Ktronik Kommuter / E-trailer 1st build (pic heavy)

Hey,

Built up a 24v /26" banfang into the rear of my BOB trailer...running from a 18A (modded for 48v) controller, powered by 9Ahr 48v LiFe pack, on my Surly Karate Monkey 29er. Custom cruze control & dynamo driven LED lighting system





Bike fully built (even wheels) by me, running solid rear axle & bob nutz.







to the left of the gear numbers is the 'GO' button



& the magnetic brake reset (which cuts the cruze control throttle button when braking)



Very basic cruze control using 1/ 5v relay & a feed back loop (latch link), I added a dropper diode just in case my controller did not like the full 5v, so now it sees 4.3v on throttle signal input. The controller is modded with a 12v zener reverse bias to the LM317 (PCB reg) so it still sees 36v + a few caps were changed. Extra heatsink added to controller box just in case.

Custom lighting system by me, driven from dynamo hub, with circuit to give 12.4w rather than 3w, in to cree R2 bin LEDs we get 750lm output (HID lights ~450lm)





Also to let people see how easy the martin basic circuit really is, I have re-drawn it, with a pic of what the parts look like the way I build it (dead bug style)...each step is the same circuit, just re-drawn so its easier on the brain...



as its a 26" hub in a 16" wheel, it goes up any hill I throw @ it... top speed up a hill 27 km/hr & 29km/hr on the flat...72v of LiFe is on order as is a V2 controller.

enjoy

Ktronik

That looks real nice. My old style BOB trailer would not accept a motor of any type in the stock fork. It looks like the new style BOB is a great match for the hub motor.

Built up a 24v /26" banfang

Click to expand...

I assume the 26" noted above means the motor was originally in a 26" wheel, since it looks like your motor is now in a 16" wheel. That should give you terrific torque at 48V. What kind of top speed on the flat does it provide?

:drool:

I feel like I should be paying to view these pics...

I think you might be the first person to combine electricity with a 29er.

Nice motor too! Is it the 180W or 220W version and is it noisy at 48V?

Rassy: Yep it has 26" marked on it, I guess thats what its for...& it really does pull, err push, up hills...infact I can do burnouts no problem @ all... New BOB has much more clearance & looks a stronger build. ~ 29km/hr on the flat, with a light pedal.

Ben: The more I can help others to 'go bike' electric or not, the better for me & the planet, I hope to have a solar / wind recharger station going real soon. Motor is a real 'sleeper' small but powerfull & the freewheel is very good, no friction @ all. Its marked 220w & is only heard when hill climbing, its the only way I know its on...other than that I can't hear it at all...but on 72v I would say it would make more noise... I was a bike mechanic for 20 years & now a electronic tech, so I had the good mix of skill to get it all going...I try to make everything as simple as I can so people can copy, my LED lights are very bright & super cheap to make, I have light housings ready for people to build if anyone needs... & 29ers are the natural option for committing, tough & fast...

thanks for the kind words guys...

Best

Ktronik

Wonderful !

But why a dynamo for LED lighting ? I thought dynamos were dead... How efficient ?

mikereidis said:

I thought dynamos were dead...

Click to expand...

not any more, the circuit I am using has revitalized dynamo systems around the world & now has quite the following, the old incandescent dyno light would put out ~60lm, mine puts out 650lm, as I have changed the power curve the dynamo tracks the speed @... a dynamo is a current device, like LEDs & with the new circuit, has max power @ 30km/hr rather than 15km/hr, giving 12.4w rather than 3w, so now is brighter than a standard HID bike light.

Sure not as efficient as running from a battery pack, but if my main battery pack goes down or I need to ditch the trailer, I still have light. better than running a second battery, as I would have to charge that as well, its a simple reliable system that works no matter what...

If I was to buy a LED battery powered system (same power output) from a bike shop, in Australia, I would be looking @ ~AU$500-$600 & would still have to wait a few months for R2 bin LED lights to come out. + I would still have to replace the batts over time...less money on lights means more money for batts, for the motor...

K

Kick-ass.

Dang those are some tall looking tires. What are they 700 2.0?

It's a 29er (29"). I need to get me one, I'm too big for a 26"

Good news on the speed, it correlates perfectly with my Bafang spreadsheet.

I'm not sure how the motor will take 72V, after all that is 3x the rated voltage.

700 28" 29er are all 622mm, this ones got a big gap between the fork and tire so I thought he might be running 26" tires. Wheel looks huge but may be an optical illusion.

Was window shopping earlier on some cushion 700 tires, looks like you can get 2.35 big apples in this diameter.. anyhoo nice bike, nice trailer.

The front does have a massive gap. The rear wheel looks about the same size and I doubt you could get a larger rim in there, so the front is probably a 29"/28"/700cc/whatever you want to call it.

Ben & Ice are both right, 700c running 'Marathon XR' tires, best touring tire on the planet, never wears out I have some big apples in the shed, fat & yumy.

But what tricked most was the suspension height adjusted, rigid cromo fork. So when you put your nice set of rockshox rebea fork in, it all handles the same. The Surly KM is rated as THE toughest 29er there is, Built with velocity 'tandem' 700c rims for extra strength, using only DT swiss stainless steel spokes...its a very well made cromo frame, which is hard to find these days in the world carbon & aloys.

My wife vetoed the 72v, she said better to get her going, than me faster, so she gets one as well...all good.

K

Just noticed that U are running a 16" trailer wheel with the Bafang. What size spokes did U use. I may go to a 16 for the rear of my trike, since I only need 20 mph or so, but need the off the line torque much more!
otherDoc

I think its 10g... 2.6mm dia...

K

Do U have a length! I may have to use my motor in a 16" wheel! I think 2.6 is a 12 ga, atleast from Crystalyte.

otherDoc

80mm long from spoke head bend to threaded end (measured in wheel) so it is not exact.


K