Newbie Seeking Advice For First E-Bike Build

i have a trek 3500d and real happy with it. with the smart pie you should get 20+ mile range real easy with a 20 amp battery
personally i would get 48v 10ah battery. the little bit of extra money is well worth it. mine does 24 mph on the flatsat 48v and the 36v you will get around 18mph
the triangle on the 3500d is kinda small and most batteries will not fit. at least the golden motor battery will not. what you plan to order will be all you need. any questions just ask. here is a link to my 3500 disk build with the magic pie http://motorbicycling.com/showthread.php?p=401020#post401020 and here it is with the smart pie http://motorbicycling.com/showthread.php?t=41915

With a smart pie and that battery I would expect 35-40 mile range.

I have only built a couple electrics and recently was looking at the hub motor kit you choose for a new trike build and once again went against going hub motor.

The max speed you will ever get is the max RPM the hub will turn at maximum power draw and it just goes down from there due to terrain, battery power left, and even a stiff head wind.

I am a die hard fan of the mechanical advantage you get with gears in the drive train be it gas or electric power so like my current personal ride I am going center mount attached to the pedal drive train to take advantage of the bikes gearing.



Here is a better shot of the meat and potatoes.



The key parts are the two freewheel sprockets, one on the motor, and one inside the Bottom Brackets pedal crank assembly.

If you just want to pedal without motor power the motors sprocket freewheels with no drag, if you just want motor power the pedals freewheel so you feet don't have to keep up, or you can use both at the same time all with the rear gears.

Granted my Caddy with a NuVinci CVT hub is a little over the top the principle is the same and the package will even fit on a tiny bike like this 7-speed Trek I build for 'height challenged' woman hehehe ;-}



Both can top 25MPH on flat ground yet still maintain 20 even up hill or with a head wind with a little pedal help.

Just food for thought from a guy that builds gas MB's for living and has high performance gas bikes always at hand yet prefers my Electric Caddy for my little local runs.

For reference this kits 37V 960W LiFePo battery sucks for range but everything else has been great and nothing bigger battery won't fix.



I really shouldn't mention this but my Caddy build with all new parts was under $1200 including that new Cadillac NuVinci shifting internal hub bicycle.
Don't expect to get out that cheap but even at $1500 including a good internal hub shifting geared bike to me simply can't beat as far as what you can get from electrics as in my experience they need it the most.

On a side note I am motorizing a 7-speed Kent trike right now the same way ;-}