Posts
532
Joined
9/15/2009
Location
Olive Branch, MS
US
Edited Date/Time
9/25/2018 7:22am
It took about a year longer than I expected but my 5 no wait, 6 year olds bike is finally finished. The timing actually worked out in my favor. I had pushed him too far too soon and riding was way down on his list of "fun stuff". Now he is begging to ride all day every day. Hopefully we will have some action video this weekend. We are at flood level catastrophic thses days, but maybe we can find some dry ground.
Found out a few weeks ago KTM is going to all electric 50cc bikes just aboiut in time for my son to get on a 65. So we will be back at it soon. I'll probably need to start last week...
https://youtu.be/ASsHoo_udd8
Found out a few weeks ago KTM is going to all electric 50cc bikes just aboiut in time for my son to get on a 65. So we will be back at it soon. I'll probably need to start last week...
https://youtu.be/ASsHoo_udd8
Kick ass job man! Can't wait to know top speed, and battery life.
We've got 3 6 cell lipo packs. But I'm probably going to lower the voltage and try to get more capacity. Have not tested a full charge yet, but it sho uld be 25-35 minutes.
Top speed is around 45 mph. I'd like to slow it down some and the lower voltage will cover that.
The Shop
It weighs 78.6 lbs ready to ride. Stock it was around 86 I think. Add 3'ish pounds for a tank of gas and we are right at 10 pounds lighter.
If this motor can't take the heat, the next step up is a water cooled brushless motor. I'll plumb in a 12v inline pump and use the radiators.
It's practically flooding here these last few weeks, so I'm not optimistic he will get to ride this weekend.
Here is an old video of his modded Oset. It has a 500w motor vs 1400 on the KTM and we were running 36 volts/100 amps vs 72v/180 amps. The suspension was also sub par...
Theoretically this thing is around 10k watts. But that is unlikely. Oset rates their controller at 100 amps and we are running a 200a controller. They use 48v batteries and we are using 72. They rate the motor at 1200 watts.
So I am guessing we may be at 3600 watts which is something like 7-8 horsepower. I saw a dyno sheet for a 2014 ktm 50sx. stock HP was right at 8, but with exhaust etc, it climbed to almost 12.
A general rule of thumb is 5/3 HP gas to electric. So if a mildly modded 50sx is 10hp we would need 6hp to compete. I think we are okay for power, but really can't know for sure until he gets the bike on the track.
I'm to the point of bragging now... But, Justin Thompson and the JetWerx crew just built us a sweet, safe, fun practice track! Sorry about the video quality. I fly a drone almost as badly as I ride a bike.
https://youtu.be/RJO0sYcM0zk?rel=0
best bike stickers
The motor is from the Oset 20r. They are readily available and inexpensive brushed motors. The controller is from Kelly Controls. It is a relatively simple controller but is affordable and pretty simple to wire up and adjust.
I got a really cool hall sensor throttle control that uses the stock throttle and cable. You modify the end of the cable to attach to a magnet in an aluminum tube with sensors that convert the cable movement to a signal for the controller.
I am starting the research for a 65 build. At the rate I get things done it will take a couple years...
Pit Row
https://youtu.be/vBoftf7FLmE?rel=0
How did you take a part like this:
https://www.ebay.com/itm/1000-W-48V-DC-1020-electric-motor-kit-w-base-c…
...and get a "standard" sprocket on it, so you could use a regular moto chain or whatever?
thanks
When you get ready, start a thread here and we can track the whole build. I just picked up a bigger 50 for my son that I am starting on today. He had a ktm mini and this one is a husky tc50. But the bikes are very similar so not much will change.
My gut tells me that for an 85 size bike you will need a watercooled brushless motor. That comes with its own set of benefits and difficulties. But I would definitely start there. It may even be best to have the bike now, for measurements etc. Just be prepared for the manufacturers to announce factory electric 85's right around the time you finish yours. that's what happened to me!
Looking forward to seeing your 85 get finished!
Post a reply to: Finally finished! Electric 50sx