A problem has emerged with the Segway Human Transporter, the US$5,000 high-technology scooter that has computerized gyroscopes to keep it from falling over.
It falls over, at least under some conditions.
The Consumer Product Safety Commission and Segway LLC announced a recall on Friday of all 6,000 Segways, which, the announcement said, tend to tip forward when the batteries are low and the rider does something that requires a quick burst of power, like speeding up abruptly or trying to bump over an obstacle.
A user who has such an accident must first ignore a number of signals from the Segway to get to the hazardous tipping point. The machines have a prominent battery level indicator built into the handlebars, and as power drains below a certain level, a light comes on, an alarm sounds, and the handlebars vibrate. A Segway can be charged at any power outlet with a cord that is identical to those used in most personal computers.
Doug Field, chief operating officer for Segway, said the company had undertaken the recall to make a safe product even safer. "If there's anything we can do, we want to do it," he said.
The company, based in Manchester, New Hampshire, has so far received three reports of riders falling. The recalled machines, the company said, will get a software upgrade that will cause them to give their battery warnings earlier and to shut down before low power levels become a problem.
The Segway was introduced last November with great fanfare and with coverage by a largely enthusiastic press corps. For the most part, the glow has persisted despite slow sales. Last month the television news anchor Dan Rather said the vehicle "just might be the most revolutionary leap since the automobile."
Among other things, the Segway has been hailed as a way to ease urban traffic congestion and to conserve energy. But it has also been derided as a yuppie toy, and there was nearly gleeful coverage of a spill that President George W. Bush took while on one.
That machine was not turned on. When standing on one that is, the rider feels as if it is intuiting his balance and stance, and compensating for them -- which it is. But as with so many modern wonders, that ability requires battery power, and the company said machines with too little juice could not work their magic.
Even before its debut, the Segway drew much attention, because it was cloaked in secrecy. Since its introduction, the company has hired an army of lobbyists in an effort to get state and local governments to change laws that bar motorized vehicles from sidewalks.
The Segway is best approached after a bit of training. It has two wheels, one on either side of its base. Once the user is accustomed to the feel of it, riding is remarkably intuitive: Leaning forward causes it to move forward, and pulling back on the handlebars slows it down.
Ken Giles, a spokesman for the product safety commission, said the company brought a Segway to the commission's offices during discussion of the recall, and "a bunch of us rode it around a conference room."
"It's a fascinating machine," he said.