Another Stealth bomber (clone) build

[Gstegman]

Cool vid. What cells are in your EM3EV battery? Mine are 25r cells and they suggest no more than 100a from the battery. My BMS is 80A but they said 100 to 120 peak is OK. Bummer no wheelies at 100A, I was looking forward to looping out!

 

[Choppa66]

Hi,Bike is looking good and going well by the look of video. you say it got a bit scary with fish tailing at speed? I have the same frame that I'm building at the moment,first bike like this I have built. I did notice when I got the bike as a rolling frame that if you shake the bars from side to side then the swing arm will wiggle and fish tail about with the weight of the motor and wheel! I had a feeling this would be an issue when riding it at speed,have you still got the standard rubber moulded bearing/bushing in the frame where the swinging arm bolts to the frame? I have removed mine and replaced it with a pair of sealed roller bearings and a nylon spacer between them. This is a kit I bought from a guy on ebay uk. Bit of a pain to fit but I hope it will get rid of the wobbly swinging arm issue.

 

[shortcircuit911]

@Gstegman thanks man. There are some trails just off that road I'm on, so I might make a few more videos showing how this bike actually is an enduro bike and can be fun in both environments. Pack is made up of 25r cells, 100A BMS and I think they said 120A burst. I'm already thinking about making another pack so I can pull more battery amps, we'll see.

@choppa66 Yeah man it got a little hairy for a second because the road wasn't smooth. I definitely want to look into the issue and see if there is something I can do to correct it. It's really only an issue at like 40, not sure my tft screen is displaying the correct speed, so I'm guessing about 40-50 is where it gets interesting. Have a link for the kit you bought?

I was able to get out on some dirt trails by my house and it was pretty fun. I didn't go too far or get too crazy, butit was fun. I tried to climb a dirt hill from a dead stop and made it up about half way (it was pulling nice) before the bike just stopped. I think it was the BMS, but I'm not entirely sure. By the time I realized what happened and looked at the screen it was still on, but the bike wouldn't move when I hit the throttle. I shut the bike off for 10 sec and fired it back up and took off. I'm glad a simple restart fixed the issue because I was a couple miles from home, and I don't even have a chain :lol:

Quick update on the throttle. It seems that the cable has stretched a bit and broken in nicely. There is no longer that slight hum from the controller indicating that the throttle is being pressed ever so slightly. I can now recommend this mod with confidence.

Going to hit the trails again this weekend and have some fun.

 

[Gstegman]

Thanks and we have the same battery. I just fired up my Grin charger for the first time and plan to only charge to 85%. Once I figure out how I am going to better secure battery and charger I plan to grab the GoPro for a quick video.

FWIW I just reread emails from EM3Ev and they say the BMS is 80A continous, 100 peak. I set my Sabvoton accordingly.

 

[Choppa66]

Yeah I think that's probably what's causing the fish tailing,same as on a motorcycle when the bearings are worn out in swinging arm,can also get it on the front forks if the headset bearings are shot or need adjusting. I will see if I can find the kit on ebay and send you the link,the guy was really helpfull. I will take a picture of the bearings fitted in mine tommorow and post it on here,haven't got the swinging arm back on bike yet. You can probably just order the bearings in the right size and then use the existing tube/spacer that you have to get out of the rubber mount on the frame,maybe just have to cut it down a bit to fit between the bearings? The hardest part is chain drilling and cutting...cursing...sawing...that rubber bushing out of the frame!! Then just cleaning the section of frame out and pressing the bearings in with the spacer between them.

 

[Jonno]

Hi shortcircuit911

Some wider handle bars would help higher speeds 780mm +.
Also altering the head angle on the forks by lowering the rear end gives much more stability at 60mph +

Jonno

 

[shortcircuit911]

@choppa thanks, I'll have to look into this, because its annoying on bumpy terrain as well. I should be able to find some bearings and cut some shims on the laser.

@Jonno, thanks I might drop the back a bit and see what that does. Definitely need get this sorted out.

Well, I went for a ride on the trails by my house and it was pretty damn fun, that is until I fried my sabvoton. Did some trail riding, then ripped down the road for a few miles, then started doing some hard pulls. When going back to get my gopro I was pulling like 1-2kw then the bike just shut off, and wouldn't turn back on. Been trying to diagnose the issue with no luck, Electric God here on ES thinks it might be blown FETs. I'm going to send him my controller and see what he finds.

Pretty pissed with Sabvoton, no manuals or support, and a controller that can't push 100A reliably. I honestly just want to buy another controller. It is tempting to buy another sabvoton (200A model), but that would be a huge bummer if it crapped out on me. I don't want to spend more than $300-350 (less if possible) so I'm looking at options like the kelly kls7240s. I was looking at addapto, but am not sure how reliable those are as well. The search continues, just sucks that the bike is down until I throw more money at it . The ride was fun though.

Kelly controller:
http://evcomponents.com/controllers/sine-wave-brushless-controller-2kw-8kw/kls7240s-350a-72v-sine-wave-brushless-controller.html

Video:

https://youtu.be/kfVgrYKWPzk

 

[Geargrind]

@choppa66 Yeah man it got a little hairy for a second because the road wasn't smooth. I definitely want to look into the issue and see if there is something I can do to correct it. It's really only an issue at like 40, not sure my tft screen is displaying the correct speed, so I'm guessing about 40-50 is where it gets interesting. Have a link for the kit you bought?

Regarding the swing arm bushing, it defiantly is too soft. I haven't even completely put mine together and see lots of movement. For one thing on mine the id of the bushing is 12mm, the supplied swing arm bolt is 12mm OD, but the holes in the swing arm itself are almost 12.6mm ID. I shimmed the swingarm holes and tightened all together , but just sitting on the bike with wheels installed I can feel the rubber bushing swaying some..

 

[Choppa66]

That sucks about the controller going down!! Was it the 100 amp or the 150 that you have? I have the 150 but I'm nowhere near fitting it in the bike. Been a busy day today and didn't get chance to take a picture of swinging arm but I did find a picture of the kit that I bought to replace the rubber bushing with. Will also try to find the link from the guy on ebay but to be honest I think it's just as easy to buy 2 bearings, as long as you can get the right internal and external diameter bearings. When you drill out the rubber bushes there is also a thin metal sleeve that the rubber must be moulded into, that also needs to come out,bit fiddly to do but I managed the saw through a part of it with hacksaw blade and then just split it and knocked it out with an old screwdriver,think it's in 2 halves if I remember? Let me know if you need any more pictures.

 

[Choppa66]

@choppa66 Yeah man it got a little hairy for a second because the road wasn't smooth. I definitely want to look into the issue and see if there is something I can do to correct it. It's really only an issue at like 40, not sure my tft screen is displaying the correct speed, so I'm guessing about 40-50 is where it gets interesting. Have a link for the kit you bought?

Regarding the swing arm bushing, it defiantly is too soft. I haven't even completely put mine together and see lots of movement. For one thing on mine the id of the bushing is 12mm, the supplied swing arm bolt is 12mm OD, but the holes in the swing arm itself are almost 12.6mm ID. I shimmed the swingarm holes and tightened all together , but just sitting on the bike with wheels installed I can feel the rubber bushing swaying some..bushings.jpg

There's also a lot of play in the 2 bolts that go through the rear shock mounts to I noticed? Think the bushing in the DNM shock I have is for an M8 bolt,but the hole in the frame bracket is bigger! I'm just in the process of getting 4 small sleeves machined up to take the play out of that bit to.

 

[Choppa66]

@choppa thanks, I'll have to look into this, because its annoying on bumpy terrain as well. I should be able to find some bearings and cut some shims on the laser.

@Jonno, thanks I might drop the back a bit and see what that does. Definitely need get this sorted out.

Well, I went for a ride on the trails by my house and it was pretty damn fun, that is until I fried my sabvoton. Did some trail riding, then ripped down the road for a few miles, then started doing some hard pulls. When going back to get my gopro I was pulling like 1-2kw then the bike just shut off, and wouldn't turn back on. Been trying to diagnose the issue with no luck, Electric God here on ES thinks it might be blown FETs. I'm going to send him my controller and see what he finds.

Pretty pissed with Sabvoton, no manuals or support, and a controller that can't push 100A reliably. I honestly just want to buy another controller. It is tempting to buy another sabvoton (200A model), but that would be a huge bummer if it crapped out on me. I don't want to spend more than $300-350 (less if possible) so I'm looking at options like the kelly kls7240s. I was looking at addapto, but am not sure how reliable those are as well. The search continues, just sucks that the bike is down until I throw more money at it . The ride was fun though.

Kelly controller:
http://evcomponents.com/controllers/sine-wave-brushless-controller-2kw-8kw/kls7240s-350a-72v-sine-wave-brushless-controller.html

Video:

https://youtu.be/kfVgrYKWPzk

Just a thought and I guess you have checked already but just by chance if you haven't. Your bolts on your disc brake rotor haven't worn through the motor wires and shorted out the phase wires have they? Only on my frame I had to countersink the rotor and replace the bolts with countersunk Allen bolts because they were rubbing on the motor wire,and even then it's dead tight. Only I noticed that in your pictures you didn't have a lot of room and I'm sure I've read on here somewhere that that is a favourite for blowing up controllers. I hope you get it sorted soon.

 

[shortcircuit911]

@choppa, thanks for the pic and info. I have been keeping an eye on the rotor bolts since installing the QS motor and all is intact there.
Those mods you're doing should get that tiny bit of play out, my frame has clearanced holes (on the generous side) as well.


I pulled my bike apart (swingarm from frame) to have a better look at the bushing. I took some measurements, and assembled it with a thicker washer to see if that gets some of the play out. Will test and revisit if there is still an issue. The controller has been shipped to ElectricGod to see if he can fix it. He said that the FETs in it aren't the true infineon FETs that were once in the Sabvoton controllers. He's going to take a look at it and see what he finds, if it's a FET issue, an option is to swap them all out for better ones and have a 200A+ controller. The other option is to scrap it and get another one, it's a waiting game at this point. Hope everyone had a sweet Halloween!

 

[Choppa66]

Short circuit. That's ok no worries,good news about the disc rotor bolts I guess..but still a bummer about controller. well I hope the controller is repairable,got to be better and cheaper than having to buy another one so fingers crossed for you. Seems odd because from what i have read on here people seem to say sabvoton controllers are bullet proof...unless like you say they are cutting corners now and using cheaper components?! I hope the washer takes some of the play out of swinging arm, I know when put mine together and shook the handlebars the swinging arm just fishtailed about with the weight of the back wheel and motor! It is a mxus 5k though and a big old lump! I think it is just the fact that bearing/sleeve is mounted in rubber instead of a solid bearing? Not very good design really. Great Halloween costumes by the way.

 

[Garen]

@shortcircuit911 Did you get your TFT and controller as a kit somewhere? Seems one can't buy the TFT separately... I even tried asking several vendors, and the only one that would respond, said:

...
"our TFT Display and controller have communication protocol, your controller does not have this, it is not simple modification joint!
I really want to help you, but I don't want to sell products that you can't use. I hope you understand! Thank you"
...

So it seems I can't just go out and buy a sabvoton from the manufacturer and then get a TFT display separately, for some bizzaro reason.

 

[shortcircuit911]

@garen yes I bought them together. You're lucky you asked a vendor with a conscience. He/she is right, you can't just hook a tft screen up to any sabvoton as there are different wiring configurations on some of the sabvotons. Mine all connects together with these weird connectors and other models have typical ebike connectors, and I've seen another version as well. Honestly go with a cycle analyst if you can, the tft drops out at around 10kw, also you can't see ah consumption, watt max, and a few other pieces of useful raw data.just my .02.

 

[Gstegman]

I have the same combo and agree with shortcircuit911. While it is easy plug and play, it only supports basic functions. You can’t monitor motor temp for example...

Look very closely at the wires coming out of a Sabvoton as there are many different flavors out there it seems.

 

[Garen]

Yup, based on my experience in the last few weeks, many vendors often (1) don't respond to basic questions about their own products, or (2) at a certain point they stop responding, or (3) can't answer straightforward questions about their own products.. Which is SO damn frustrating. *@!$@#

This vendor was 'nbpower' on amazon. I had thought it was just a difference in the wiring and connectors, which is no big deal to change if I needed to.

Still wonder what "communication protocol" they're referring to. I noticed the 72200 has CAN-BUS connectors, so maybe the 72150 does too and they're just not used except as by some vendors who tap into them..

(A"10kw" limitation seems OK, but being able to see motor temp and amp-hour (AH) usage sure would be nice!)

I suppose there's already a detailed thread on using the CA-DP v3 somewhere in the vast sea of endless-sphere posts, and I just haven't found it yet. lol.

Anyway, if it weren't for the fact that the kits seem noticably pricier I wouldn't have kept looking for so long. I imagine the TFT display is maybe $100, and the 72150 is ~$240 from the manufacturer, but the kits online with them are over $500! Some look reasonable, but then when you inquire about shipping, they're like "No problem! That'll only be $238 for FedEx", which they say is cheaper than DHL or UPS for them somehow..

Yet somehow em3ev uses DHL and charges way less for shipping, so perplexing.

Anyway, looks like the options are to buy an overly expensive kit, or go the CA3 route. This looks handy:
http://www.cnqsmotor.com/en/article_read/Sabvoton%20Function%20Wires%20for%20CYCLE%20ANALYST%20V3,%20CA3-DP/416.html

 

[Electricglider]

That sucks about the controller going down!! Was it the 100 amp or the 150 that you have? I have the 150 but I'm nowhere near fitting it in the bike. Been a busy day today and didn't get chance to take a picture of swinging arm but I did find a picture of the kit that I bought to replace the rubber bushing with. Will also try to find the link from the guy on ebay but to be honest I think it's just as easy to buy 2 bearings, as long as you can get the right internal and external diameter bearings. When you drill out the rubber bushes there is also a thin metal sleeve that the rubber must be moulded into, that also needs to come out,bit fiddly to do but I managed the saw through a part of it with hacksaw blade and then just split it and knocked it out with an old screwdriver,think it's in 2 halves if I remember? Let me know if you need any more pictures.s-l1600 (5).jpg

Hi, can you please post he link to the ebay, my rear swing is ok for now, I grinded down the center of the bussing to level the frame, but it will not last.
Btw my 200A is fitting fine inside the frame. I have removed the battery box completly.
You need 200++Amp peak battery to get full power. 120A bms/240 peak is good for the QS.

 

[Choppa66]

That sucks about the controller going down!! Was it the 100 amp or the 150 that you have? I have the 150 but I'm nowhere near fitting it in the bike. Been a busy day today and didn't get chance to take a picture of swinging arm but I did find a picture of the kit that I bought to replace the rubber bushing with. Will also try to find the link from the guy on ebay but to be honest I think it's just as easy to buy 2 bearings, as long as you can get the right internal and external diameter bearings. When you drill out the rubber bushes there is also a thin metal sleeve that the rubber must be moulded into, that also needs to come out,bit fiddly to do but I managed the saw through a part of it with hacksaw blade and then just split it and knocked it out with an old screwdriver,think it's in 2 halves if I remember? Let me know if you need any more pictures.s-l1600 (5).jpg

Hi, can you please post he link to the ebay, my rear swing is ok for now, I grinded down the center of the bussing to level the frame, but it will not last.
Btw my 200A is fitting fine inside the frame. I have removed the battery box completly.
You need 200++Amp peak battery to get full power. 120A bms/240 peak is good for the QS.

Hi, I'm not sure how to add a link on here? But the item number is 302931571087. If you put that number in the search on ebay uk then you should find it. It's £30.00 to buy plus postage,but like I said before in other post you can probably just buy the sealed bearings on ebay for a few pounds and then make a spacer up or just use your spacer that is in the middle of the rubber bushing that you will have to remove to fit bearings. Hope this helps.

 

[Electricglider]

That sucks about the controller going down!! Was it the 100 amp or the 150 that you have? I have the 150 but I'm nowhere near fitting it in the bike. Been a busy day today and didn't get chance to take a picture of swinging arm but I did find a picture of the kit that I bought to replace the rubber bushing with. Will also try to find the link from the guy on ebay but to be honest I think it's just as easy to buy 2 bearings, as long as you can get the right internal and external diameter bearings. When you drill out the rubber bushes there is also a thin metal sleeve that the rubber must be moulded into, that also needs to come out,bit fiddly to do but I managed the saw through a part of it with hacksaw blade and then just split it and knocked it out with an old screwdriver,think it's in 2 halves if I remember? Let me know if you need any more pictures.s-l1600 (5).jpg

Hi, can you please post he link to the ebay, my rear swing is ok for now, I grinded down the center of the bussing to level the frame, but it will not last.
Btw my 200A is fitting fine inside the frame. I have removed the battery box completly.
You need 200++Amp peak battery to get full power. 120A bms/240 peak is good for the QS.

Hi, I'm not sure how to add a link on here? But the item number is 302931571087. If you put that number in the search on ebay uk then you should find it. It's £30.00 to buy plus postage,but like I said before in other post you can probably just buy the sealed bearings on ebay for a few pounds and then make a spacer up or just use your spacer that is in the middle of the rubber bushing that you will have to remove to fit bearings. Hope this helps.

https://www.ebay.co.uk/itm/Stealth-Bomber-Fighter-Electric-E-Bike-Frame-Rear-Swing-Arm-Bush-Bearing-Upgrade/302931571087?hash=item468820f18f:g:IcsAAOSwSz1au7Wp:rk:1f:1&frcectupt=true

Thanks!

 

[Choppa66]

Yes that's the one. I can measure the bearings that came with mine if you want to know there size so you can just buy bearings if you want?

 

[Electricglider]

Yes that's the one. I can measure the bearings that came with mine if you want to know there size so you can just buy bearings if you want?

Thant would be cool, the total cost to Norway is 30£+26£ shipping+15£ tax..... for some strange reason.
Can you also measure the lenght of the green tube?

 

[Choppa66]

Yes that's the one. I can measure the bearings that came with mine if you want to know there size so you can just buy bearings if you want?

Thant would be cool, the total cost to Norway is 30£+26£ shipping+15£ tax..... for some strange reason.
Can you also measure the green tube?

How much???? Shipping and tax is a ripoff!!! I have just measured them and they look to be 28mm external diameter,12 mm internal diameter for the 12mm bolt that goes through swinging arm and I think 8mm wide, I have just looked on ebay and it's a 6001 series bearing by the look of it and there £2 each!! The green tube I can't really measure because it's in frame but the frame is 62mm wide so minus 16mm for the 2 bearings makes it about 46mm? I think you can probably use the spacer from the rubber bearing if you clean the rubber off of it and may have to cut it down a bit because it's longer than 46mm. I would wait until you can try the bearings for fit before you remove the thin sleeve from the frame that the rubber bushing is moulded into as you may be able to leave it in there and just clean the rubber off of it?

 

[shortcircuit911]

@electricglider and choppa, thankd for posting the links and your ideas, awesome stuff.Yeah those bearings are super cheap on ebay I'll get some too. I intend to fix this issue on my bike, but I have bigger fish to fry at the moment.

Still no word on the sabvoton. So we'll see how it goes as far as the controller, might have to ask santa for a new one.

So I've been playing around with batteries at home and had some cool results. I had a hoverboard battery pack that I cut up for the cells and decided to experiment. I also had a 4s BMS I got from ebay for like $4. I got everything wired up and this little pack rips in my kid's 6v quad, he rode a wheelie and did a 180 in the driveway, didn't catch it on video though. I'm going to keep experimenting and eventually build myself a new pack for my bike as my current packs BMS is a 100A, this bike needs 200A! I've ordered parts to make a spot welder out of a battery, timer, and foot switch, hope to have it up and running soon. I'll keep you guys posted.

 

[Choppa66]

No worries. Hope you get it sorted soon. Kids quad sounds cool. 8) have you seen a couple of guys on YouTube,think there both members here to? Guy called vortecks and another guy Andy Kirby,there both trying out a new BMS for there bikes, the vortecks guy has been developing the software for it I think and he is selling an APP for it so you can program all of it through bluetooth and your phone. Looks good,not sure how much the BMS is but i think the APP is about £6? There both building new battery packs as well,might be worth a look.