I don't ride it hard. Most of the time on a good road surface at 18-20 mph. I have had it to 30 mph a few times but just for a short time. So far, zero problems.
Pushing a bike 5 mile is not much fun I'm sure. sorry that happened.
Yes, as Mike said " Subaru Robin EHO35 motor". Not the most powerful but they have held up very well for me and I have two other bikes with the same motor. As also mentioned, It is a Stanton drive. This is my first time to purchase one of his drive kits and not disapointed at all. I have tried just about every system offered to motorize a bicycle and this is one of the best. I do not commute on a bike as many on this forum seem to so my experince is more limited, it is mainly a hobby.
The reduction gears are heavy duty and look to be made of good qualty metal. I can hear gear noise as I ride along but it is not very loud. The gear case is machined very nice. The case comes in two haves and is bolted together with allen head bolts and no gasket. High quality gear lube is put in the case and no leakes at all even without a gasket. That seems to me, some pretty good machine work. A small short chain is run from a sprocket at the gear reduction case to a sprocket on the wheel. With the auto clutch and this neat set up, all I have had to do is start it up, pull the throttle lever and away I go. No tinkering to keep it operating right. I have a fairly large remote gas tank that allows me to ride all day with out fueling. Hope I was not too detailed.
Thanks Mike for the warning about the fenders. I still would like to keep them on for awhile and probably change them out later, but will keep a close check for any cracking.