10KW E-PK Ripper EXTREME!!!

[safe]

http://www.motoredbikes.com/attachment.php?attachmentid=17107&d=1240085865

Recumpence is actually the guy that got me thinking about motor rewinding. These RC motors have two big advantages over the typical motors we use for ebikes. First, they are brushless which means less friction and that increases efficiency. Second, all these RC motors are wound so that they use VERY LOW resistance in their windings.

It was when I realized that low resistance allows more power at lower voltage that I started doing rewinds.

14 horsepower is definitely realistic too... (dual RC motors)

These little motors have potential that are not being exploited by most people.

A Third good thing is that these RC motors are really, really lightweight. So you are getting power levels out of them that equal the big 25 lb Perm or Etek motors while weighing less than 5 lbs each.

 

[veloman]

Awesome job, wow. Clearly that took some skill and hard work to put together. What is your 0-30,40,50,60 mph times?

That is serious badass.

 

[safe]

It's Recumpence's bike... my guess is that he's been posting his bike on every electric bike related forum and will get back to this one eventually.

 

[recumpence]

I haven't run it yet. I am out of state right now. I should have it running in about a week or so. I am guessing it should do 0-40 in about 4 to 5 seconds considering what my recumbent is capable of........... That is if I can keep the front end down.

Those motors weigh 3 pounds each.

Matt

 

[safe]

I can still remember the days when the "high and mighty" talked about their 25 lb hub motors as the "Holy Grail" of ebikes because they could produce some decent power.

3 pounds each... that's just incredible...

The "secret" of these little motors seems to be that they spin fast and flow current easily. I've used that and copied it into the generic brushed electric motor and found results that are excellent too. (you might check out the rewinding thread) If you hadn't arrived on the scene with the RC motors (and stunned us all) I doubt that I would have ever imagined that it was possible. The RC motors got me thinking.

 

[AussieJester]

GREAT to see you over here Matt i seen you have been a member for awhile too...I'm loving the PK Ripper definitely the ballsiest rc build about and definitely the most professionally done .. How far odd is the video of it in action and you flipping it at 30mph?!?@#?!??!? hehee...Best of luck with the final steps of the build mate...

KiM

 

[safe]

I want to see the "Worlds First Ebike Backflip" too.

Just be sure to get a foam pit to practice... the pro's make it look easy, but that's because they spend hundreds of hours practicing in the foam pits. Don't practice it without the protection...

 

[recumpence]

Holy COW!!!! INSANE, INSANE, INSANE, INSANE!!!! FREAKING frighteningly VIOLENT!

They don't make smileys big or crazy enough!

This thing actually scared me pretty soundly. Holy ****!!!!

So, at 75% charge, I couldn't take it anymore. So, I took it off the charger and went for a ride. HOLY ****!! This thing is almost too powerful. I nearly flipped it a bunch of times. It winds out about 40mph. But, at what feels like 35, I hit the throttle while leaning over the bars and it still wheelied! I had no idea it would be this crazy. WAAAAYYYYYYY beyond my wildest expectations!

Man, oh Man, this thing is WICKED!!!!!!

I have to find someone to video me. But, it is hard to get a handle on the power without riding it.

Oh, did I say INSANE?!?!!!

Triple wicked!

Total E-diction!!!

Matt

 

[mabman]

Nice Matt. Keep the rubber side down!

 

[duivendyk]

Seems totally nutty,normally running at 600W for 45 mins at 6% of peak power.You should take up dragster-electric racing next.