So we started traveling the Prairie Path near our home and had great times, except when we hit a steep hill. My skinny-tire, 10-speed, road bike would literally spin its wheel on the crushed lime. So I went looking for a mountain bike. I bought a Schwinn Impact - 23" frame - big, wide, 2.20, heavy-lug tires. Basically a tractor.
It pulled the trailer like a dream. I loved that bike. We put many miles on that rig, biking through other towns along the Prairie Path, stopping at their playgrounds, watching the fountain in our town, lunching at our favorite hot dog stand or picnicing in a park.
Since the Burley was enclosed, Kari could take her stuffed animals with her and I didn't have to worry about her ejecting them along the way. There were places to keep drinks and snacks, her blanket, our picnic lunch, all the good stuff. We had great times for several years, until she outgrew the trailer.
Eventually our second daughter also outgrew the trailer and I hung it up in the back porch around 1999. The hooks are about 15 feet off the floor in the back stairwell.
In the early 2000s, I started riding my bike less and less as Post Polio Syndrome robbed my legs of strength and endurance. Around 2004 I stopped riding altogether and put the bike in storage. A sad day. I began driving the car for everything, even the 8 blocks to band practice.
Then in the summer of 2008, $4.50/gal gas prices pushed many people back to their bikes to save some money. The news media made a big deal about it. I didn't have that option. But mid-summer I had a brain storm. I remembered the electric bike conversions I'd seen over the decades (most of them pretty crude engineering) and I wondered if modern technology had made the idea more viable. The motors and batteries of the past made for pretty lame conversions, but I knew that battery technology, in particular, had advanced a lot in the last 10-15 years. So I put Google to work looking for ebike conversions.
Jackpot.
I found a company making what looks to be the most sophisticated system available. Check out Bionx. From an engineering standpoint, the hub motor is the best thing to come along in the electric bike world. All the older systems were clunky chain or belt or gear drives - none of them clean and simple like the new hub motors. There are several manufacturers of similar, direct-drive hub motors for bikes, but they all use simple, variable speed controllers that assume you will be either pedaling or running on motor alone. None of them (as far as I can tell from their web sites) are a dynamic, intellegent assist system that combines pedal and motor power without constant human control.
The Bionx computer controls the amount of power to the motor based on two things - your control settings and how hard you pedal. You set the amount of assist you want from 0 to 4 (0 - 35 - 75 - 150 - 300% assist), using the contol head. There's a strain gauge (torque sensor) in the hub which measures the amount of force you are applying with the pedals. The computer powers the motor to the degree your control setting calls for. The computer also varies the power to the motor to even out the combined pedal and motor power, compensating for different leg strength (a major issue in my case) and for the fall off of torque as pedals go through top and bottom dead center. The result is very smooth power to the wheel and minimum battery drain for a given speed.
When you first start pedaling, you're on your own. When your speed rises above 2 or 3 mph, the computer smoothly ramps up the battery assist. From there on, the assist is controlled to give you the speed you want (controlled by your pedaling cadence) with only as much boost as your controller setting calls for.
You also get regenerative braking which charges the battery, but it's pretty minimal unless you're riding down big, long hills.
Bionx' most popular model is the PL350. It uses a 350 Watt hub motor and a 36 V, 9.6 Ah Lithium-Ion-Manganese battery. The manganese version of the LI battery is better for high discharge current than the common cobalt-based LI used in cell phones and laptops. They claim a range of around 25 miles at the highest assist level (4) and as much as 60 miles at minimum assist. Of course this is with a new battery, flat ground and no wind. LI batteries under average use are good for only 2-3 years, 4 at best, so there are fairly serious battery costs long term. One can always hope the price of the battery will fall over the years - or even better batteries become available for the same price.
The battery and hub motor add 16 lbs to the weight of the bike. It's very noticable the first time you lift the rear wheel to swivel the bike around in tight quarters, but it's a small price to pay for a system that gets you back on the bike. And the older technology systems are even heavier for the same range, or much shorter range for the same weight. In fact, the Bionx system using the same motor but a NiMH battery adds 6 lbs but gives about 20% shorter range.
The Bionx is a pricey system. Very. And nobody's discounting it yet. It's about double the cost of most other, simpler systems using a manual controller and cheaper, heavier NiMH batteries. But it's a very well engineered kit that a mechanically competant bike owner can install. It will fit almost any bike - all common frames, brakes, deraileurs, etc. I didn't install the kit myself as the shop offered to do the install for only $60. I couldn't turn it down.
I didn't buy the Bionx to save money on gas. I'd have to do a LOT of riding (over 8,000 miles) to make back my cost even at $4 per gallon. I won't be riding it places I would have driven the car other than an occasional trip to the grocery store. I bought it so I could ride again. To get outdoors more, get some sunshine and see some trees, whatever. That's worth a great price.
