Two Speeds, Two Chains

 Most of you, I suspect, ride or have ridden a bike with two chainrings.  I would imagine, however, that none of you have ridden a bicycle with two chains that isn’t a tandem.

Some folks are about to have that experience. They’re not Grand Tour riders or triathletes; none (as far as I know, anyway) plan on embarking upon a cross-country or round-the-world tour.

Rather, they are folks who use their bicycles as taxis, pickup trucks and cargo vans. I encountered such riders in Cambodia and Laos and even rode bicycles like the ones they use.  Those bikes, however, didn’t have the unique feature I mentioned at the beginning of this post.

So why, you ask, are some people about to ride a bike with two chains? And, where are they?

I’ll answer the second question first:  Africa.  I’ve never been there, but I imagine that parts of it are like the Southeast Asian countryside I saw:  unpaved roads and paths with few, if any bike shops.  And the shops that exist can’t order a part you need for your SRAM Red 13 speed shifter and have it delivered by Fed Ex the next day.

In such an environment, a bike that would need such a part would be all but useless.  And it would be worse than impractical for hauling a 15 liter metal jug of milk from farm to village.

World Bicycle Relief has been working to address people’s needs in rural Africa and other parts of the world.  It developed the Buffalo bicycle: a “tank” with wide tires, steel rims and a coaster brake. This was believed to be the bike with lowest possible maintenance. Also, because the bike has a coaster brake, it can be ridden with wheels that are significantly out-of true.  Oh, and it has a rear rack that can support up to 200 pounds.

As you can imagine, the bike is heavy. But its users didn’t mind:  Reliability is more important to them. That weight, however, combined with its coaster brake hub—which has only one gear—meant that most people couldn’t ride it up a hill, especially if it was loaded.

A new version of the Buffalo bike is designed to deal with that problem.  So why two chains?, you might ask.

Well, each chain runs on one of the two chainwheels—and one of the two sprockets on the rear.  Those sprockets are part of a freewheel that looks like a wider version of the ones found on BMX bikes. One chain wraps around the smaller sprocket and chainwheel while the other winds around the larger sprocket and chainring.

This arrangement results in a two-speed bike without a derailleur, internally-geared hub or coaster brake. So how does the bike “shift?”

Well, the freewheel contains a mechanism that disengages one gear while the other is being used. So, if you are pedaling in one gear, the chain still spins on the other.  And the “shift” is made by pedaling backwards, just as you would on a coaster brake.

Achieving that, of course, meant giving up that coaster brake.  Instead, a pair of dual pivot brakes binds on robust alloy rims to stop or slow down. As the developers explain, some strength may be sacrificed but, apparently, there’s still enough to support a 200 pound load in addition to the rider. And it’s also easier to true an alloy rim.

Oh, and everything on the bike—including the freewheel mechanism—can be fixed with a tool that looks like an oversized version of the old Raleigh spanner—or an adjustable wrench.

I, for one, would be interested to try such a bike, if for no other reason than to experience the two-speed, two-chain system.  And I am always happy when a practical bike—whatever that means for a particular place or kind of user—is designed.

Riding The Buffalo

 Bicycle enthusiasts—whether we sprint to finish lines, cross cities or continents or simply appreciate technology and fine workmanship—are ripples in the ocean of the bicycle world.

That fact is easy to miss or ignore if you live in a Western/Global North city with bike lanes and well-stocked shops, or if you do all of your bike-related shopping online. It didn’t become real to me until I went for a ride in the Cambodian countryside with a native and both of us rode bikes like the ones people in the area ride.

People who haul their stuff and themselves—I’m not talking about someone in Williamsburg or Portland picking up artisanal bread at the local farmers’ market—don’t ride the latest high-tech carbon fiber wheels and frames with 12- (13?)-speed electronic shifting systems. For one thing, they can’t afford such things.  For another, in the Global South—especially in rural areas—there isn’t a shop stocked with the necessary parts, equipped with the required tools and staffed by mechanics trained to use them—or any bike shop at all. And two- or three-day shipping isn’t available in those areas, even if the shop or an individual has internet access and can order.

Moreover, roads tend to be less developed and maintained, if they exist at all. A laden bike might be ridden on a trail or even on parched or sodden earth.

Bikes lead hard lives under such conditions.  Therefore, reliability and simplicity are the paramount qualities.

World Bicycle Relief—an organization I’ve mentioned in previous posts—understands as much.  In response, they’ve developed the Buffalo Bike, consisting of a rugged steel frame and a coaster brake.

In addition, WBR has trained over 3000 mechanics to keep those bikes rolling, mainly in Africa and South America.  Trek has partnered with WBR to ensure distribution and repair of those bikes.

According to WBR, it takes $165 to provide one of those bikes and keep it rolling.  That is less than what most department store bikes sell for in North America or Europe, and Buffalo Bikes are sturdier and require less maintenance.