My Mxus 3K V3 Build

greg176 said:
Here is my e bike as it stands so far. It has a Mxus 3k 5t motor. I chose the 5t because I have some steep 15% hills to climb. The battery is 13s7p made of recycled Tesla cells from ES member Okashira. It has a S12SN 40 amp controller and LCD3 display from BMS Battery.


Nice build mate, welcome!
You live in a beautiful and remote spot! no need to worry about legal power limits out there :mrgreen:
 
The law here is 500 watts and 32 kph max for motor assisted cycle. They have a category for Limited Speed Motorcycle at 1500 watts and 72 kph but I don't think you can get that with a U Built bike. I need to get one of those 500 watt Big Chicken Motor stickers and that should cover it. That is also why I have stuck to using a mountain bike to keep it stealthy.
 
greg176 said:

13-14 gauge Sapim spokes with brass washers on Alex DM24 rim. Was going to drill hub but decided at last minute to use washers. I was surprised at how easy it was to build wheel. 300 Km on the bike now and spokes still good tension.

No Torque arms?
 

I tried a couple of torque arms and none fit so well. The side stand had a hole which fit the axle exactly so I threw a clamp on it. I torqued the axle nuts to 50 ft-lbs and with an approximate motor torque of 50 ft-lbs I feel safe. This bike is kind of temporary as I am watching Craigslist for something better. Can't decide between an A-Line or a Felt cruiser. It may be that whichever shows up for a good price first wins.
The motor is definitely overkill but with such a hilly island I liked how this motor can run so cool. Who knows I may just go to 72 volts as well. I went on the bike without a motor and with a GPS decided what would be best max speed.I came up with 40 Kph and so 48 volts. Riding it now for a couple of months I'm beginning to think it would be safer to go faster so fewer cars pass on these narrow roads.
 
I put a GT Power meter between the controller and battery today and made a few runs up and down the hill to see regen braking amps. First two runs with LCD3 set to 1 I got 30 amps max regen. I tried dialing it down with the LCD3 set to 3 and I got 39 amps max regen. Like I said in another post you really have to hang on when hitting that button. I'm a little worried that this kind of amps could damage the battery 13s7p Tesla cells from Okashira. If you assume NCR18650B 3200mah at .5c 1.6 amps times 7 = 11.2 amps max.
The s12sn contoller has two brake inputs. A yellow 5v and black ground the button closes those for braking. The other plug has those two wires and a red 5v. I tried a hall throttle on that to no effect. I now assume that it is set up for a 5k ohm throttle. They a little bit too expensive to buy just for a test. May try a 5k pot there first.
 
Major development. After months of watching Craigslist i managed to buy a 2003 Norco VPS Shore. It has a Manitou Travis front fork and is in overall good shape. Paid 350 CAD that's 260 USD right now. It is a 19" frame with a 24" rear and 26" front tire. It would be nice to go with 24" tires but I may run it with the 26" wheels for now.
Norco.jpg
 
Cool frame! love the old VPS's!
Does the geometery feel weird on flat ground with the 24 in the rear?
 
No. It feels fine except for the seat angle. I'm trying to decide on what size wheels to run. It is a bit tall for me and best would be to switch to 17" motorcycle tires and rims but that adds up to a lot of money. I most likely will run it with the 26" tires I have now. An expensive learning curve with these bikes.
 
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