SRAM DD3 Pulse E-Bike Shifting System

J.R.

Well-Known Member
NIJKERK, the Netherlands – SRAM recently launched the DD3 Pulse e-bike shifting system. This new shifting system is fully integrated.

Depending on speed, the gear hub automatically selects one of three gears: whether braking for a traffic light or going up a steep hill. In addition to the automatic wide ratio 3-speed gear system the rider can shift manually anytime. The automatic three-speed-shifting is fast and low-maintenance and well integrated with the electric motor.


Photo: SRAM DD3 Pulse e-bike shifting system. – Photo SRAM
 

stevenast

Well-Known Member
NIJKERK, the Netherlands – SRAM recently launched the DD3 Pulse e-bike shifting system. This new shifting system is fully integrated.

Depending on speed, the gear hub automatically selects one of three gears: whether braking for a traffic light or going up a steep hill. In addition to the automatic wide ratio 3-speed gear system the rider can shift manually anytime. The automatic three-speed-shifting is fast and low-maintenance and well integrated with the electric motor.


Photo: SRAM DD3 Pulse e-bike shifting system. – Photo SRAM

Sounds cool. Can you explain to a non technical person, like me, why a three-speed system has nine cogs?

You said they can also shift manually at any time ... is it two different systems?
 

Cameron Newland

Well-Known Member
Sounds cool. Can you explain to a non technical person, like me, why a three-speed system has nine cogs?

You said they can also shift manually at any time ... is it two different systems?

It's a 3-speed, a 9-speed, and technically a 27-speed. Yes, they're two different systems. The only gears that the rider can select are from the 9 external gears on the rear cog. The 3 internal gears are selected electronically depending on speed. That means that you might get some strange behavior, including unexpected shifts or the dreaded phenomenon known as "gear hunting", with this system.

Haibike already offers something like this on their US ebikes. (Haibike XDURO Trekking Pro).

A funny story: I test-drove a Haibike with the 3 internal gears (SRAM Dual Drive) paired with an external cogset/derailleur at Motostrano, just south of San Francisco last month. A few weeks later, I went in to EBIKELANE, which is Motostrano's sister shop in San Francisco, and mentioned to them that I had ridden a Haibike with such a unique transmission, and John from EBIKELANE didn't believe that such a system even existed, even though I had ridden it at his sister shop!
 

J.R.

Well-Known Member
Just found out that if you get a 2016 Bosch e-system with the SRAM DD3 Pulse, you can manually switch gears on the internal three gears. Looks like it's a feature that is exclusive to the 2016 Bosch eShift:

http://overvolted.com/2016-bosch-ebike-product-updates/
You seem to be really up on this system! I really like the idea of more gears and this system is perfect for mid-drives. I don't need 21/24/27/30 gears, but want higher highs and lower lows than my current 8 speed Sram and this 3 by system is a great way to achieve that.
 
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