On Wed, 12 Jan 2011 12:29:40 +1300, Fred wrote:

How do the kits compare with purpose made bikes? Mounting battery looks
tricky. Like you I haven't found too much info.

Consumer ebikes are expensive and appear to be very limited in both speed
and style. Building your own has lots of advantages. You can choose the
style of bike you want (or already have) and you can get any style/size
motor you want for it. And the cost is a lot less. Most kits come with a
rear rack to mount the batteries in a saddle bag. I'd probably just use a
plastic box to put them in and secure it with bungee cords.

For a hub drive, I'd like to have a dual speed motor. One low speed high
torque and one high speed low torque.

They make a chain drive geared motor that let's you use the bike gears
(rear) also, but it's a little more expensive and requires changing the
chainring to a freewheel style. It's supposed to give better performance
than hub driven of same motor size but looks more difficult to install.