The Rubbee X, which claims to add 30 miles of sweat-free riding to any bike, weighs under 9 pounds and can be added or detached to a bike "in just one second."
While some companies are focusing on delivering a complete electric bike built from the ground up, which in many cases are being sold as a solution for older non-cyclists (or lapsed cyclists) to take some of the effort out of riding, others are looking to leverage the vast numbers of conventional bikes already in use by offering a drop-in conversion kit.
However, some of these drop-in e-bike conversion kits cost quite a bit of money, and can be more expensive than a complete e-bike, which keeps them out of reach of those on a tight budget. But in recent weeks, there have been a few affordable plug-and-play electric conversion kits hit the market, such as the Swytch, as well as a friction-drive option priced as low as $160. This looks to be a growing trend, as not everyone wants, or can afford, a brand new bicycle just to get an electric drivetrain.
Lithuania's Rubbee, which brought a previous iteration of its friction drive system to life via crowdfunding in 2013, is launching its latest model, the Rubbee X, with a Kickstarter campaign. This all-in-one unit is installed with a locking mechanism onto the rear of the seat post, where its mounting system allows it to be attached or detached quickly. The X has room for three batteries, which when used together are said to allow for a 30-mile riding range per charge, but it can also be used with a single battery installed for a lighter weight and a shorter riding range.
The Rubbee X weighs just 8.8 pounds with three lithium-ion batteries installed, and can deliver a 350W electric boost to the rear wheel, but the bike can also be ridden conventionally (without the device touching the wheel) until the electric drive is needed. A wireless cadence sensor allows for the electric drive system to respond to the rider's pedaling, a regenerative braking feature can add riding range, and a rear 'smart' brake light is intended to help with visibility. The charging time for the unit with all three batteries installed is said to be about 2.5 hours, and because the X is light and simple to detach, it's easy to secure and to charge.
Of course, because it's 2017, there's an app for the Rubbee X, which allows for selecting the level of pedal-assist, tracking rides, and collecting data about power output and regenerative braking statistics with its "advanced ride analytics."
Rubbee is currently running a successful Kickstarter campaign to launch the X, with backers at the £269 (US$355) level claiming the first units when they ship in June of 2018. More information is available at the Rubbee website.
Remember, crowdfunding projects can be risky, so buyer beware.
h/t New Atlas