Fridge on a bike trailer

Bike Trailers vs. longtail bikes

Christiania cargo bike
Christiania cargo bike

There are many alternatives to haul cargo on bikes – a fact that was demonstrated daily on the streets of Copenhagen during the year we lived there.  By far the most popular were Christiania bikes, which were used to haul various daily goods including kids and girlfriends.  There were also quite a few bikes with extended front ends, which look a bit awkward but have the advantage of keeping your cargo in view.

With such a variety of hauling solutions, the one cargo bike I never saw in Denmark is the one I’ve focused on in this blog: the longtail bike.  One might wonder why I haven’t broadened my scope a little.

The main reason is my readership.  Although my blog is read in many countries, roughly 80% of my readers are in the United States and Canada.  Since I’m most familiar with the transportation landscape in North America, I can offer suggestions and opinions that are appropriate here.  My experiences in Denmark strengthen my conviction that transportation must be tailored to local circumstances.

There are three things that make a Christiania bike a better choice for Denmark than the U.S.: flat geography, advanced biking infrastructure, and higher expectations or education about bikes in general.

As I’ve often said, flat terrain is a huge advantage for Danish bikers.  The Christiania bike is heavy and not very aerodynamic.  I rode one once and it required some effort to push it through a stiff Danish headwind.  I’m not sure I could pedal one up a Seattle hill, even without a load.

The bike infrastructure in Copenhagen enables a diverse ecosystem of bikes.  For example, many bike lanes in Copenhagen are wide enough for one Christiania bike to pass another without impinging on car lanes.  Contrast that with my own city, where some bike lanes aren’t wide enough to accommodate a single Christiania-sized bike.

Finally, these kinds of bikes are viable because Danes use their bikes differently than Americans do.  They tend to ride relatively short distances at a relaxed pace.  They are accustomed to seeing all kinds of citizens on bikes, including many senior citizens who are more comfortable on a tricycle than walking.  Bikes of many shapes and sizes are optimized for diverse needs.  Here’s a video that illustrates what I mean. Check out the guy carrying 4 kids, a kid’s bike, and a whole bunch of other stuff on his bike:

Bike trailers

Bike trailers represent another cargo hauling strategy that I rarely saw in Denmark.  I’m guessing that’s because the added length, the extra wheels, and the location of the cargo farther behind you make a trailer difficult to maneuver in cozy urban settings.  But I’ve been getting occasional emails from readers wondering about towing a trailer with an electric bike, so perhaps it is time to tackle the subject.

Before I start, I should say that I have never used a trailer, and I’m in the precarious position of expressing opinions that aren’t based on actual experience.  I’m hoping that my trailer-towing readers (I know there are some of you out there!) will let me know if I say anything stupid.

From a price standpoint, a trailer-based cargo bike has some advantages.  If you already own a bike, you can buy a nice trailer for about $500.  If you were to add an electric motor and lithium-manganese battery for less than $1000, your outlay would be at least $800 less than the least expensive electric longtail bike I’ve described in previous blog posts.  So how do they compare on features?

The trailer gets points for flexibility.  When you’re not carrying cargo, you can enjoy a nice electric bike that’s a little more nimble than a longtail.  It will fit on the rack of a suitably-equipped bus – not something most longtails can do.

Fridge on a bike trailer
Fridge on a bike trailer

The trailer can also carry heavier or awkward loads due to its longer cargo deck and lower center of gravity.  For example, here’s a story of a guy moving a refrigerator using a bike trailer.  That’s not going to happen on a longtail!

However, if you’re thinking of using your cargo bike for more common daily chores (carrying kids and/or groceries, for example), a trailer will be overkill.  It’s not going to be as easy to pack or to ride.

Everything I’ve said so far might be obvious, so the real question is how the electric motor is going to perform with a bike trailer.  Since it’s going to provide a significant boost to your leg power, the motor will

  • Decrease your effort
  • Increase your speed
  • Increase the amount of weight you can haul
  • Increase the slope of hills you can climb

The last 3 items on that list arouse some safety concerns.  Since the wheels of the bike trailer don’t have brakes, the momentum of your cargo will add stress to your bike’s brakes without adding weight to your wheels.  This increases the chance of skidding.  As I discovered here, a skidding front wheel radically diminishes steering control.  That would be a bad situation on a normal bike, but the bike trailer adds another complication.  Unless you’re stopping in a perfectly straight line, the trailer will impart a sideways force to your bike during hard braking.  I’ve seen enough jack-knifed trucks to be sure I don’t want to see a jack-knifed cargo bike.

What does this have to do with the electric motor?  Nothing, except that the extra power and speed provided by the motor will complicate emergency stops.  A hard stop at 25 m.p.h. is qualitatively different from the same stop at 15 m.p.h.  If my experience is any guide, it’s hard to resist the temptation to open up the throttle when there are no obstacles in sight.  Unfortunately, it’s the obstacles you don’t see that lead to emergency braking situations.

My gut feeling (again without practical experience) is that bike trailers excel at transporting big loads at moderate speeds over relatively flat terrain.  An electric motor would be helpful to get the load moving without shifting through all your gears.  Your safety sense must be your guide in determining how fast you allow that motor to propel you.

I have one other concern.  There’s a reason you don’t see a trailer hitch mounted on a Toyota Prius: the car’s drivetrain isn’t designed for it.  Likewise, most bike motors weren’t designed to tow heavy trailers.  Even if they work for awhile, the extra wear and tear may not be covered by the manufacturer’s warranty.  Anyway, it’s something you might investigate before pursuing this course.

If you use a bike trailer, and especially if you’re using a motor, I’d love to hear about your experiences.

  • Nice Post.

    I especially agree that heavily loaded trailers, when approaching and/or exceeding the weight of the rider/bike pulling the trailer you are risking a jack knife situation when braking from higher speeds or braking while overcoming downhill inertia. I have learned that lesson with personal experience. There are solutions however; a) stay on the flats b) ride really slowly c) add brakes to the trailer or d) carry the mass on the bike where the brakes are. My preference is d when carrying heavy cargo. Although when I bike tour with lighter cargo, a 2 wheeled trailer like the Burley Nomad is hard to beat.

    As for medium to heavy duty cargo bike comparisons-the American long tail vs the Euro front loader….the heavier the cargo the better a front loader performs with their lower center of gravity and centered mass. I especially like front loaders for navigating as you get to size up the road in front of you better. Long tails win at carrying things like kids and groceries at a lower cost and their easier learning curve.

    As for comparing front loaders, not all are the same. Although your time in Copenhagen confirmed the popularity of the traditional front loaders like the Danish Christiana or the Dutch Bakfiets, but the very modern Bullitt from Copenhagen is probably the most appropriate for the hillier cities we have here in the western US. An average Bullitt weighs in at 50-70 pounds (that’s 25-45 pounds lighter than the traditional front loaders) depending on cargo arrangement making them easier on the uphills. The most popular Bullitt here in Portland is the Shimano Alfine 8 speed internal hub equipped model with modern hydraulic disc brakes and a very efficient drivetrain making hills easier, safer, and less grueling. Carrying a kid and some groceries? a Bullitt is hard to beat when rolling around town….Very fun, stable, and zippy. And for those that live in the hills, a BionX PL 350 makes for an amazing hill climbing set-up on the Bullitt, and an easy installation on the optional external drivetrain models.

    Splendid Cycles

    • Don

      Thanks, Joel. It’s comforting to hear that my “informed speculation” about the pros and cons of bike trailers hasn’t strayed too far from reality. 🙂

      I agree that the Bullitt is a very attractive option for carrying cargo and turning heads. If I lived closer to a Bullitt dealer (there are 5 so far in the U.S.), it might have made for a difficult choice between the Hammer Truck and the Bullitt. However, because the Bullitt is a relatively expensive bike from a small European manufacturer, it will probably serve a niche of committed cargo bikers in the U.S. I’m guessing the number of BionX-assisted Bullitts in the world is surpassed by BionX-Hammer Trucks, and that’s a pretty tiny number as well.

      Despite my expectation that the Trek Transport+ will be the first electric cargo bike most Americans see, I hope that our market evolves like it has in Denmark, with a diverse set of bikes serving all kinds of needs and riders.

  • Dan

    I started with children’s trailers (Chariot single and double) seven years ago to haul my kids, added a Bikes at Work 8′ model a year ago when I was moving, and recently put a Surly Big Dummy (no assist yet) in the garage. I originally pulled the BAW trailer with an old Bianchi Axis, but now use the Big Dummy. One of the things that swayed me towards the Big Dummy, away from the Yuba Mundo and other cargo choices, was the ability to use the stock BAW hitch adapter. Surly spelled out on their website that the BAW hitch would work and I saw first hand that the Yuba would require a custom hitch design. I’ve moved a number of large/heavy items – fridge, washer and dryer, furniture, gardening stuff – with the BAW trailer and the Bianchi – on mostly level ground and under 2 miles. This weekend, I brought home four trees (10 gal) from a greenhouse 2.5 miles from home and with one substantial hill, using the Big Dummy. I had no problems, it was raining but I didn’t have to test my brakes in any sudden stops. Just taking out the Big Dummy on its own is convenient for most trips (I have the wideloaders for larger cargo) and easier to navigate on pathways, etc., but the trailer adds a lot of flexibility and ease of carrying items that are tall, long, or heavy. I’ve seen pictures of people carrying doors, washing machines, etc. on Big Dummys and Mundos and I’m glad I have a trailer for that sort of thing. The BAW trailer is very solid and well thought out (your picture is an older version, the new version uses lengths of extruded aluminum for the frame)and it is reasonably easy to adjust the length in 2′ increments. Another nice thing is that the two rear reflectors mounts are also drilled to accept a Planet Bike / PDW rear blinkie rack adapter. While I probably wouldn’t have bought a BAW trailer at the same time as getting the Big Dummy, having them both allows me to see how useful this combination is – providing a lot of cargo hauling ability and flexibility. The BAW trailer is also significantly less then the MSRP on the new Surly trailer. I would recommend people looking at some of the more cargo-oriented bikes to also consider this combination as an option that wouldn’t be much, or any, more expensive.

    • Don

      Wow, a Big Dummy with a trailer? That’s serious hauling capability! And interesting point about the hitch adapter. It hadn’t occurred to me that someone might want to pull a trailer with a longtail bike, but if you’ve already invested in good brakes and good hauling gears, it makes sense to leverage that rather than having another bike on hand to haul a trailer when that is required. Carrying a washing machine on a longtail is either showing off or asking for trouble!

      Thanks for sharing your trailer knowledge.