Pete has the coolest-looking SOZEV (Single-Occupant Zero-Carbon Emission Vehicle) in Seattle. (Click the photo to the right for a larger view.) It has turned a sweat-inducing, 45-minute slog up a killer hill into a comfortable 10-minute cruise. He rides to the Sounder commuter train station from his house and then from downtown to his office east of Seattle. Surfing the net while commuting by train is a concept that appeals to me. I wonder how well the free wi-fi concept is actually working out …
Pete said he would let me test-ride it, so I jumped at the chance and met him downtown. A hybrid bike’s top speed, like its weight, is not a very relevant indicator of overall performance. This one can go a lot faster than it should, but I suppose that’s true for every motorcycle and car in the world as well. The windscreen (which reminds me of the canopy on an F-16) makes it a little too aerodynamically clean, especially when going downhill.
Some bike seats can be, ah, “sucky for your sex organs,” but this one feels like you’re sitting in a BarcaLounger, and a laptop fits nicely behind it. If there were such things as protected bike lanes, we would all be riding rigs similar to this, replete with over-the-head fairings, turn signals, and electrically heated clothing. Entrepreneurs have not realized it yet, but with that much battery power, all kinds of things become feasible. Heated clothing could keep you warm and toasty in the coldest weather, negating the need to bundle up for the start of a ride and strip down toward the end of it. Turn signals would negate the need to take a hand off your brakes to signal (as cars race toward you from behind). With this much power, you can also light a bike up like a Christmas tree.
Engineering is the art of compromise. Recumbent bikes are favored for long, level rides with little car traffic. Their low drag coefficient really comes into play at higher speeds (drag is an exponential function of velocity). They also tend to be more comfortable because of the reclining position and seats. However, this low profile also makes them less visible, which can be a problem in heavy traffic. They are not so great on hills, but electric assist makes that issue irrelevant. Riding in Seattle with its heavy traffic, horrible roads, and steep hills may favor a conventional framed bike because they are more visible and nimble, although — obviously in my case — not visible or nimble enough. I was hit by a car on my way to test-ride this bike. I’ll tell you about it in another post.
Cost is another major variable. The “Coolest bike in Seattle” title comes with a price tag. The battery pack alone cost a grand. The bike is high-end and also cost a couple thousand. The well-engineered kit wasn’t cheap, either. On the other hand, when put in perspective, a $5,000 or $6,000 rig like this is not only a lot cheaper than a car, but also carbon neutral, and you can’t take a car on a commuter train.
For the nerds:
He waited several months for the battery to come in from China. Apparently the charger was delayed by UL certification. The pack has about the same overall dimensions as mine but stores twice the energy and therefore has twice the range. My DeWalt power tool batteries take up more space because they’re packed in damage-tolerant cases, each case has a potted circuit board, and each cell in a case is cylindrical in shape instead of rectangular.
I believe he said the cells are LiPo (lithium polymer) chemistry. If so, a single puncture or short circuit could make his bike look like a space shuttle launch. This is something he will need to watch out for. The batteries also take about six hours to charge (probably to prevent them from lighting off). The DeWalts charge in 30 to 60 minutes and won’t blow up.
Eco-Speed has been making kits for recumbents for some time now. Their website offers several battery options, including the stable LiFe (Lithium Iron chemistry). An obscure Chinese manufacturer selling LiFe battery packs wrapped in duct tape for unbelievably low prices has recently inundated eBay. They even come with a battery management system and chargers. Personally, I wouldn’t touch one of these packs with a 10-foot pole. Quality control has to be minimal to nonexistent, and the batteries may even be illegal copies of a patented design. You have to wonder what’s going on out there.
The powerful motor has cooling fins to dump heat and is protected by a 50-amp fuse. To put this into perspective, understand that a single 50-amp fuse also protects all four burners and the oven in a typical electric stove. This is why I traded amperage for voltage, although 72 volts can sting if you are not careful. The motor also ties into the gearing. That gearing combined with this bike’s small wheel diameter will race it up just about any hill it hits.