13
Oct 2010
by don

Third generation electric cargo bike

I worked in the computer industry for three decades, so I am accustomed to the furious pace of innovation associated with that enterprise.  Even so, I have been surprised by the pace of development of electric bikes in general.  While competition in the electric cargo bike category has been a little less fierce, it’s amazing that we’ve witnessed three generations of development in a little over a year.

The first generation of electric cargo bikes were do-it-yourself jobs.  Customers had to pick a bike and a motor, put them together, and hope the marriage would be a good one.  That’s what I did with my Rans Hammer Truck and BionX motor, and as you probably know, I’m pleased with the result.  But there are quirks and compromises that I have to warn people about when they take my bike for a test drive.  There are issues (like a non-existant gear) that wouldn’t be tolerable on a bike that was manufactured with an integrated motor.

I’ve written extensively about the second generation of electric cargo bikes.  These are cargo bikes that come with an optional motor from the manufacturer, like the Kona Electric Ute, Yuba elMundo, and Trek Transport+.  Each of these bikes is available in assisted or non-assisted versions.  The motorized versions reduce the guesswork and installation labor compared to the preceding generation.

I’ve frequently mused what a third-generation electric cargo bike would look like.  What if a manufacturer, instead of adding a motor to a non-assisted bike, decided to start from scratch and design a bike that integrated electric assistance so fundamentally that it defined the essence of the bike?

Several days ago, I got my first answer to this question from a Dutch company named Urban Arrow.

Urban Arrow

Let me just say it: I’m very excited about this bike.  Just in case my exuberance gets ahead of my experience, I’d like to be clear why I’m excited about it.  It’s not just about what the bike is, but what it represents: a preview of where I expected electric cargo bikes to be in another couple of years.  If the company manages to sell this bike next year at their current price target, the market is maturing faster than I imagined.  Either that or they are a little ahead of where the market opportunity is today.  It will be fascinating to find out.

I will caveat my remarks by acknowledging that I’ve never ridden this bike or seen it in person.  Since Seattle is pretty far from Amsterdam, I don’t know when I’ll have that pleasure.  However, the Urban Arrow won an Innovation Award last month at the Eurobike Show in Friedrichshafen, Germany.  So at least I’m not alone in my appreciation.

Without further ado, here it is:

Urban Arrow

Yes, it’s a front loader – the first with integrated electric assistance that I’m aware of.  As I’ve said before, front loaders are common in Europe, but they look pretty strange to North Americans who may have never seen one in person.  Despite the unusual configuration, a front loader is really what you want if you’re transporting young children.  With a lower center of gravity, their wiggles won’t disturb the equilibrium of the bike as much.  In a worst-case scenario, they won’t have as far to fall.  It’s also comforting to have them strapped in a sturdy box and under their parents’ watchful eye.  Furthermore, when the weather turns wet, you can do this:

Urban Arrow with cargo cover

I can’t imagine a kid who wouldn’t be thrilled to ride in that cozy compartment.  There really isn’t a comparable way to shelter your kids on a longtail bike.  The cargo box features a bench seat (which hides the removable battery), 2.5″-thick high density foam for comfort and safety, a grocery net, and even cup holders!  The box can be removed to convert into a flat-bed cargo bike, although I’m not sure how simple that is to do.

Groceries and passenger in the box

Most front loader bikes are heavy – between 70 and 100 pounds, and that’s without a motor or battery.  The Urban Arrow uses an aluminum frame to keep the weight under 100 pounds including the motor and battery.  That’s not exactly light compared to the longtails I’ve reviewed, but it’s prepared to handle some serious cargo.  The company claims it can carry up to 400 pounds in addition to the rider.  As usual, I wouldn’t want to test those limits, especially coming downhill.

Although the company doesn’t refer to the angled seat stem and forward pedals as a “crankforward” design, it’s closer to the posture of my Hammer Truck than the other bikes I’ve reviewed.  I’ve described the advantages of this design in previous articles, but perhaps the main advantage is reduced step-down height.  You can get your foot on the ground while seated without tipping the bike and your cargo too far.

Motor and transmission

Daum crank motor and chain

The Urban Arrow is assisted by a 250-watt motor manufactured by the German company Daum.  In previous articles, I’ve faulted the Electric Ute for using a 250W motor, which I felt was inadequate for carrying cargo uphill.  But even though the power rating is the same, there’s a critical difference between these bikes: the Ute has a hub motor, which typically produces less torque at lower hill-climbing speeds.  The Arrow’s motor is connected to the crank, and it drives the wheel through the transmission – just like your legs.  If the motor is beginning to fade at low speed, you can simply shift to a lower gear to increase cranking speed and get closer to the motor’s optimum torque range.

Stoke Monkey motor

This idea isn’t new.  Cargo bikers have been using Stoke Monkey motors to drive their cranks for years.  But the Stoke Monkey requires an extra chain to drive the crank, and another extra-long chain to drive the rear wheel of a longtail bike.  If you’re the type that likes to lubricate and adjust chains in your spare time, a Stoke Monkey might work for you, but it’s not a solution that is likely to appeal to the mass market.

The Urban Arrow’s design avoids another pitfall of the Stoke Monkey: shifting under power.  If you’ve opened up the throttle on your Stoke Monkey and then try to shift, you have at least 2 times the strength of your legs ready to grind through your derailleur and gears.  The Arrow uses a Shimano Nexus 8 transmission to dispense with the gears and derailleur.  Besides easier and more reliable shifting, the Shimano hub allows you to shift even when you are stopped or under load.  That makes shifting one less thing to worry about.

Urban Arrow in urban setting

Eight gears seems adequate with motor assistance.  I have 21 gears on my bike, but I only use the top 3 or 4 of them when the motor is helping.  However, if you want to carry cargo over hills beyond the bike’s battery range, eight gears might not be enough.  The company claims an assisted range of over 30 miles, but I suspect those are relatively flat miles in Holland, not Seattle hills.  Battery capacity is 36V at 9.5 amp-hours.

Like almost all the electric cargo bikes I’ve reviewed in previous blog posts (with the exception of the Yuba elMundo), motor effort is controlled through a torque sensor which measures how hard you are pressing on the pedals, and then kicks in a proportional amount of assistance.  I prefer this method to a manual throttle.  Twisting both a throttle and a gear shifter is more than I care to think about when I’m negotiating traffic and road hazards.

To comply with European law, the motor is only allowed to assist up to 15 mph.  In my opinion, that is a bit conservative, but probably wise.  Especially when people are carrying kids, we shouldn’t encourage them to exceed that speed.

The drive chain of the Urban Arrow is nicely enclosed to keep it away from clothing and small fingers.  It’s a great feature enabled by the internal hub transmission.  I would still like to ride a chain-less bike someday, but this is a nice step in the right direction.

Daum display

Assistance level and a wealth of other information is displayed on the large Daum control panel.  Apparently, it will even measure your heart rate if you’re riding for fitness.  A premium version includes GPS (for a premium price).  That could be useful for rental bikes, letting the rider know where they are, and helping the rental company to keep track of their bikes.  If a bike is stolen, the GPS unit can tell you where it is via SMS messages.

Brakes

Shimano roller brake

When I saw the first photos of the Urban Arrow, I was excited to see disc brakes on the front and rear wheels.  A company representative soon corrected my false impression: the disc-like features on the axles are actually cooling fins for Shimano roller brakes.  The company deliberately chose roller brakes rather than disc brakes to reduce the possibility of skidding.  Having experienced the dangers of skidding with a heavy load, that sounds good to me.  On the other hand, will these brakes handle the long, steep incline that heats my disc rotors to the point of scorching?  I don’t think Holland has hills like that, so the performance of these brakes on steeper terrain is still a concern for me.

When you look closely at the front wheel, you see something next to the roller brake fin.  At first I thought it was a hub motor: it’s nearly the same size as the Ute’s motor.  But it’s actually a hub dynamo.  It produces electricity as it spins.  At first that seemed odd to me – you’re spending electricity on the back wheel to produce electricity on the front wheel.  Fortunately, my contact at the company cleared up the mystery.  They need the hub dynamo to determine how fast the bike is going so they can keep electric assistance within legal limits. 

Lights

Excess electricity from the dynamo will be used to power the Arrow’s front and rear running lights.  For increased safety, I’d be willing to accept a little drag on the front wheel even during daylight hours.  I’m not sure what happens at night before you achieve sufficient speed to fully power the lights.  I would be tempted to put Down Low Glow light tubes on either side of the cargo box to enhance visibility from the side in the evening.

Videos

The videos and slideshow below require Flash and won’t be visible if you’re reading this article through my email feed.  If you would like to see them, click here to open the article in your browser.

The video below shows the Urban Arrow carrying kids.  It’s in Dutch with English subtitles.

The next video is a review of the bike by a Dutch technology reporter.  Unfortunately, it’s all in Dutch with no translation.  I included it here because it contains two interesting clips.  In the first, the rider performs a U-turn with the bike.  That’s one drawback of the front-loader design; the rod that turns the front wheel prevents sharp turns, so a short-radius U-turn requires some back-and-forth.  The second clip compares hill climbing with and without motor assistance (he thinks that is a hill?!? :-) )  I couldn’t hear any difference between the two, raising my hopes that the motor is as quiet as the company claims.

Price and availability

The company is aiming to start selling the bike in the U.S. in the second quarter of 2011 for around $3700.  That’s at least $1000 more than the motorized longtails I’ve been reviewing, so that alone might narrow the market for this bike.  On the other hand, it’s in the ballpark of similar front-loaders without a motor (like this Bullitt from Splendid Cycles).  If you’re looking for a kid carrier, the Urban Arrow would be a good deal at that price.  The rain cover will add about $250.

Price is just one factor that will determine the success of the Urban Arrow in the U.S.  I’ve already wondered how this bike will perform on steeper hills, but there are plenty of places in the U.S. where the landscape is more forgiving.

I think the bigger question will be dealer support.  If I were going to invest thousands of dollars in a bike like this, I would want a reliable and knowledgeable bike shop nearby who could maintain and repair the bike, when necessary.  I’m guessing that few bike shops in this country would be familiar with Daum motors, and although Shimano is a well-known name, experience with roller brakes may also be sparse.

I’m hoping that some American bike shops will start selling the Urban Arrow and specializing in its upkeep.  A really savvy shop could alleviate customer concerns by offering free pickup of a disabled bike.  Even if the bike is your “second car”, getting its 8-foot length into or onto your first car could be a challenge.  By way of comparison, loading my 7-foot Hammer Truck into our mini-van is pretty tight, even with the back seats removed.

Final thoughts

It’s ironic that a bike I’ve never seen has inspired me to write a longer review than one I’ve actually seen and ridden (like the Electric Ute).  I’ve never felt comfortable writing about a bike that I’ve only met in cyberspace, but I’ve done it before when I felt it gave a better idea of the range of options and where the market is headed.  That reasoning justifies this article because the Urban Arrow breaks new ground in several ways.  It’s a harbinger of a new generation of bikes, and I’m excited about that possibility.  I hope other third-generation bikes are around the corner rather than years away.  If I get a clue, I’ll be happy to let you know.

The Urban Arrow is enough of a leap forward, I can’t stop myself from wondering what a fourth-generation bike would be like.  In my opinion, the next major advance will be some sort of automatic transmission.  As I’ve mentioned in a previous article, truly practical human-assisted transport will isolate rider effort from the terrain.  Someday, a rider will pedal at a steady, comfortable pace, regardless of whether they are going uphill or down, and biking infrastructure in our cities will become more accomodating as riders of all ages and fitness levels discover they can participate in this revolution. 

If nothing else, the Urban Arrow gives me hope that this vision is still achievable and on track.

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  • RickS

    Thanks for all of the great information! It’s nice having you keep an eye on things that I may miss. I don’t think I will want a front loader like this but things are moving in a good direction.

  • http://keller74.wordpress.com Mark

    Thanks for that. I think the forward load design looks good in places with good cycling infrastructure but I get the feeling manoeuvring it around a cycling unfriendly city like Sydney might be tougher than with a long tail. But I do love the integrated design of this bike.

    I love the fact that the second reviewer has to use a man made “hill” to test it climbing ability.

  • http://mark.stosberg.com/bike Mark Stosberg

    Thanks for the review.

  • Alisdair Richter

    Looks good, but I’d be tempted to wait until Harry vs. Larry finally produce the electric version of their Bullitt – the prototype’s been floating around for over a year now. Maybe they’ll finally pull their finger out now that the sales of electric bikes have risen by more than 30% during the last 12 months. And that’s despite the fact that the choice on the Danish market is hardly what you could call extensive.
    I have to admit that the Urban Arrow also seems to have their box/weather gear sorted, something that not on the Bullitt. A bit strange when you consider that it’s designed in Denmark; where we have more than our fair share of foul weather.
    Roller brakes? The dutch manufacturers are more than a little bit obsessed with these, sticking them on everything. Personally I would be happier with discs. Lighter and easier to service.

    • http://mycargobike.net Don

      I would love to see an electric Bullitt, but at least here in the U.S., price would be a concern. The unassisted Bullitt is already more expensive than most of these electric cargo bikes. I guess the weak dollar isn’t helping that situation.

  • http://clevercycles.com/ todd

    Great writeup! We are keeping a close eye on these bikes, too. If they are as good as they seem, we hope to import them. You are right to allude to Stokemonkey as an example of the benefit of running a low-power motor through the bike’s variable gearing, though I’m puzzled why you link that product to derailleur systems, when my personal stoked rigs have all had internal hubs (Rohloff, Nexus 8, NuVinci), 2 with chaincases, and even in this format: http://clevercycles.com/2006/11/08/stoke-your-bak/ . There are a few stoked bakfietsen rolling around, upgraded to the IM-80 Roller Brakes shown on the Urban Arrow: they work great. As for dynamo hubs, I can assure you that drag is not noticeable even on a much lighter bike, so this isn’t a misguided case of trying to rob Peter to pay Paul.

    • http://mycargobike.net Don

      Thanks, Todd. I feel honored when people who really know their stuff enrich my blog with their real-world experiences. You are welcome any time!

      Of course, you’re right; the Stokemonkey doesn’t preclude use of internal hubs. In fact, I came very close to buying a Big Dummy with a Stokemonkey and a NuVinci hub, before the Hammer Truck/BionX combo stole my heart :-) . On my steep hill with pretty sizable loads, I was a bit nervous about the extra wear and tear those expensive hubs might experience. But my hub motor has taken the abuse without any problems yet, and it would be even more expensive to replace. So maybe I didn’t need to worry about that.

      Can you tell me more about roller brakes with a load on a steep incline? I’m convinced they would work well on average slopes, but I’m wondering if those of us with bigger hills would miss our disc brakes. I don’t know if that’s a scenario that can be fully tested in Amsterdam.

  • http://clevercycles.com/ todd

    There are several models of roller brake, Shimano’s implementation of a drum brake. The lower-end ones (IM-40, IM-50) have no or only small heat sinks to absorb braking energy. Not the best choices for extended steep cargo use. The original bakfiets.nl Cargobikes were equipped with these. Probably about 10% of people who bought them remarked the softness of the brakes here in not-so-steep Portland. We also noted quite a bit of variability unit to unit; never could tell why. But often simple replacement of one IM-40 with another improved braking dramatically. We heard a handful of crash reports from people who either had electric assist or otherwise used motor help to get up steeper hills than they could pedal the bikes, when the brakes seized on the way down. I was one of them! No injuries beyond raspberries, but not OK.

    Model IM-70 has the same internals as the aforementioned ones, but quite a massive heat sink, and more leverage: a stronger brake more suitable to hills. These are standard on more recent bakfiets.nl Cargobikes. No reports of crashing or poor performance after 2 years or so in non-flat places.

    Model IM-80, pictured above, has much more robust internals and a big heat sink combined. When we saw it on the Urban Arrow, it told us they were serious about stopping. We have upgraded 2 assisted bakfiets.nl Cargobikes to these brakes. No complaints. What we haven’t done is conducted stress tests to determine how much is too much. So I can’t compare them to this or that disc system. But about rollers versus discs in general: rollers are virtually maintenance free, even stored outdoors in icy or salt conditions, less prone to wear and maladjustment than discs. It’s a self-centering steel-on-steel braking interface, greased and weather sealed, not composite pads on exposed steel like discs. They have a more progressive feel than many discs, making dangerous lockups less likely.

    Our wariness about the high-speed braking characteristics of bikes in this format is why we never pushed the assist concept with them. It’s not just the brakes per se, but the lightly loaded front wheel without a big load, and the relatively small amount of rubber on the road relative to the total kinetic energy of the vehicle. The crashes didn’t happen from not being able to stop the wheels, but when the wheels did in fact stop and the tires lost purchase. Large footprint lower-pressure Big Apple tires, modest motor power with a sensible speed limit, relatively low vehicle mass: these are more reasons to be optimistic that Urban Arrow might be “the one.”

    • http://mycargobike.net Don

      Wow, that is really great information. Thanks for taking the time to share it. I hadn’t thought about the light weight on the front tire when a front loader isn’t loaded. Very interesting!

      The roller brakes intrigue me. I would love to try them someday on my half-mile hill and compare them to my disc brakes. It might not be the ultimate torture test, but it’s definitely a challenge.

  • http://www.totcycle.com Julian

    Hi Don –
    Just (finally! you’re just across the lake) read your blog from finish to start. Loved it! We seem to be ending up in a very similar mindset about cargo biking with family in hilly, wet Puget Sound.

    I’ve gotten my feet wet with e-assist with a Clean Republic ProPack (front planetary lighter-weight hub, spokes, you build the wheel, very simply pushbutton on/off “throttle”), chosen for low entry cost ($469 including lithium, battery pack) and their offices are in Seattle.

    Has the usual “1st-gen” issues – difficult disc brake compatibility, throttle malfunctioned when soaked, need to be a bit of a tweaker/tinkerer to get things sorted, etc. But by and large, even with only 250W, it has been very exciting to have increased range, and comfort with larger loads and hills. And to see my previously somwhat reluctant wife take to hauling the kids. Have used it briefly on our MADSEN, now on our xtracycle until the disc brake issues get sorted.

    But I agree with you that Urban Arrow and other electric-by-design solutions will be worth the extra cost. Only quibble is wondering about the durability of the box on this one. Can’t wait to try it though, hope Clever gets them in. And hope to demo a Bionx Bullitt next time I’m down in PDX. Sounds like you guys would enjoy a trip down on the train to visit Todd and Joel!

    • http://mycargobike.net Don

      Greetings, neighbor! I just checked out your blog and it is great, great, great! I can’t believe I didn’t find it earlier. You have a lot of experience with kid-carrying which I will reference in a future blog post. And I loved your survey of the kid transport cargo trikes that are available.

      I especially appreciated your encouragement at this dark, wet time of year when it seems like much of the cycling public (and industry) has gone into hibernation. I’m riding significantly less right now for a variety of reasons (which I will detail in my upcoming New Year status report). It feels so luxurious to get on my bike these days, I appreciate it more than ever.

      We love taking the train down to Portland, and our next trip will definitely include visits to Clever Cycles and Splendid Cycles.

  • Kerry

    What they need to do is to use a cvt transmission. It keeps the torque range nearly continuous throughout the ride.

  • agzweiner

    Fantastic review/distillation of the cargo bike state of affairs. Thanks!
    Just wondering… you posted this extended and supremely helpful review of the Urban Arrow nearly exactly 3 years ago. I was wondering whether you had gotten the chance to try the Urban Arrow, whether the 4th generation had come out since or if the UA was still the bike to beat, whether any alternatives to the UA were now there to be considered.
    I write from the point of view of someone looking for a car alternative for our urban lifestyle and the Urban Arrow still seems to me to be the one to beat but was wondering whether, from your more knowledgeable standpoint, that was still the case.
    thanks again for the article. Really great breakdown…especiallly given you’d never actually seen/ridden the bike!