I have a Dahon MU P8 conversion bought from CH White & Son. This looks to use the specialbikes kit at
www.specialbikes.at - Tandems. If you were to buy the kit and fit it yourself, I would guess it would be cheaper than the nano, sparc etc. However, the MU does need some modification to the frame to take the controller. This is done by CH White and results in the controller being mounted quite low on the frame.
Disadvantages are that the motor may be underpowered for some at 180 watts & 24v (depending where you live and what you wan to use the bike for). Also, the CH White configuration is throttle only. The specialbikes kit uses NIMH batteries which again may be an advantage or disadvantage depending on your point of view but does slightly add to the weight.
One real advantage is the motor has minimal drag and the bike can be ridden as a normal bike with no problem.
I have had the bike for about 6 weeks and use it for some leisure riding and commuting to & from work - approx 6 miles each way. It is fine for this & overall I am very pleased with it. Even in very heavy rain there hasn't been any problems and the only setback so far was a puncture the second time I took it out. There is an earlier thread about the MU P8 and other conversions from 2 or 3 weeks ago.
Hope this helps.
