I found the following thread and didn't see any real complaints with these 36V motors, but I still am leaning towards a 48V motor:
http://endless-sphere.com/forums/viewtopic.php?f=3&t=27905
After reading through a lot of these threads I'm starting to think about building my own bike. I am an engineer by trade, and have the technical ability and know-how to put together my own bike and select the components, but I was kind of looking forward to getting started riding right away, as well as having a 2-year waranty where I could take the bike to the local dealer if I had any problems. However, there seems to be a big jump in price between the 36V and 48V commercial bikes, and at those 48V bike prices I'm starting to lean towards a DIY solution.
I am looking at this kit:
https://www.yescomusa.com/Brushless_Electric_Bicycle_Engine-_48v_1000w_Rear_Wheel_Hub_Motor_Kit.html
As well as one of these batteries:
http://www.pingbattery.com/servlet/the-12/48V-15AH-V2.5-LiFePO4/Detail
http://www.pingbattery.com/servlet/the-2/lifepo4-lithium-ion-phosphate/Detail
If I go DIY, I will most likely try to build a battery enclosure that I can put above the crank to help with balance. I really don't like how Prodeco and other companies put the battery over the rear wheel. I also have a Topeak removeable pannier bag that locks in place on my Topeak rack, which I would be unable to use with a battery over the rear wheel.
I'm also looking for a reasonable 26" bike to use for this project, preferably with disc brakes and front suspension, as well as a more upright position since I will be using this bike mostly as a commuter.
I found this bike, but it's priced ($490) more than I'd like to spend and doesn't have disc brakes, although I like the upright riding position:
http://www.giant-bicycles.com/en-us/bikes/model/sedona.dx/11509/55863/
I'm adding up the costs right now, and if I can put together a good 48V setup that is below $1500 (price of the 36V Phantom X2) then I'll probably go that route. I seem to be talking myself out of buying a commercial bike.
I'm going to search reviews on the YescomUSA 48V/1000W kits to see if anyone mentions uphill performance. Anyone with 48V/1000W setups feel free to chime in with your uphill experience.
After seeing this video of a HPC 1800W bike, I'm concerned that even a 48V/1000W setup won't be enough to get a big guy like me carrying gear up hills like in this video. The incline this guy is going up is very similar to the hills I will need to climb on my commute, and the hills on my commute are much longer. With my bum knee, I need to be able to depend on the bike to get me up these hills without pedalling.
http://www.youtube.com/watch?v=WWx5l34u2SE
I'm fine with going slow up the hills on motor only, even if my top speed is 5-10mph. On the flats I'm fine with 20-25mph top speed. I just want a dependable ride that will get me to work and back, which is about 24 miles round trip. I can charge the battery in my office at work, but I'd like enough capacity to make the round trip without charging, in case I forget to charge or something else comes up. I understand that uphill drains the battery a lot faster as well, which is why I'm leaning towards the 20Ah battery.
