Greetings all,

My first post on Bike Forums so here goes ... Have been riding road bikes most of my life and now in my later years find my self in need of some assistance on those longer rides. Thought adding a small electric hub motor to my bike would be a great idea. Decided not to mess with my beloved CAAD9 alum/carbon fork road bike so I bought a good used vintage Specialized steel MTB for the project instead.

The bike will be used here in south Florida on level roads with some inclined inner-coastal bridges for rides of 30 to 40 miles. I would like components that would give me 15 to 20 mph with me supplying constant medium to hard (hard for the bridges) pedal assist. I'm 125 lbs. - bike is currently 28 lbs. Will be purchasing a rear geared hub motor and lacing it up myself into a 26" rim. Plan on using a V3 Cycle Analyst to manage everything.

Questions:

After reading this great post from chas58 (4/25/13, "Q100 Stealth Builds -") I've pretty much decided on this motor from BMS ... Q100H, 36 Volt, 350W, 260 rpm, 12.6 ratio. BMS describes this as a high torque version of the Q100 with the same dimensions. BMS recommends this controller for it. It's described as a "Torque Simulation Sine Wave Controller" which is different from a regular controller. Does anyone have any thoughts, opinions, or suggestions for a different controller or motor? I'm really set on a rear drive sub 6 lb. motor, with what ever controller that works and is reliable, again will be using Grin's V3 computer to manage everything.

As for a battery, I like the 38120S Headway LiFePO4 3.2V, 10Ah cylindrical cells. A 12s pack gives me 38.4V (nom.) 10Ah, 3C discharge rate. Fewer cells to make a pack and a much greater cycle life ... the 9lb wt. and pricing may not be as good as a lighter premium 18650 pack but it still seems like a good choice to me. I really like the concept of screw terminals on these cells as opposed to the spot welding on 18650 cells. I realize the 38.4V at 10Ah only gives me a 384whr pack but I will be drawing less than the 3C rate of 30 amps ... hopefully a lot less. So does that mean I can expect an increase in the watt hours of this pack?

The total price for the (12) 38120S cells, BMS, cell holders, buss bars, assembly kit (wires, terminals, anderson connectors, (2) 6" x 6" Lexan sheets and shipping ( $31.12 ) is $417.12 from this supplier . Not sure if their BMS will work with my small motor. Any thoughts on these batteries and BMS ?

I loaded all this data into Grin's motor simulator . Used the outrider std. (300rpm unloaded) hub motor rated at 250 to 500 watts (closest I could find to the Q100H motor) and using the 38.4V pack. At 75% throttle, 0% grade, and no pedaling, the graph showed 15mph with a range of 30 miles. Electrical data box showed motor pulling 7 amps, battery supplying 188 watts at 5 amps with .4V voltage sag. Putting in about 90 watts of pedaling effort I'm up to 18mph with range up to 355 miles. Motor now pulling 700ma (.7A) with battery supplying 19 watts at 500ma with no voltage sag. I wonder if Grin's simulator factors in wind resistance? Am I missing something here?... almost sounds to good to be true. Anyone used this simulator before?

Trying to nail down all the details before I make any purchases has been a daunting task for me, think I'm pretty close now thanks to this forum and other great websites.

Would greatly appreciate any suggestions or thoughts you folks might be willing to share. Especially as to trusted sources for these specific components. Thanks very much!