In December 2019, Germany’s Dr. Dennis Freiburg, mechanical engineer, stamped his identify into the Guinness Ebook of World Information with the world’s lightest ebike: the 6.872-kg (15.15-lb) Freicycle. Now, he is revealed how he did it – with a 600-watt friction drive motor.
The Freicycle began out as a 2016-model Merida Scultura – a carbon-framed climbing racer with a sub-1kg (2.2-lb) body and rim-mounted brakes to chop down on weight as a lot as attainable. Freiburg took issues up a notch with a full carbon crank and 3D-printed pedals, and barely-there carbon rims. Each steel half was assessed to see if it may very well be changed by one thing lighter and 3D printed, and the brake calipers have been one instance of one thing that was tossed for a lighter, 3D-printed design.
The motor and battery sometimes add a whole lot of weight to an ebike construct, and right here Freiburg acquired a little bit inventive. As a substitute of a hub or mid-mounted drive motor, he took the small motor powering the primary rotor of a mannequin helicopter and original it right into a friction drive that rests towards the rear wheel beneath energy, and swings out of the way in which when it isn’t in use.
The motor is software-restricted to an EU-legal 250 W and 25-km/h (15.5-mph) most pedal help pace, however when unlocked it will probably ship as a lot as 600 W and push the bike to speeds as much as 48 km/h (30 mph). Even in restricted mode, the Freicycle’s ludicrously low weight makes it a lot simpler to journey quick in an unassisted trend than most ebikes, and the tiny motor provides no pedal drag when it isn’t touching the wheel.
To hold the Guinness-mandated minimal 137-Wh battery, Freiburg grabbed a light-weight, off-the shelf drink bottle, crammed it up with batteries and management electronics, made a 3D-printed bottle holder, and wired the entire thing as much as that. He 3D printed a brand new lid for the bottle that is additionally able to appearing as an on/off change for the bike and an help stage dial as properly. Light-weight sensors within the crank and wheel present the system with info on the wheel pace and pedal cadence.
The complete drive system weighs lower than 2 kg (4.4 lb), and the battery is enough for a variety between 19-35 km (12-22 mi). Freiburg says it isn’t an excessive amount of of a ache to hold an additional drink bottle battery pack if he wants a little bit additional vary.
The bike is simply 72 g (2.54 oz) over the 6.8-kg (15-lb) minimal weight required by the UCI group for worldwide race occasions – though there are a good few folks pushing to have that minimum weight lowered or eliminated.
The challenge as an entire value someplace round €20,000 (US$23,790) to appreciate, which is so much for a motorbike, however not so much for a Guinness World Report. For those who’re on the lookout for the lightest ebike you’ll be able to truly purchase, the lightest we are able to discover is the 11-kg (24.3-lb) Invisitron R1, which rocks a 250-W motor and prices AU$3,300 (US$2,380) – and that is a a lot simpler price ticket to return at.
See the Freicycle in motion within the video under:
LIGHTEST E BIKE within the WORLD Showreel – Guinness World Report