Electrical Gear Shifting with CAN

BIKES Electrical gear shifting with CAN

Bosch e-Bike Systems has announced an electronic solution for integrated gear shifting. In future, the company’s drive system can be fitted with three gear-shifting variations for different requirements. CAN enables the data interchange between the components.

USERS OF E-BIKES CAN DECIDE whether they want their gears to shift automatically in line with their cadence (Nu-Vinci, technology from Fallbrook) or speed (Sram), or to select the ideal gear themselves with the electrical assistance of paddles and gear shifting recommendations (Shimano). These built-in gear shifting components promise comfortable pedelec cycling along with a higher level of safety and a harmonious overall design. The electronic solution will be launched in the market in Spring 2015 combined with the Active Line and Performance Line and the Intuvia on-board computer.

What the solutions have in common is that the components are not only supplied with electricity and operated electronically but that a genuine data interchange takes place via CAN. This data interchange enables coordinated and optimized gear shifting and shows the gear or cadence that is currently in use on the display. Bosch’s Intuvia is an operating computer that can be attached to the handlebar. It has a separate control unit, which is also attached to the handlebar and can be used without taking the hands of.

Nu-Vinci technology: cadence-based continuous and automatic gear shifting

The integrated Nu-Vinci technology is based on a predefined pedaling cadence preference. The H|-Sync gear system, connected to the e-bike system via the Bosch interface, adjusts the transmission automatically to the preferred cadence, both uphill and on the level. Even when cycling uphill the system adjusts the gearing automatically. Thanks to H|-Sync the pedaling cadence can be adjusted to between 30 and 80 revolutions per minute via the display and the Bosch Remote. The cyclist specifies gradually how intensively he or she wants to pedal. The seamless N360 hub ensures smooth gear shifting.

H|-Sync dispenses with the Nu-Vinci display. The advantage is that the user has all of the important information available at a glance on the display (gear and cadence screen). Alternatively, Cadence screen (Nu-Vinci) on Intuvia display (Photo: Bosch) manual gear shifting with defined settings is available as an option.

Shimano: integrated electric gear shifting

The built-in gear system is suitable for users who shift gears a lot and enjoy shifting gears and like or prefer shifting gears fast. The system is based on manually operated electronic gears in combination with the Japanese company’s Di2 Alfine-8 and Alfine-11 or Nexus-8 internal hub gears, all of which can be controlled electronically via a Di2 adapter and CAN. While shifting gear, the motor is throttled briefly, which makes the process gentler and smoother.

The Shimano controls have a sporting feel to them. Paddles enable the user to shift gear up or down swiftly. The gear that is in use is shown on the display. The system incorporates for the first time the Bosch gear recommendation, which helps to make better use of the battery’s power by means of an arrow on the on- board computer display. Cadence screen (Nu-Vinci) on Intuvia display (Photo: Bosch) The Di2 series cannot only be used in e-bikes: The Ultegra Di2 electronic shifting technology is employed in racing bikes, where it also makes shifting faster and smoother. An automated derailleur adjusts the tension of the bicycle chain continuously. The electricity is provided through a battery, but the different parts of the system communicate via CAN, same as in the e-bike system.

Sram – Speed-based gear shifting

The Sram Dual Drive 3 Pulse is also automatic, but based in this case on speed. The DD3 hub can be combined with a cassette (with up to ten sprockets) and shifts gear automatically in three stages, subject to the speed. Users can therefore enjoy the ride, including the acceleration, leaving the system to handle everything else. Even when starting, the right gear is always in place. This version does not require an extra control, the system functions on its own. Fewer components on the handlebars ensure an improved overview and a leaner appearance.

“A common feature of all three solutions is that they offer the user more comfort and safety by maintaining a constant cadence, by shifting gear automatically or by changing gear electronically fast and precisely,” says Tamara Winograd of Bosch e-Bike Systems. “Bikers always have a reliable system by their side that shifts into the right gear at traffic lights or cycling uphill. They can then concentrate fully on the traffic or the countryside and have everything under control at all times.” Fewer controls unclutter the handlebars, while the paddles make shifting gear both sporting and smooth. Cadence screen (Nu-Vinci) on Intuvia display (Photo: Bosch)