Retrofit an electric drive system on any bike with bimoz
The electric bike conversion market is about to see a new entry in the form of a mid-drive unit from a company that just raised close to $1 million in crowdfunding.
There are two basic approaches to products in the growing electric bike market, one of which is to build them from the ground up as dedicated e-bikes, and the other is to offer conversion kits which allow riders to repurpose their existing bike with an add-on electric drive system. There are valid arguments on both sides, as purpose-built electric bikes are said to be better able to handle the additional torque and stresses that electric drive systems put on the frames and components, while the kits that enable conversion of a conventional bicycle into an electric bike allows cyclists to use the bikes they already own and ride as the starting point. In addition, when it comes to the price of a purpose-built electric bike, e-bike conversion kit enthusiasts tout their lower costs, but that's not always the case, as a new system from Switzerland's bimoz illustrates.
Last year, a crowdfunding campaign from bimoz raised almost $1 million from backers, and is looking to start shipping its $900 (pre-order price) electric bike drive system in the next few months. At the full MSRP of $1,669, the 250W bimoz system doesn't exactly seem like a deal, but according to the company, it's the "world’s lightest and smartest" e-drive, with a total weight of just 2 kilograms (4.4 lb) and an estimated range per charge of 150 kilometers (93 miles), so its value may match its price for some riders.
Instead of being an all-in-one drop-in system that puts the motor in either the front or rear wheel, as some companies have been doing, the bimoz setup is a mid-drive system that "can be installed with little effort on any bicycle."
The 44V lithium ion battery pack, which is available as either a 110 Wh or 290 Wh configuration, attaches to the seat tube, where it feeds electricity to the 250W electric motor mounted on the bottom bracket on the opposite side from the chainring, enabling a top speed of 25 kph (15.5 mph).
A mid-drive system like the bimoz can be used with virtually any gearing system, whether that's a singlespeed or a derailleur-based drivetrain, and that feature is said to make the most efficient use of the torque from the motor by driving the chainring, as opposed to a hub-based motor, which drives the wheel directly. This isn't the only mid-drive conversion on the market, but the bimoz appears to differ drastically from most, if not all, of the other options in that it avoids the addition of an external motor module that sits out in front of the bottom bracket. The bimoz e-drive system is instead attached to the bottom bracket on the left-hand side, where it adds a bit of width between the crank arms (and appears to replace the left one), in an installation process that is said to only take about 20 minutes to complete.
bimoz ran its successful Indiegogo campaign last year, and is close to shipping out the first units to backers, but it appears as if pre-orders can still be made for the units. For a single unit and the smaller battery, the cost is still listed as $899, or $999 with the larger battery, and shipping is included. More info is available at the company website.