EcoXPower by EcoXGear is another take on a concept which most Gizmag readers will be familiar with: harnessing the kinetic energy produced while one pedals a bicycle in order to convert it into electricity and charge a smartphone or similar device. Though we’ve covered several products of this nature in the past, such as Nokia's Bicycle Charger Kit, Dahon's BioLogic ReeCharge, and the PedalPower+, the EcoXPower sets itself apart by charging your smartphone or GPS and providing electricity to front and rear lights at the same time.
EcoXPower comprises two principle components: a handlebar-mounted, touchscreen-compatible and water-resistant case which will house iPhone, Android, Windows and Blackberry smartphones, MP3 devices and the majority of GPS models and, attached to the bike's front wheel hub, the main unit itself: a dynamo device that uses a clutch to engage the wheel's moving spokes and then convert kinetic energy into electricity. The two components are linked via a cable.
The main unit integrates a headlight and taillight into the casing, each of which are lit with LED's and controlled via a wired on/off remote switch located on the handlebars or, alternatively, a switch situated on the main unit itself.
EcoXPower's main unit packs a 700 mAh lithium-ion battery, which will power the lights and charger for up to 1.5 hours without pedaling, ensuring your lights won't falter when you stop for traffic. It measures roughly 6 x 3 x 3 inches (15 x 7 x 7 cm) and weighs 1.3 lbs (0.5 kg). The company states that its universal hub-mounting bracket will fit most standard and oversized wheel hubs, and it can be adjusted with an included Allen key.
The primary drawback of dynamo devices like the EcoXPower is that they can cause a significant hit to performance when cycling, and some products can make even a short ride feel like hard work. However, just how well the EcoXPower fares in this area won't be clear without a test ride.
The EcoXPower is available now from EcoXGear at a price of US$99.99.
Source: EcoXGear, via Engadget
I comes down to a choice between weight and wind resistance, and the drag of step-up gearing, unless you think that wearing through the sidewall of a tire like the old bottle generators did is a good idea.
There are alternatives other than sidewall-driven generators. Even decades ago, there were generators that mounted behind the bottom bracket. An even better alternative would be mounting a large diameter ring containing magnets on the spokes and a stator coil on the fork blade. No additional bearings or moving parts, completely maintenance-free, high tangential speed without gearing.
FYI, regenerative braking would be nearly worthless on a bicycle, whether pedal-driven or electric. It would take a large generator to create any significant deceleration force. Electric cars have motors big enough to do that. Seeing as how you seem to be worried about weight, lugging a few pounds of generator on a bike wouldn't be a good option.