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SRAM Launches E-Bike Drive System at Taichung Bike Week

8 12007 Sales & Trends

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SCHWEINFURT, Germany – There’s something very special appearing on the horizon of the e-bike market. It’s SRAM’s drive system for electric bicycles. The SRAM E2 Electric-Assist System is launched today at the start of the Taichung Bike Week in Taiwan. It’s unlike anything available yet and is developed around two main focus points: simplicity and drive-ability.

SRAM disclosed the most interesting features of its e-bike drive system to OEM’s earlier this year at Eurobike. At Taichung Bike Week which is being held this week, the complete system has been introduced to numerous product managers for their MY 2013 line-ups.

“No me-too product,” was according to SRAM CEO Stan Day the first established focus point when the e-bike project started. “Other than that we said that we wanted to be right from the start the best in class. And with our background in internal as well as external drive systems for bicycles I am convinced that we can be just that. With that in mind we studied the market and studied in particular on the question what OEMs are looking for with regards to e-bike components and what consumers want.”

These focus points have been turned by SRAM into an ‘integrated’ e-bike drive system that consists of a very limited number of parts. As simplicity safes big on assembly-time, the component maker set out to limit the number of parts of its system and all the goes with it when taking into account that the battery, motor, controller, display all have to communicate through wiring with each other.

With regard to the other focus point - drive-ability - the SRAM drive system functions automatically and with that does what the component maker set out to do; making a system suitable for people used to cars and other modern products that present a sophisticated human interface.

For that SRAM incorporates an rear wheel e-bike hub motor which is special, very special indeed. That’s because it integrates the motor, an automatically shifting 2-speed gear system; a torque sensor as well as the motor controller. The built-in torque sensor measures chain movement as well as frame-flex and is a patented system.

The automatically shifting 2-speed gear system is not SRAM’s new Automatix hub. The e-bike hub shifts automatically between two motor speeds but it uses a different gear system.  Also, the shift point is adjustable on the Automatix hub, but it is not adjustable on the e-bike hub. Furthermore, the e-bike hub is built on a single-speed drivetrain (1 chainring, 1 cog) and even though the torque output shifts, the effective gear ratio is always the same, and it is whatever gear ratio that the bike is set up with (42 – 17, 44 – 17, etc.).

These focus points have been turned by SRAM into an e-bike drive system that consists of only 2 parts and one cable. There’s the motor,  the battery and the cable that connects the two. An easy to install system to be used in standard IHG frames.

SRAM emphasizes that its e-bike drive system doesn’t need special requirements; there’s only the wiring that goes from the rear wheel hub motor to the battery. And that battery has an on/off button with which the whole system is operated. No handlebar display and cable that needs to be fitted for it.

 

by Jack Oortwijn

8 comments

  • # 1

    Francis

    Brilliant concept. Can't to test ride the eBike from this motor
  • # 2

    Efried

    There is an additional reinforcement visible on the rear frame. Could be that the internal gear creates higher torque and thus more stress.
    Also some experience from riding the beast would be appreciated. What is the lag between start of the manual braking and the stopping of the propulsion?
  • # 3

    Take

    Only v-brake on rearwheel possible? Mmmmm
  • # 4

    Keith

    eBikes just won't take off until they fix the terrible design due to bulky batteries. Sort the battery, incorporate it into the frame, and then we have a winner. check out Johnny Loco for great eBike design (non comment on functionality as I haven't tried).
  • # 5

    Gary

    The motor and controller technology seems to be innovative but you are going backwards with the battery style and placement.......very ugly. I agree with Take above, need to incorporate the battery into the frame.
  • # 6

    Piter

    Yes indeed...the battery-package is very ugly...battery inside the frame is much more sweet..:-) Sparta had this for years and bikes looked great! But SRAM is not a bicyclemaker but makes parts for bikes...So it will be easier for them to sell this concept. Perhaps they can on special request design batteries for build inside the frame...
  • # 7

    Jim

    Stan's comment "no me too product" is slightly off. It's going to be a "no one wants product". According to those that previewed it, underpowered and overpriced are the words used to describe it.
  • # 8

    Mike

    Sticking the battery in the frame is a great NO NO.
    Batteries have to be replaced every 2-3 years and there are already legions of older bikes whose owners are having trouble getting replacements

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