If you look at the left motor casing of the Red Empulse E1 you will notice it is a black casing. Now if you zoom in and look through the rear wheel spokes of the Red E1 to the black E1 behind it you will notice that there appears to be a gold motor casing.
This may just show that the black casing has not yet been installed. But even if that is the case I have an E1 and an R with me now. And the gold inner casing only appears to be on the R. You can see the same uncovered gold casing on the R if you look through the rear wheel spokes on the Black E1.
Not sure if this points to anything. It may mean nothing. But the E1 with me now also has a red spring on it (which is apparently changing to black) so perhaps there are some exciting modifications ahead.