Dahon's generally won't accept a normal front hub motor as the dropout spacing is only around 79 mm, and most front hub motors are 100mm. However, there is one small hub motor (nominal 500watt?) that I have - the Crystalyte 209, which drops into a Dahon nicely - it is designed for folders. I have mine on a Speed 21 Dahon. It is a brushless direct drive hub motor and has quite high RPM per volt so it can get your bike to well over 20mph. The torque of the motor is reasonable, but not "high". It can get warm with 1000 watts sustained into it. I'm running it with a sensorless controller from bmsbattery.com. It was easy to fit the bike. You can get them from itselectric.ca (in Calgary, Alberta). The "normal" hubs like the Crystalyte 40x or 50x series, or Nine-Continent or GoldenMotor wont fit in the front fork. I wanted to preserve my rear 3x7 Sachs gearing so I went for a front motor solution. It works well. The 209 weighs around 8 or nine pounds as I recall. The 206 is even faster, I wouldn't use that motor. Apologies awdnut, I didn't see your note on the 209.