Romanian e-mobility startup Diodra is laying claim to making the world's lightest ebike with a bamboo frame. The S3 tips the scales at 15 kg (33 lb) and features an all-in-one hub drive that includes motor and battery.
Where many ebikes are built around an aluminum frame, some roll with magnesium alloy and others may boast carbon fiber, Diodra has opted for sustainable, lightweight and strong bamboo. The laminated bamboo has been bonded to an aluminum head tube, while an aluminum seat tube slices through the mid-section and ends in a bottom bracket.
The frame is weatherproofed with a "two component coating system" plus three layers of varnish, and the ebike's makers promise "exceptional vibration absorption, resulting in a remarkably comfortable ride unlike anything you've ever experienced."
Machined dropouts to the rear allow for adjustable chain tension and precision brake alignment. And the stylish aesthetic isn't spoiled by unwelcome cabling flapping about, as such things are routed internally to maintain clean lines.
The S3 is being made in Europe, which has restrictions on allowable continuous motor output for ebikes. This means that though the brushless rear-hub drive is rated for 500 watts, it has been restricted to 250 W. The company has informed us that the power cap will remain in place for US buyers at the moment, but will look into offering full power as an option. Stepped down or not, top pedal-assist speed beyond Europe's reach is locked to 32 km/h (20 mph).
A torque sensor is cooked in for a more natural, responsive feel to motor assistance over three levels, and electronic gear shifting has also been included for "seamlessly delivering the necessary power for various scenarios."
You may have noticed the lack of a battery on the gorgeous frame, and this is because the 300-Wh Li-ion battery is enclosed in the same housing as the hub motor. There isn't a throttle here either, and per-charge range is given as more than 100 km (62 miles) at the lowest power level.
Real-time monitoring and settings tweaking can be undertaken via a companion app running on a Bluetooth-paired smartphone, along with online problem diagnosis, navigation aids and "social features." Rounding out the key specs are 28-inch DT Swiss alloy wheels wrapped in puncture-proof Continental Contact Speed tires. Stopping power is provided by Shimano hydraulic disc brakes.
"The creation of the bikes was a complex and demanding journey that involved many years of research, development, and overcoming failures," said company founder, Sabin Dimian. "Honestly, I've lost count of the number of times we faced setbacks while striving to create a bike that is strong, lightweight, and low-maintenance. But in the end, we succeeded, and I'm incredibly proud that we never gave up. We developed these bikes to meet the needs of today's urban commuters."
The Diodra S3 is up for pre-order now starting at US$2,399. A non-ebike M8 version can also be had for a pre-launch price of $1,699, which rides with a Shimano Alfine 8-speed geared hub. Either way, an optional upgrade to a Gates Carbon belt drive is available, as well as optional accessories such as fenders and lights.
Source: Diodra
