F/S Build

Looking for input converting a bike i picked up

Bike
Steel frame & swingarm 5" travel


Plan
Rear hub motor 48v, ~12t geared, Can build a wheel could piece together from different vendors.
Battery 13-15ah, 3c+ no lipo
Controller 20-25a

Questions
Am i underbuilding anything?
Recommend battery/controller/motor?
prefer stateside for shipping. total under $1200
thanks

I assume you're getting a MAC 12T kit from em3ev since you mention "12 T"... Personally I'd jump to a 12 FET 40A controller for the 15% hills. I also think you could get away with a 10T (what I run) as it climbs hills like a champ. I'm not a lightweight either (sitting at about 200b).

This is me on a 12% incline on dirt but with a 29er (larger diameter wheels). You'll get more torque with a smaller wheel.
[youtube]pn9OPYqDvtA[/youtube]

As for batteries... If you get the kit from em3ev, you might as well get the battery from there as a kit. Plug and play. I personally run lipo with a BMS for power/weight/size ratio. I'm stocky at 5'10 and have short legs, so I can only fit on a 16" frame bike (size small... so I really don't have room for much in the frame triangle). I'm jealous of you tall dudes who can get large bikes =(.

When selecting batteries, make sure it can push out at least 5C so you don't stress the pack.

Looks good your goanna need to replace your rear spring with a heaver one, I have the 10t mac works great you will like it

thanks for the help

Map your route in mapmyride or any other elevation chart so you can actually see the real elevation to make sure it's actually 20%. (which is quite steep).

The correlation for amps and volts is : More volts = higher speed. More amps = more pushing force. If the road is flat, you wont need much pushing force (so 20A will be fine). If your path is hilly then you want more amps to power up them. That said, a 40A controller is 40A peak, so it "can" do 40A but if the ride is flat, it will only provide what is needed (say 20A) depending on your throttle control (your brain and hand). Better to have more than Less. Yes its harder on cheaper batteries but if you get quality batteries it should be fine.

thank you

Another mount option. Total weight 48lbs

I think you should support the frame bag underneath in some way. Otherwise, the straps will start to tear away.

Got the new battery wired up

Cooks up hills pretty good at 48v+
Just under a grand for all the electrics
Controller, tools, pump & waterbottle fit in the bag.
thanks for the help