I have to 650B conversions (an 80's Takara Medalist road bike and a KHS John Howard Turbo roadie). I'm running a 1 x 7 on the Takara (friction bar end shifter) and 1 x 8 speed on the "Turbo Dog." Takara drive train: Newish Deore. Turbo: Deore RX from the parts bin. The Turbo currently has a single DT shifter, but I'm planning on putting an indexed or friction bar end... as soon as I can find one or find someone who wants to trade for one. The Takara is my Oct - March commuter (I live in Wisconsin). I'm running a 44 Tooth Biopace up front (it's what was hanging around) and I never seem to drop the chain. The Turbo is a new conversion but after a couple busy weeks of biking, I"ve had zero issues with chain drop. I'm running a DIY chain guard on it. For city riding I love the 1 x 8. Just less cabling, less levers, less is better. Go for it. What have you got to lose? Take off the hardware, run it... don't like it? Put the stuff back on.

Picture of the Turbo


picture of the DIY Chain Guard (52Tooth chain ring, ground on grinder wheel, smoothed out on wire grinder wheel)