I doubt that it needs the weight and complication of a gearbox. Just more robust bearings in the upper unit of the Ace Redrive, it may need a bit beefier belt as well. Guessing it would increase weight up to around 5 kilos (11lbs) or perhaps a bit more. This one fits VW so maybe it will handle the torque but whether it will handle the Increase RPM needs to be asked. https://www.airdromeaeroplanes.com/reductiondrive.html Or build your own.