Jolly interesting development

[andyh2]

2 speed hub motor on the way....

News: SRAM Launches E-Bike Drive System at Taichung Bike Week

Hope the power output is more 'normal' than the SPARC system. Not available until late 2012 by the sound of it though.

 

[kitchenman]

Interesting indeed. I would like to "stokemonkey" it. I'll add it to my list of motors to try.

 

[Eaglerider]

Does this mean a manually changed motor final drive ratio or will it be automatic. I would imagine this will give hub drives more ability on steep hill climbing, which would be fun!

I want one already!

 

[Miles]

See also: Endless-sphere.com • View topic - SRAM to launch e-bike hub

 

[Miles]

Going back in time to an idea I proposed, following a line of thought that flecc initiated:
http://www.pedelecs.co.uk/forum/electric-bicycles/654-light-fastest-climbs-mountains-pretty-efficient-6.html#post8998

 

[flecc]

Yes, I remember suggesting years ago that a hub motor with two automatic gears was possible, even using something similar to the existing planetary gear system. I hope SRAM have cracked it, they seriously intend going places against Shimano at long last now, with a whole new range of gear hubs due shortly.

 

[flecc]

This may be condemned to remain a single gear bike system, so primarily one of interest to utility cyclists and of less interest for the more keen cyclist. For most the motor system will be the more dominant power source overall.

It obviously takes up the entire width of the rear frame opening with it's single rear sprocket, and I'd guess that probably is one of the standard splined gear hub mounting sprockets. If so, using a multi-sprocket freewheel with the frame widened will be ruled out.

A solution to providing some alternative rider gears would be to use a triple chainwheel set, since the frame used is a standard bike one.