Electric motors and gears.

[hoppy]

We sometimes discuss the pros and cons of using variable gear ratios in the drivetrain of our electric bikes. I've noticed that all the electric cars on the market so far have a single fixed gear ratio. Electric motors give most torque but least efficiency from zero rpm and most power and efficiency at much greater rpm. The greatest weakness of electric propulsion seems to be limited range so it might seem worthwhile to maximise efficiency and range with variable gear ratios. Interestingly the new Formula E electric car racing series (starting on ITV4 at 8am on Saturday) uses cars with 5 speed gear boxes.

 

[Geebee]

It's one of my pet peeves with electric cars.
A local gentleman converted a Daihatsu mira and fitted an Lynch 11kw motor with the gearbox still fitted and it can climb any of the hills (steep) and can cruise at 110 kph (from memory top speed 130 kph) on the highway, I forget the range but it was impressive for a small pack.

I think some of the issue is everyone wanting 1 second 0 to 100 kph in their commuting vehicles.

 

[tongxinpete]

The Chinese company Shenzen Unite (who also make many bike & trike motors) do a two speed rear transaxle for small cars,I have seen it somewhere on Alibaba