The kit I got is frame mounted and chain driven with a dry plate (automotive style) clutch. There's no pull starter and the only drag on the driveline with the clutch disengaged is from the chain and two extra cogs, which isn't enough to wear a person out, though it might slow them down about 1 mph. You can see it at
That'sDax.com.
Similar kits have reportedly gone over 40 mph with minor modifications. Today on the way to work, I kept it around 15-20 most of the way for break-in. It feels like it will pull me to just over 30 mph or so on the flats which is really plenty for me - and twice the legal speed limit for a 'motor assisted bicycle' in the state of Oregon. :P
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