The Enertia TTR powertrain seems like it's more similar to the Empulse than to the Enertia. Liquid-cooled motor (PERM 150W enertia TTR, PERM 156W empulse, PERM 120L enertia?), lithium ion batteries. With that in mind, I wonder what changes the Empulse RR has made over the Empulse - is it closer to the stock bike than the Enertia TTR vs Enertia is?