Doesn't the RadRover use a freewheel? So in order to go with a 12 speed cassette, you would need a different wheel...meaning a different motor. On top of that, you could not use any 12 speed, because the high-spec ones require a special freehub body, and I am not sure you could put one of those on a hub motor. Sunrace and possibly another manufacturer makes a 12 speed cassette that fits onto a Shimano compatible 8/9/10 speed freehub body, but it does not have the 9T/10T 12th and 11th gears, negating some of the advantage of going to 12 gears in the first place.
On SRAM systems, it is called the XD Driver, and on Shimano, it is the Micro Spline freehub body.
I misspoke about the 9T 12th gear; that is not common. 10T is the normal 12th position on SRAM and Shimano systems. Only e*thirteen makes a 9T high gear cassette.
Too bad the conversion can't be done. However, I'm mainly after a 46 or 50t gear to help with some of the longer or steeper climbs. If it's gotta be freewheel is there anyone who makes a freewheel with those cogs?
The largest freewheel that I am aware of is a 13-40T, but it is 8-speed. I do not know if there is clearance on a RadRover to accept an additional cog. I rather doubt it.
