Another Stealth bomber (clone) build

[efMX Trials Electric Freeride]

Placed an order with QS for the 138 2000w mid drive motor with 12t 428 sprocket. You know what they say "No QS Motor, No super EVs!". I think I'll finally be happy with the bike if I can make it work. Power wheelies should be no problem and hill climbing ability will be insane. Next step is to measure the hub so I can get a custom rear sprocket made. Planning on running the bike 7:1 and see what that gives me. I'm also planning on ordering a 13t sprocket from the same company just so I have a few gearing options. QS says they'll be shipping within 9 days, so we'll see when when it shows up. Until then I have a lot of thinking and experimenting to do in order to try and get this to work and be as balanced as possible. The pic below is what I'm thinking, but that may change, we'll see.

do you have the link for the motor or kit?? how much $$$ ? does it fit standard 428 sprockets or custom to fit the shaft from QS?? what is the shaft diameter and interface?? would it fit standard 420 sprocket instead?? I want one of these motors as well for my other bike..

 

[shortcircuit911]

Motor $350: https://www.aliexpress.com/item/4000076478471.html?spm=a2g0s.9042311.0.0.614e4c4d2OIcNl

13T sprocket$13: https://www.ebay.com/itm/223419406509

This is the closest I could find online. I can probably machine it a bit if its too small.

Custom rear sprocket $103: https://sprocketspecialists.com/product/rear-sprocket/

Chain (2) $70: https://www.ebay.com/itm/NICHE-428-Drive-Chain-136-Links-O-Ring-With-Connecting-Master-Link-Motorcycle/293470839643?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

I haven't looked at 420 sprockets, you could probably find something out there though.

I'll be wrapping up the cad over the weekend and plan on cutting parts this coming week. I should be able to cut and weld them pretty quickly, likely by the end of the week when all the parts hit.

 

[trazor]

Just subscribed. Great work. I want to see the QS in action! I will consider it for my bikes. Thanks for sharing.

 

[shortcircuit911]

@ trazor thanks man!

I wrapped up the cad on the side mounts this weekend and managed to make an acrylic version to get an idea of how it will look. I'm pretty happy with how it turned out and am planning on getting them waterjet so that I can make the mount out of aluminum. There will be some other features I'll need to machine in,but the shouldn't be an issue. One of the sides of the mount will be welded and the other side will be bolt on. Doing this will allow me to remove the motor easily, and do so without spacers involved. Parts should be coming in very soon so I hope to make some progress in the coming days.

Looking at the swingarm and where the chainline will be I've decided to modify the swingarm again. This time I'll only be modifying the drive side. I plan to cut it and move it outward 20mm. Doing this will allow the chainline to move to the right that amount which will allow the motor to sit pretty close to center in the bike. I still have some planning to do on this, hope to make progress soon.

 

[shortcircuit911]

Made some progress on the build, but still waiting for the rear sprocket, hardware, and steel for wrap up. The swingarm has been extended to 8 1/4" it pretty solid for a test ride but will require more work for the abuse it will see. The waterjet sides also weren't done so I have the acrylic ones I made to use as a mock up. Overall its looking pretty good. Most of the stuff should be in early next week. Lots of welding to do and a bit more fab but next week should be a big week.

 

[shortcircuit911]

Got the waterjet parts today and was able to get the motor mount welded up. I also made a spacer for the rear hub which will shift it outward 30mm to get me in the ballpark of where I want the chainline to be. After some mock up I got the motor clamped and bolted onto the bike. I'll going to make the last of the parts for the swingarm so that I can finish weld it. The last part I need is the custom 84t sprocket. It should be here tomorrow or the day after. The last part I need to make is a chain roller to keep the chain away from the pegs. Hopefully a test ride this week/weekend.

Video:
https://www.youtube.com/watch?v=vTJiZbTGVSo

 

[shortcircuit911]

Finally got all the parts in and did the last bit of fitment to go for a test ride. So far I'm pretty happy with the results. Top speed is around 44 mph, pulled just under 12kw, 350A phase, 100A battery. There is still some tuning and some tweaks that need to happen, but pretty happy so far.

 

[amberwolf]

That's a big sprocket. I suppose if you get stuck with a log across a trail you could use it to cut it into manageable pieces.

 

[Yermommy]

That chain is going to cut your foot off if the roller ever breaks or if the chain breaks. Have you considered putting a chain guard over it? Everything else looks amazing.

 

[shortcircuit911]

@amberwolf ya it's also sharp af.

@yermommy thanks for the note. That was a temp idea that has been scrapped. I should have the new setup done this week. By next weekend I should have a chain guard and new roller configuration. I'm also modifying the peg mount to be stronger and out of the way of the chain. More coming and probably some video.

 

[E5J7R]

Hey man , what is that rear fender you have??

... i found one of those front fenders on ebay for 80$ buy it now (pricey but I can’t even find out how much they were new) ... nice bike btw. I have same frame!

Thanks for this thread too!

 

[shortcircuit911]

@E5j7r it's a rear fender for a honda crf 50. I think I got it on ebay for like $10. The front fender was on ebay as well, it was a little expensive, but not that expensive. Maybe they don't make them any more.


I was able to put in a few hours on the chain guard and new peg mount. I was also able to move the roller to a better place. Planning on putting it through the paces this weekend and making a video.

 

[shortcircuit911]

EEB+QS120 test ride video: https://www.youtube.com/watch?v=1RaA5pfq_ZE&feature=youtu.be

 

[ebike11]

EEB+QS120 test ride video: https://www.youtube.com/watch?v=1RaA5pfq_ZE&feature=youtu.be

Wow thats a giagantic sprocket!
Just curious...why wouldnt you just use a powerful hub motor?

 

[neon]

https://www.youtube.com/watch?v=JSkb0b35Wnc


hello everyone noob building eeb enduro

Here is my build , atm im running 18s = 3x 6s 12000mah aliexpress lipos im going to put 4 batteries in series and 4 paralell so i get
24s . 24ah , also need a 24s bms and charger , .

i really dont like the zoom forks , wanna swap with dnms , just finisehd the ebike ,
specs

motor : qs motor 205 250h 3t high speed version
controller : sabovton 72150, gonna swap it out with bac 8000 ,when i can afford it

can i use the qs motor with the bac controller or do i need qs 273 ?

first off make a proper batterypack that can handle the load of the motor

i also used beefy brakes at backwheel , i had some zoom brakes but those where terrible
i havent got around to mount front brake yet , im moving so havent had time to fix it yet

 

[mcclead2]

I am starting to wire up my first ebike - I have a query regarding the wiring of the throttle - does it connect to PAS wires on Sabvoton 72v 200A?

 

[ebike11]

Hi...has the fish tail issue been solved on these frames? Read a lot about the bushings etc in the swingarm.
Thinking on getting a used kit if I can avoid the wobble at high speeds with a qs273 thanks

 

[sitzme]

Some frames have gone to bronze bushings in the swing arm pivot and others are using ball bearings. My new build has the bushings but the swing arm bolt is not the best fit so it is going to be replaced. That said, at 55 mph it seems stable but it has not been ridden much at that speed.

Research rubber bushings of some kind in the early swing arm bearings. What I read indicated that they were problematic and many replaced them with ball bearings.

 

[imval]

I had the fish tail issue.

Removed the crappy bushing and replaced it with two bearings with a spacer in the middle and never had a single issue with it ever.
Highly recommend it!

 

[ebike11]

I had the fish tail issue.

Removed the crappy bushing and replaced it with two bearings with a spacer in the middle and never had a single issue with it ever.
Highly recommend it!

Glad to hear...what top speed were you able to test at?

 

[imval]

For everyone interested, here are the bearings I used: IBB Kogellager 16101 2RS (12x30x8mm)
4 of them with a spacer I 3D Printed in the middle to keep them from moving around.

I'm doing around 70kph on my bike, so not insane speed but I can absolutely feel a huge difference in the handling of the bike, especially in corners!

 

[ebike11]

For everyone interested, here are the bearings I used: IBB Kogellager 16101 2RS (12x30x8mm)
4 of them with a spacer I 3D Printed in the middle to keep them from moving around.

I'm doing around 70kph on my bike, so not insane speed but I can absolutely feel a huge difference in the handling of the bike, especially in corners!

Thx friend....found the seller on ebay with the upgrade. Is he a member on here by any chance?

https://www.ebay.co.uk/itm/304494066872?mkevt=1&mkcid=1&mkrid=710-53481-19255-0&campid=5338722076&customid=&toolid=10050

 

[imval]

I've got 4 of them shipped to me in the netherlands for 20€ from this website: https://www.lagerkoning.nl/
Then a half hour print of a spacer and voilà.

 

[ebike11]

I've got 4 of them shipped to me in the netherlands for 20€ from this website: https://www.lagerkoning.nl/
Then a half hour print of a spacer and voilà.

Thx but I dont have a 3D printer...Ill need the spacer too