Urban Surfer UM70
Got my new board.
Used, but in good shape.
I am really liking the suspension, and carving of the board.
Definitely an upgrade over the G1 I have.
It is a lot heavier and sturdier though.
The wheels make a big difference, as I can go offroad now.
I will probably try to upgrade to lithium and a larger 600W motor.
Right now it is 24V 15AH Lead Acid, and 320 Watt motor.
I put in 2 DeWalt 28 Volt lithium batts.
It has about the same torque as the lead acids, but a lot lighter.
I'm waiting for a 1200 Watt 48Volt motor I bought off Ebay.
Hopefully the stock controller at 24 volts will work.
The motor can be used at 24, 36 and 48 volts
Put in the 1200 Watt 48 Volt motor.
It works fine.
The controller seems to be the limiting factor though.
It limits the speed.
Torque is still better now though, and better hill climbing.
I can go up about 20 degree hills now.
The stock controller is a 24 volt, 30 amp, 20.5 Volt cutoff.
The caps in in are 60volts though, so i should be able to overvolt it.
I am going to put a Watt's Up meter on the board, so I dont burn out my DeWalts.
I may upgrade the controller to 36 volts, and batts to 36 volt DeWalts.
Will post some pics when I have time.
The board is great, I went offroad, on gravel, grass, no probs.
Jumped a few small curbs and ran over some man holes.
Had some chain problems, but tightened up the slack, and it seems fine now.
The board does have some high speed wobble when going downhill un-powered.
If you power it or brake, that fixes the wobble.
I'm probably going to brake, it's too scary accelerating downhill too...
Wheel and new 1200 Watt motor
had to cut off some of the faceplate, and use expoxy to glue a metal mount to the motor.
Body of the UM70
2 Dewalt 28Volt in parallel, about 4.8 Ah, just enough for a bit of fun
The big cap says 60 volts and I think 100 uF
Most of the other components are all blacked out by some sealing compound and unreadable
The controller is 24 volts, 30 amps, 20.5Volts cutoff.
This is a picture of the controller taken apart
Capacitor is 60 volts
This is the fuse on the motor cylinder.
It is 30 Amp 250 Volts
There is also a fuse on the battery the same ,30 Amp 250 Volts
and a fuse on the controller, but I couldnt see the ratings.
I blew a smaller capacitor on the 24 volt controller.
My fault, I wanted to see if it would handle 54 volts, obviously not.
No big deal,as I had an extra 36 volt controller around.
I am now using a 36 volt contoller, and 4 Dewalt 36 Volt lithium Ion batts.
Torque is better, and board is lighter.
I can now go up probably 30 degree hills.
My main use of the board is powered uphill, and coasting downhill.
The power is like my ski lift.
My neighborhood is hilly, so I have lots of downhill runs to ride.
Lots of fun, this board is really stable once you get used to it.
The little bit of speed wobble, can be reduced by carving more, or braking, or accelerating.
I'd estimate the new speed is about 20mph.
I dont usually use full speed though, as 20mph seems a bit too fast on the board.
Used my iphone and GPS Lite software (Free from Apple App store) to clock the speed of the board.
Top speed was 22mph downhill.
On flat ground about 17 to 18 mph.
What feels safe to me is about 15mph.
I have enough torque to power uphills, and just use gravity to coast down.
Wow - didn't realize you had picked up a um70 - I have been rocking that same board for about a year or so...
I see you up'd the motor and batteries... I would really like to pick up some torque - also my lead acid batteries are about dead - can you revisit what you did with your dewalt batteries and talk about how long they last??? I'd appreciate it.