Sounds like max motor RPM is lower? That SMRE motor must have been a screamer, if this motor maxes at 8000 RPM ..
Thanks for the update. Now we can put the SMRE / Parker discussions to bed : )
Not quite yet... I know how you like to dig and calculate, so let me provide the real "back story" so as to prevent any future misinformation (albeit well-intentioned).
The Empulse R (Brammo designed, Parker manufactured in New Ulm, MN) motor is an internal permanent magnet motor (IPM) and part of the "GVM" family of magnetics design for traction/vehicle applications (like the race bike motor). It makes peak power around 4500 rpm, but has good "continuous power" out to 8000 rpm. This gives it a very broad and useable power band for use on the road - leading to comments about being able to use the bike at a wide range of speeds in a single gear without shifting.
However, just because you CAN run it to 8k rpm, doesn't mean you should if you want to maximize efficiency and power. 5-6k rpm on this motor is a pretty good range to operate at to maximize efficiency.
SMRE does not manufacture electric motors, so there is no such thing as an SMRE motor. There have always been motor partners involved in the development of the IET. The "other" motor we use has the same peak power, just at a different rpm and with different power curve past peak power. I wouldn't call it a "screamer" - just a motor with slightly different operating characteristics. Both solutions are great
motors and a great fit for the Empulse. The Parker has the edge in peak torque and continuous power rating owing to a very good cooling design. This has made it the motor of choice for the higher priced, higher spec Empulse R.
Regarding the question about sprockets, we now run a 38T on the rear of the Empulse R. All of the bikes used by the press for their review and tested at dealers were built with an earlier revision of the motor, and slightly different rear gearing. The customer bikes have the benefit of about +4hp on the top end, and taller rear gearing for substantially better off-the-line performance. Just another example of Brammo overdelivering (better late than never)...