I became interested in motor assisted bikes about a year ago.
Golden Eagle Bike Engines had the best concept for motorizing a pedal bicycle.
The reason for this sentiment is the "Happy Time" motor. These motors and kits that surround them come from an engine designed in Russia in the mid '40s and maybe were popular there until the '60s. The Engine was then cloned by the Chinese for there domestic transportation needs and later imported to America under various vendors but all the engines are basically from Chinese factories. There quality is notoriously poor and with there mid frame mount on cheap bicycle frames are at least to me some what problematic! They all have chain drives to the rear of the wheel and the kits and bikes very much resemble small motor cycles.
All of these engines would be illegal in Wisconsin where I live. We have a 49cc restriction and a speed limit of 30mph or less in our state. All reasonable restrictions.
The problem as I see it is engine displacement and all of the problems with that and a human powered bicycle especially the cheap bikes from places like Walmart.
The best cyclists such as Lance Armstrong can generate 500 watts for about an hour in events like the time trial in the Tour De France. The bikes like Lance rides are designed to take the rigors of super strong pro athletes like lance Armstrong. A strong pro rider could simply tear apart a cheap Walmart bike in just a few rides. My point with all this is simple. My Robin/Subaru EHO 35 is rated at about 1200 watts plus the power I can muster as a really fit cyclist of maybe 300 watts with the average untrained cyclist able to muster maybe 150 watts. My point here with this is simple. Once you add a motor you place a lot of stress on a bicycle frame that it was not designed for and risk that frame set failing with catastrophic results!
I believe that these oversised HT engines are simply to much for the common bicycle and that there are serious safety concerns with these cheap kits!
I also believe that the best engine mount on a traditional pedal bike should be a rear rack mount such as what I use. With the frame mount model all of those stresses are added to the frame which it was not designed to handle. GEBE proves to me how well there system integrates with cheap Walmart bikes since many of their customers use the kits on these bikes with little problems. They have hundreds of testimonials about their product on their website! I think that there is something to their belt drive system mounted via a rack on the rear of the bicycle that is gentle to the bicycle as long as one power assists the bicycle.
So, in a nut shell I have become really opposed to these cheap Chinese Happy Time motors. I believe in personal freedom and personal responsibility.
Kevin