Sram 2 speed

[Agreen]

In my state, a moped is defined as:

a cycle with pedals to permit propulsion by human power or without pedals and with a motor of not more than fifty cubic centimeters which produces not to exceed two brake horsepower and which is not capable of propelling the vehicle at a speed in excess of thirty miles an hour on level ground. If an internal combustion engine is used, the moped must have a power drive system that functions directly or automatically without clutching or shifting by the operator after the drive system is engaged."

So, it can shift, but it has to be automatic.

I've been reading up on the Sram 2 speed automatic hub, and found little information on their use on motorized bikes. A couple threads here and there, but it seems like nobody has ever used one successfully.

Upon further investigation, it seems that they shift way too early. Somewhere around 10 mph. I did find a tutorial on how to adjust it to around 15 mph, but I think it would be better around 20 or 25 on a MB. Here's the review:

http://mccraw.co.uk/sram-automatix-review/

So it looks like he bent the springs to make it engage faster. I was considering if I got one of these I could drill them out some?

But wait. Do you think it would even hold up against an engine? Seems very doable with a jackshaft, and it also looks very desirable since the police here seem pretty interested in me and my creations. A lot. And I'm not looking to make it faster, I just hate cruising at 9000 rpm.

 

[bowljoman]

Even if your bike shifts, its ok as long as it has a default gear. China girls come with a clutch already, dont ya know, and that runs contrary to some interpretations of the law.

I have a three speed and no clutch except for the main centrifugal one on the engine. So you can drive without having to clutch or 'shift', technically. Its arguable but moot because the vehicle does 45. However, because I can click into 3rd gear with my twist grip, I can lower the RPMs of the engine, and make significantly less noise at any speed. Id say its worth a try. my hub has held up for a long time.

 

[Agreen]

"once the drive system is engaged"

That's why the CG clutch is deemed OK. This one will be used with a jackshaft, so the power would go through the auto hub.

It would be pretty nice if I could gear it so that I could take off without pedaling, and cruise at a comfortable rpm still.