Posts Tagged: economics

Jun 2010
by don

Cargo bike economics: maintenance

Today I took my bike for its first checkup after 7 months and over 500 miles of hill-chewing.  As you may recall, I have done no maintenance on this bike other than one application of chain lubricant.  Since I rely on it to provide safe transportation for my family, I wanted to ensure that no latent problems were developing.

For the diagnosis, I went to one of Seattle’s pricier bike shops.  I deliberately chose a different shop than the one that built my bike, because I wanted a second opinion — especially on those mission-critical brakes.  The owner of this shop is a big fan of the Big Dummy/Stoke Monkey bike, and I thought it would be enlightening to talk with someone who is somewhat skeptical of my bike.  He has a reputation for pulling no punches, so I prepared myself for some rough sledding.

But actually, things went quite well.  The owner found several occasions to point out advantages of the Stoke Monkey, but these were arguments that I’ve written about previously.  He complained that the BionX hub motor makes it harder to adjust the rear disc brake calipers, because the hub blocks easy access to the dial that positions the brake pads.  He charged me an extra $10 for the additional effort required.

The total bill was $75 for labor.  He adjusted and lubed my derailleur to recover my lost gears, cleaned and tuned the brakes, and lubricated various cables.  I paid another $25 to upgrade the front brake cable for better responsiveness, but that wasn’t critical.  Using the $75 figure for essential maintenance, I calculate a cost of about 15 cents per mile.  On the one hand, this figure is probably high due to the difficult geography this bike has to tackle.  On the other hand, it’s probably too low on an annualized basis, because I didn’t have to replace any parts this time.  In another 6 months, I may have to replace at least one of the disc brake rotors and possibly the pads, but that shouldn’t cost more than $50.  As I suspected, the regenerative braking of the BionX motor seems to be extending the life of my brake components.  What isn’t clear is how often other components will need to be replaced, and how much that will cost.  Although it will be pretty cheap compared to repairs/maintenance of a car, the number of bike miles will also be less, so it remains to be seen which is cheaper on a per-mile basis.

Just to be complete, the electricity to help propel me during this time period averaged about 1/2 cent per mile.  Hardly worth mentioning compared to the maintenance.

One sweet moment occurred while I was paying my bill: a customer was admiring my bike and asking questions about it.  He was initially attracted by those huge Xtracycle-incompatible pannier bags.  He was really intrigued when I told him the bike was assisted by a quiet (and virtually invisible) electric motor.  He was standing less than a yard away from the owner’s Big Dummy at the time, but it was my bike that caught his eye.  I have no doubt that the owner had him converted to a Big Dummy shortly after I left the shop, but my bike and I had our moment.

I plan to return to the same shop after another 7 months and 500 miles.  The owner did a good job and seemed to know what he was doing.

May 2010
by don

Cargo bike economics, part 2

In my last post, I wrote about a few of the implications of riding my electric cargo bike from a financial and social point of view.  Today I’ll tackle another topic that I’ve been pondering: how much extra time do my cargo bike errands cost?

My first errand under the stopwatch was picking my kids up after school.  As sometimes happens, I was late leaving our house, so I had to literally sprint the half mile up the hill to the school.  When I pulled into the parking lot, I was surprised to see that I had done it in 2 minutes!  Sure, I had cranked those pedals pretty hard, but you can keep up a pretty good effort for an interval that short.  While it’s true that I could get there a little faster in a car (possibly even a minute faster), I would spend much longer waiting to get through the traffic jam in the parking lot, so the bike wins this contest easily.

For my next errand, I needed to pick up a few items for dinner from the closest grocery store.  The route winds through neighborhood streets for 1.7 miles, descending about 500 feet.  The bicycle route tool in Google Maps says it should take about 8 minutes; it actually took me 9 (I got stuck at a red light for a long time).  I spent 11 minutes finding my groceries in the store, and then I pedaled back up the hill in 9 minutes (no significant traffic light delays in this direction).  So, my total errand time was 29 minutes.

To compare, I jumped in our mini-van as soon as I got home so I could measure the same errand in the car with the same traffic conditions.  I got to the store in 6.5 minutes, and the return trip took 7.5 minutes.  The total errand time would have been 25 minutes.

Although the car would have saved me 4 minutes, this was really a best-case scenario for the car.  There was very little traffic at this time of day, and there were plenty of parking spots.  Many times I spend several minutes looking for a place to park.

To be fair, there are many errands in the 5 or 10 mile range where the car is much more efficient time-wise, especially if the route uses a freeway outside of rush hour.  If you’re thinking about buying a cargo bike, you will have to determine whether the kinds of errands you do make this feasible for you.

The terrain is also a factor.  Google estimates that my return trip from the grocery store should have taken more than twice the time it did.  Without the electric motor, the time and effort would force me back into the mini-van on many days.  I really can’t imagine using this bike without some kind of assistance on these hills.