SAN FRANCISCO -- Electrobike calls it the world's fastest hair dryer, but its Pi electric bicycle isn't even in the same league. It has half the wattage of a Conair -- just 750 watts, or about 1 horsepower.

That's the federally mandated limit for an electric bicycle like the Pi, which does triple duty: It's a traditional pedal pusher, a motor-driven bike and an art piece. You can ride it as long as your legs and lungs hold out. Or just nudge the throttle with your thumb and let the 36-volt pack of nickel metal hydride batteries do the heavy breathing. Or you can park it in the living room between your Eames chairs and Albero sofa and admire its arching architecture.

Electric bikes: A review of the Electrobike Pi in the Sept. 26 Highway 1 section incorrectly stated it could be ridden on bike paths. Though electric bicycles are allowed in bike lanes attached to roadways, they are not allowed on equestrian, hiking or recreational trails, according to the California Vehicle Code. —

One look at it, and you know: Pi occupies a rarefied space in the world of two wheels. It isn't just the heady Euclidean name, Ayn Randian design or ultra-green cradle-to-cradle engineering that makes it so unique. It's also where it's sold.

Pi isn't available at bicycle, scooter or motorcycle shops. Beginning next month, it'll be for sale exclusively through Design Within Reach, a nationwide 65-store chain that offers super-stylish furniture and accessories at supposedly affordable prices. With its midcentury modern profile and $7,500 price tag, Pi fits the bill.

I had the chance to test a preproduction version of Electrobike's ridable sculpture on its home turf of San Francisco. In the morning I spent with the bike, I found it to be more aesthetic than athletic, but overall, it was an impressive machine.

At 58 pounds, it was light enough that I could lift it off the pavement with my bare hands. Although it's significantly heavier than a regular bicycle, that wasn't an issue unless I was turning fast and hard. The bike's batteries are stuffed into Pi's elegantly curved backbone, which means the bulk of their weight is centered but carried high -- not so heavy or high that they made the bike flop, but enough that I was aware of their presence.

In a straight line, that was irrelevant, especially when Pi is powered by the motor. Pi operates in three modes -- pedal only, motor only and motor assist, which combines the two. I found myself riding mostly in the motor-assist mode, because my legs are in no shape to spin up San Francisco's Sisyphean hills on their own.

The motor kicked in when I pressed the throttle with my left thumb. Twisting the right handgrip, I was able to adjust the continuously variable planetary transmission to handle different grades of hills or flat pavement. Made by NuVinci, in Oklahoma, the transmission integrates the motor and pedals into a single driveline so it can easily pull itself up a hill, while the flywheel not only produces electric energy but also regenerates it when braking, so the energy's released again when it's spinning.

Pi's maximum speed is 20 mph stock, but with a little after-market hot rodding, i.e., a larger chain ring and gears, the bike is capable of about 46 mph.

Making those upgrades does change Pi's California Department of Motor Vehicles classification, however. Ramping up its ability to reach higher speeds makes it no longer legally recognized as a bicycle. Instead, it becomes classified as a moped (if modified to go up to 30 mph) or motor-driven cycle (if it goes any faster). Both levels of speed modification require motorcycle (instead of bicycle) tires, headlights, turn signals, a speedometer and a huge amount of hassle for riders who, to be on the up and up with the government, want a clean conscience along with their faster wheels.

On a single charge, which takes about 2 1/2 hours plugged in to a standard outlet, Pi has a range of 25 miles. Add an extra-range battery to its underbelly for an additional $750, and you've bought yourself another 25 miles. That's in motor-only mode. Pedal, and you can go as far as your hamstrings let you.

Even though Pi has a motor, it's legally recognized as a bicycle. That means it can go anywhere a regular bike can go -- bike paths, bike lanes, even public transit.

No license or registration is required to ride an electric bicycle, although you do need to be at least 16 in California; a bicycle helmet is also required, though Electrobike, apparently anticipating that some riders will modify its bikes to go faster, suggests a Department of Transportation-approved motorcycle helmet may be more appropriate. The company also backs that suggestion with a free helmet coupon for each Pi sold. Fashionistas rejoice: It's a high-end designer model from Laura Smith.

The helmet is one of four items included in Pi's steep price. Electrobike also kicks in a luggage rack, a pair of panniers and three saddles. Why three? Because there are several different spots where you can attach a seat to the plumped backbone, thus accommodating a broader range of body types. Riders just need to be between 5 feet tall and 6 feet, 2 inches. Anyone who doesn't fit within those parameters can buy a custom frame.

Pi is assembled in California. All but two of its 20 component manufacturers are based in-state -- an effort to factor the environmental costs of manufacturing into its clean and green equation. Electrobike claims that fewer than 200 pounds of carbon dioxide are created in the manufacture of its Pi -- 60% from the mining, transport and smelting of its aluminum monocoque frame and 40% in the manufacture of its 26-inch bicycle tires, battery pack, motor and other components.

That footprint is so faint as to be ghostly when compared to that of a midsize car, which creates thousands of pounds of carbon-dioxide emissions in its manufacture and, according to the EPA, an additional 20 pounds per gallon burned while driving.

Riding Pi creates zero emissions, whether it's pedal-operated or motor driven. It's charging the bike that creates its main carbon footprint, to the tune of about 210 pounds per year for a rider who uses it to travel 100 miles per week with motor power. Use the bike's accordion-esque solar charger accessory, and that number can be cut in half. The solar charger costs an extra $1,800 and, presuming the sun is shining, takes eight hours to fully charge. The battery pack is good for 400 charges before it needs to be replaced. While nickel metal hydride batteries are recyclable and significantly less toxic than lead-acid and nickel-cadmium batteries, replacing them isn't exactly cheap. A new pack is a lot more than a Duracell -- $750.

Electrobike is making 500 of its Pi model. All of them are painted the same Ferrari red and will be sold through Design Within Reach. But Electrobike has three similarly shaped models available through its website: The pedal-free Pi-e, the three-wheeled Pi 3 and a gas-electric hybrid motorcycle called Pi X.

You know. So riders can have their Pi and eat it too.

2007 Electrobike Pi

Base price: $7,500

Price, as tested: Brushless DC motor, 36-volt nickel metal hydride battery pack, 11 amp-hour capacity, 750 watts, continuously variable planetary transmission

Maximum speed: 20 mph

Maximum range: 25 miles per charge (motor-only mode)

Seat height: 29-36 inches (depending on saddle position)

Weight: 58 pounds