Bricklin, of course, is a serial automotive entrepreneur.

Intrigued, I wrote down the company URL and headed for my local library where they had an ISDN connection: at home, I was still using a 28.8 dial up at the time. I would spend the next couple hours learning about the world of electric vehicles, especially the exciting rollout of EVs in California. That fall I decided to launch EV World and attended my first Electric Vehicle Symposium in Orlando, Florida. There I got to drive my first Toyota Prius, introduced in Japan only 12 days earlier, as well as drive GM's EV1 and other electric cars and pickups from the major OEMs. I also got to meet a dedicated and fun cadre of EV hobbyists and enthusiasts. On January 1, 1998, EV officially went live.

It was maybe a year later that I bought my first 'electric vehicle,' a Currie folding electric bicycle. In 2000, I bought my first hybrid, a Honda Insight (serial number 984) , which I kept for 10 years, eventually replacing it with a 2009 Prius. My next electric bicycle came through a barter arrangement with Wavecrest Laboratories in McClean, Virginia, who provided me with an early prototype version of their TidalForce M750.

The M750 is still an amazing e-bike. Its 750W rear hub motor is Ninja silent, something that was a revolution for its time in the early 2000s. Based on then state-of-the-art NiMH battery chemistry, it was and remains an amazing technological feat. Unfortunately, the company didn't survive, but my M750 has. I still ride it.

However, it has one major drawback. It is heavy as hell. Close to 60 pounds, it's a bear to lift; but so are most other electric bicycles, which tend to weight in the high-40s, low 50-pound category.

That's why I am so excited about the K15, but building the lightest e-bike of its kind wasn't my original intention.

About two years ago, I heard, via Hannes Neuport of ExtraEnergy in Germany, about the BIKE+ all-in-one motor by ZeHus s.r.l. Here was a compact, 250W hub motor that didn't require an external battery or controller. This was before the explosion of media interest around the Copenhagen Wheel. Intrigued, I started a Skype conversation with Giovanni Alli, one of the co-developers, in Milan, Italy. In the back of my mind, I thought this was a motor that I could do something with. Exactly what, I wasn't sure.

Over the following months, I kept in touch with Alli and the team at ZeHus, whose roots are in Milan Polytechnic University, periodically reporting on their progress via EV World's newswire.

Then last September, I attended Interbike in Las Vegas and had the chance to actually try out the motor on the test track behind Mandalay Bay Hotel and Casino. I was immensely impressed, not only by the amount of torque and the regenerative braking feature that occurs when you back pedal the bike, but also the fact that you control the motor with your smartphone. Yes, there's an app for that, both for iOS and Android.

Zehus Bike+ smartphone app
ZeHus app showing screen for setting the level of electric assistance: far left in full-assistance, far right is zero assistance. Bike+ mode also has a 'mountain' setting for riding in more hilly terrain.

Last Fall, I decided that I wanted to get ahold of one of the motors to begin testing it in the "real world." Riding around a flat track in Las Vegas isn't the same as the hills here in my hometown. ZeHus agreed to sell me a motor with the understanding that it was for testing purposes and that I was intending to become a manufacturer.

They did me no favors on the cost: I'd paid the full price for it since I was ordering only one unit. I arranged with my local bank to do a wire transfer to Italy and had DHL airfreight to me. It arrived two days before Christmas.

While I was working on getting the motor, I was also looking for a suitable 'mule' on which to install the motor. At first I thought I'd just buy a cheap used bike off Craig's List or from one of a half dozen pawn shops around town. They always seem to have a stable of used bikes parked out front. ZeHus advised me that I needed to make sure that whichever bike I ended up using, it was vital that the distance between the rear drop-outs, that's where the rear wheel mounts to the frame, was precisely 120 mm. I made a plastic cutout 120 mm in length that I carried around in my wallet to measure various bikes.

However, before I actually bought a bike, someone alerted me to a company in Minneapolis called Greenstar. They had a beautiful bamboo and aluminum bike for sale at a very reasonable price as bamboo bikes go: less than $500. Now that was way more than what I was originally expecting to pay since I was only wanting something on which to test the motor. But the idea of a bike made from sustainable bamboo and recycled aluminum really struck a chord with me.

I had previously read William McDonough and Michael Braungart's 'Upcycle,' The sequel of 'Cradle to Cradle,' they argue that with forethought we can actually create products that get better when they are recycled, or "upcycled." It was about this time that I started to think about an electric bicycle based on the upcycle principle. I even approached CocaCola with the idea of creating electric bicycles from "upcycled" aluminum pop cans and renting them to tourists. The proposal never got past middle management, but the seed had been planted in my mind.

So, when I saw the Greenstar Ecoforce 1, I contacted Eric Hiller in Minneapolis and he agreed to sell me a bike at dealer cost. It arrived two weeks before Christmas.

My first tip-off that I had something special on my hands is when Fedex left the box, unannounced, on my front porch. Used to manhandling my M750 and other conventional, but somewhat lighter e-bikes sent to me to test, I expected this bike to be of similar mass. What I picked up was so light that at first I wondered if they'd sent me an empty box. At 20 lbs., the Ecoforce 1 weighs one-third that my M750 does.

Not only was it surprisingly light, it was just downright beautiful. I'd selected the green frame and wheels (the bike also is available in white and sky blue) but the green, to me, just sent all the right signals. Against the warm, honey-toned bamboo, it is just stunning. As one person on my Facebook page commented, "It's not a bike. It's a work of functional art."

Also, in case you weren't aware, pound-for-pound, bamboo is said to be stronger than steel.

Like most bicycles in the world, this one is made in China to Greenstar's specifications. It is single speed with a hybrid configuration that blends mountain bike-style handlebars with a road bike-type frame. Its lines are clean and clutter-free. The wheels are 700C by 23 mm on aluminum rims. It is the essence of minimalism: a perfect blend of form and function.

Now with both bike and motor now in hand, my next task was to find a bike shop that would 'lace' the BIKE+ to the rear wheel. Originally, Sarah Johnson, the owner of Omaha Bicycle Company, agreed to do it in her shop in Benson, but only if the motor arrived before her technician left on an extended bicycle tour across the American southwest. It did, but a death in the family compelled Sarah to close her shop on Christmas Eve. So, I picked up the bike and motor and eventually found a shop that would take on the project. Interestingly, a couple other shops I called refused to do it on principle.

"We don't mount motors on bicycles," one of them told me, with a hint of indignation.

But one did, the Bike Rack in west Omaha. Their lead technician, Kelly Smith was terrific to work with and before New Years he had the bike ready to go. Before we rolled it out of the shop, he weighed it. His scale said it was just over 32 lbs, or less an 15 kg. I'll come back to the number in a minute.

I got the bike home, took a bunch of digital photos, especially of the motor mounting and emailed them to ZeHus. Almost immediately, I got a reply, asking me if I had installed the locking bracket that came with the motor.

No, I hadn't, I replied. Kelly thought the steel dropouts were plenty strong to support the motor.

It is vital that the bracket be installed, ZeHus cautioned me. It is what makes our system work.

Okay. Back I went to the Bike Rack and few days later, Kelly called to say he'd installed the required bracket.

Near as I can tell, and this part is obviously proprietary, making certain that the motor can't torque under load is critical to the embedded software algorithms that control the system. In fact, when I installed the newest version of firmware on the motor, I had to insure that the bike was perfectly level during initial set up. I am guessing here, of course, but there must be an inclinometer in the motor that senses the bike's angle of elevation and uses that to determine when and how much electric assist to provide.

The BIKE+ motor operates in European pedelec mode, meaning there is no throttle. You pedal the bike just like a regular bike and sensors determine, based your smartphone app setting, how much assistance to provide, ranging from full E-bike mode to no assistance.

The BIKE+ mode, as seen on the above app photo, allows you to ride the bike indefinitely without ever having to plug it in to recharge the battery. Think of like a Toyota Prius. In full E-Bike mode, the 160W/h Boston Power lithium cells are good for at least 10 miles, actually about the range of the Prius Plug-In model. You recharge the battery through a small connector housed inside the motor shaft. Your smartphone talks to the motor via Bluetooth, which you activate by a few quick turns of the wheel. The app also shows distance traveled, degree of incline, battery-state-of-charge, and speed. You can even lock the motor internally with the app for added security. As long as there's a charge in the battery pack, which is wrapped around the motor, the bike is going nowhere.

With the bike now assembled, I wanted to start testing it only for the weather here on the Great Plains to turn polar for weeks on end. But every now and then, I had the opportunity to let various people ride it to gauge their impressions. Time and again I was told, "Bill, you need to produce this," or "Where can I buy one": the latter just yesterday from two local multimedia producers, who took it around the block and came back beaming.

I have also used the bike to help convince state and city officials to allow e-bikes that meet federal standards on bike paths where 'motorized vehicles' are not permitted. In fact, the bike is only the second bicycle ever allowed inside the Nebraska state capitol building, I was told. The first one was a Currie iZip Path that I borrowed from the University of Nebraska Omaha to show to state legislators during testimony on a bill I helped initiate in 2014. That bill, revived in 2015, was signed into law in late February. It defines qualified e-bikes as "bicycles."

Last week, after showing the K15 to city officials in neighboring Council Bluffs, Iowa, their City Council approved a revision to their ordinance also now allowing e-bikes on their bike trails.

All this brings me to the decision to crowdfund the production of an initial 150 models of the bike, which I am now calling the K15 because it weighs under 15 kilograms and because 'BambooZal' just didn't click for me, for obvious reasons.

The idea is to use the bike as a way to help fund the development of my first Q•Pod electric bicycle rental pop-up shop. I'll tell you more about that project in the future. The K15 will be one of the 'premiums' offered to crowdfunders. I hope to launch the campaign this coming month.

Yesterday, I used North Sea Film's white stage to shot still photos, which you can see here, as well as B-roll video footage of the bike. Monday we shoot the crowdfunding video. My goal is to raise $300,000, most of which I hope to generate by taking orders for the K15s. After delivering the first 150 bikes, I aim is to have enough left over to convert our first repurposed shipping container into a solar-powered rental shop.

As you may be aware, some crowdfunding campaigns have been wildly successful: Sondor raising an astounding $5.3 million for a Chinese-made fat tire cruiser. I don't expect that level of response, especially since the K15 isn't being billed as the 'cheapest' electric bike. What it is, is maybe the lightest e-bike of its kind anywhere.

What I am hoping is that EV World readers will talk it up, share the link, tell the story, and help us "go viral." And maybe a few will even want to place a early order: see the pre-reservation form on the page. The success of the campaign rests a lot in your hands. You can help make it hugely successful, allowing us to fulfill Quikbyke's mission of getting more of us off our car seats more often and onto bicycle saddles for "Fun, Fitness, and Saving Planet."

Are you ready to come "Ride the Current"™ with me?

Times Article Viewed: 79465
Originally published: 28 May 2015


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