Well, I received and installed the 14-34t rear freewheel yesterday. I rode the bike to work today and here's my results.
Pros: When I select the 28t front sprocket and the 34t rear sprocket, I have much more low end torque. This equals getting up to speed quicker and a better ability to climb hills. I was able to keep the bike up to 13mph up a hill that normally slows me down to 7mph and... the motor/controller did not cut out when in this configuration. The pickup from 0-15 is amazing and, I'm at 19mph b4 I know it.
Cons: With 28t front/34t rear selected, 20-21 is my max speed (I believe due to rpm limitations of the motor). The next cog below 34t is 24t. This is too large of a step down for the motor and it has a hard time gaining any more speed on the flat or slight upgrade. I was only able to reach 22, or better, on a downgrade but, I was able to reach 25 on a slight downgrade (crouched position). The motor/controller did cut out twice this morning when in the 28t front/24t rear configuration.
Thoughts/Observations: I believe I need a "custom" freewheel. My thoughts are 34/30/26/22/18/14/11t. Going from 34t to 24t is just too big of a jump for the small 24V/500W motor to handle at once. If I could slowly step down the R/R, it would be more beneficial and easier for the motor to handle. It would also provide a smoother transition of motor torque to the drive sprocket.
I would also benefit from switching to a 26/36/4xt front sprocket for initial speed bursts but, I'm going to hold off on that for now. I believe that 22/32/42 would give me even more low end torque/pickup but I'm not sure how necessary that is. I know that I've never used the 48t front sprocket (ever) and I rarely use the 38t front sprocket.
Plan of action: I'm going to attempt to take the old freewheel (11-28t) and the new freewheel apart and create a custom freewheel as close to the ideal one mentioned above. It will probably be something like 34/28/24/20/16/14/11t. Is this possible to do?? The old one is a SunTour 11-28t and the new one is a Shimano 14-34t. If not, what are my other options (or do I have any)? My strategy is to make one change at a time, evaluate the results and decide whether to keep that change or where to make a new one (using the process improvement procedures proved by the Japanese automakers of the 80's and still in use today). It seems when you solve one problem, it always causes a new one.
Other news: I saw a 36v/1000W motor on Ebay (Currie motor). I am in communication w/ the seller to try to get the motor and controller. I also saw
this motor and it looks pretty tempting too. Does anyone have any experience with that motor?