Another Stealth bomber (clone) build

@rumme cool build, I like those tires a lot. I actually read one of your posts a while ago where you talked about going tubeless, very cool.

I haven’t done too much to the bike lately (expecting another kid next weekend) but I did start making some side panels to give the bike a bit of a cleaner look. I made a quick back fender by cutting up some black plastic I had. I ordered a rear fender for a cr50 off of ebay, so hopefully that shows up soon.

I’ve been going back and forth with QS, they’re taking a while to send me an invoice, literally just trying to pay them money and they won’t let me. If all goes well I’ll have the new motor in a month or so. I haven’t been basing much lately as I want to baby the motor as long as possible and have it as a spare.

Last thing I’ve been working on is getting the stock controller cover/enclosure that came with the bike to work with the beefy sabvoton. I ended up sliding the cover down to cover the sabvoton and notched a few areas so that it clears the crank and sabvoton mounting bolts. I still need to make a small bracket for the top and finish the plastic portion that will house all the wiring.

So I don’t think I asked my question clearly above and I want to re-ask. If you look at the picture below you’ll see the hall connections I have. On the motor side there is a white wire for the thermistor, and on the controller side of town there is an empty slot where the thermistor should interface with the controller. Do I need to run the white wire somewhere else? If so, where? I don’t see another connector for it. Any help there would be much appreciated.

In the same boat with a 72150 missing temp. Are you running a breaker or battery switch? I am not comfy with just the on off that came with display. I am just not sure what breaker amperage to use if I want it to trip above 100A. From what I have read they dont actually trip at rated value but I am still learning.

Very clean well sorted looking build!

Thanks man, I appreciate that. At the moment I'm using the power switch that is connected to the display. I thought about fuses, but decided to move forward without one. I set the MAX amps in the APP to 100A and the BMS has never tripped. I might eventually ditch the tft display for a cycle analyst, I think at that point I'll add a main power switch. As far as breaker tripping you could get like (2) 50A or 60A breakers and experiment with wiring them in parallel. I don't have much experience with them, but have seen people use simple AC breakers on their bikes.

Or maybe something like this:
https://www.ebay.com/itm/Ignition-Protected-100A-Large-Current-Overload-Circuit-Breaker-Reset-72V-Boat/332748667308?hash=item4d795db9ac:g:L1IAAOSwuPlbZy~s

Just went for a rip on the bike, and if I keep it on 3 it stays in the 4-5Kw range and is still fun to ride (10Kw is more fun). When I put the bike on 4 or 5 and start pulling 9-10Kw, I hear a bit of noise (like a light knock), so I usually let off. When I got home the motor temp was fine. So I think I'll keep it on 3 when I ride it, but I'm curious what that sound might be, its only when I'm pulling lots of power. Heard back from QS going to place my order in a bit, then I can sleep.

Hi

Congrats with the nice bike!
I built mine this spring. The Zoom fork is really a piece of s... I ditched mine after a few runs.

@electricGlider nice bike, I like your suspension; is it worth the money?

Well I finally got my order placed with QS, their site said they typically take 2 weeks to lace it up and ship it to you. That should solve all my motor/performance issues. I went for a ride to day with the bike on 3 and accelerated hard a few times while rolling at 10mph or so and heard 3 knocks coming from the motor, so I let off and slowly ramped the throttle back up (slower this time) and it was fine. The bike did that twice today, so that sucked. I'll continue to thrash this motor until the new one arrives.

shortcircuit911 said:

@electricGlider nice bike, I like your suspension; is it worth the money?

Click to expand...

Totally worth it! The DNM cost about 400$.
Before I got the bike I read a guy calling the Zoom "an object shaped as a fork" and I thought that was not possible. But I totally agree with him now. It has no feel of the road and is like a pogostick in the terrain. Sorry to say.
But is is still ok to start up with, it cost 90$ with the frame.....

Zoom test in German, but you understans https://www.youtube.com/watch?v=OeeR5YEqbxE The clack clack sound in the video is very real.

The video manual from the frame manufacturer https://www.youtube.com/watch?v=Pb-XXwEzkNM

Man I need to get a set of those, not sure when though. The zooms do suck ass though, I can confirm this. I did turn both the front and rear adjuster in the stiffer direction.

I made a bit of progress this weekend, even though the bike is damn near worthless until the new motor and wheel show up. The first goal was to enable charging without having to remove the side panel. I had an XLR charger port laying around, so I decided to make a little mounting plate out of the plastic I had, to mount it to the frame. The battery has a set of anderson's coming out of the bundle which is the charge lines. I just made a quick adapter to make the XLR work with the charger output and I was in business. I may make another with a bit more length because the one I made is just long enough to charge the bike with the charger on the ground.

The second goal for the weekend was to get a small enclosure made up that will house all the wiring at the bottom of the bike. The enclosure is probably one of the ugliest things I've ever made, but its going to work nicely. I used plastic, rivets, and rtv to make the enclosure. I still need to do a bit of trimming but it should be done soon.

Went for another spin on the bike and the motor keeps making noise when I pull too much power, even when the bike is on number 2 or 3, the problem gets worse with heat. So I'm basically babying the motor until I get the new one which was just ordered last week. I hope it comes sometime in October, but it may be November because there is a week long holiday the sales rep was saying it wont go out before then so...

I like the mini Ferrarri F12, you HAVE to mod it!

@gstegman installed a brushless setup in it last year, radio controlled, it does crazy doughnuts with my kid in it. Pic below

So the wife just had our second kid this past weekend, so progress has come to a crawl. I have been able to do a few things in the past few days. First, I received the crf50 rear fender in the mail and it is a perfect fit for the seat. The mounting tabs and cutouts match up perfectly between the two, see pic below.

Last week I received some ABS plastic sheets to box in the sides of the bike and keep crap out. I started covering some of the gaps in the seat frame as you can see in the pic below. The bike is starting to look cleaner with the new fender and side panels. I have some parts arriving this week for a new throttle, I figured I'll get that switched out while I wait for the motor. Still no word from QS, I'd imagine it'll be a few more weeks before I hear from them.

Back with more

Im building a similar bike using the same frameset. The hardest part living in the US (eastcoast) is finding suppliers for parts. I ordered the hubmotor laced to a 19" moto wheel and matching front rim from Ncyclebike (aliexpress) and have been waiting for delivery for about 3 weeks at this point. What has been your experience on receiving goods from other countries? Did you have any import duties, taxes or similar issues on any of your purchases? Thanks for any info or advice on suppliers for folks in the US..

Shortcuircut911. Congrats on your new kid, awesome mod job on the car! I am looking at fenders so good info there, what is the front fender?

Geargrind, I ordered front and rear wheels with tires from the same vendor and they are suprisingly true!

@geargrind welcome to the forum, and ebike building. I had a similar issue with my wheels and controller. The supplier was late shipping everything so I got a bit worried and even had to threaten him at the end there. One thing you have to remember is that many of the vendors on aliexpress make your order after you pay for it, they don't always have stock available for immediate shipment. I placed an order with QS September 27th, and I probably won't see it for another 2 weeks or so. If you haven't heard anything from the vendor, or they've missed deadlines definitely get aliexpress involved, otherwise they're probably just slammed with orders.

As far as duties and taxes, no nothing out of the ordinary. What's left on your build? I get parts from amazon, ebay, EM3EV,and aliexpress when I need to, you should be able to find what you need there. good luck with the build, post pics or ask for help.


Not much progress with a new baby in the house. The wife immediately gives me the death stare when I go into the garage. I did bump the regen amps up to 80A, but I think I want a bit more because the brakes I have don't have enough "grab". Slowly working on boxing in the seat frame and fender area so that it will be easy to clean when I take it off road.

I received all the parts to convert the bike to a proper dirtbike throttle. I ordered a pitbike throttle kit off of amazon for $13 or so and then ordered a throttle adapter :http://www.eastgem.net/throttle-adapter.html
I'm slowly assembling it on the bench then I'll install it on the bike. Still working out how I'll do this, but will likely cut the throttle connector off of my current throttle (special 3 pin connector that mates with sabvoton) and connect that to the adapter. This will be a much more robust solution when riding off road. I grew up on dirtbikes and often like to get silly, so chances are I'll drop this bike. If the bike lands on the throttle side I don't want it to break, and the stock one IMO would break immediately. I hope to get this integrated into the bike before the motor shows up, we'll see

I took it to the park the other day and it's fun to ride, but I really just want to get the QS installed and ride some wheelies.

@Shortcircuit Congrats on the new little one , I am sure there has been a lot of excitement in your household.

Reguarding ebikes I have built 3 (what I call normal, cheap hub motor controller bikes) and a scratch built recumbent e trike in the past. But recently( last month ) decided to tackle a EEB build. Ive been a long time lurker of the forum and decided I had better create an account ,lol.
I had no issues ordering the frameset and fork from china (alliexpress) and couldn't believe I received it in 5 days via a courier at 9:30 pm one night ! I live out in the country in PA on a dirt road non the less. Our local little town doesn't even have a traffic light ! Anyways, I have sourced most of the parts via amazon, Ebay , bike shops etc. I placed the laced wheels and hub motor order on sept 28th , I got an email saying they were shipped on the 8th of October and to expect delivery within 5 to 7 days with a fed ex ie tracking number....but that number is no good. I contacted the seller and he replied last night that he will look into the issue Monday. I still need to order a controller ,(leaning towards a Sabvoton 150 with tft), but have reservations that there will be no thermo wires to monitor hub temps. Also I need to order a 72v battery that will fit into the frameset. Wondering if anyone that runs the Sab 100 amp had issues with the missing temp wire on the controller side ? Thanks for the advice and you have a nice build going on.

Gstegman said:

Shortcuircut911. Congrats on your new kid, awesome mod job on the car! I am looking at fenders so good info there, what is the front fender?

Geargrind, I ordered front and rear wheels with tires from the same vendor and they are suprisingly true!

Click to expand...

Gstegman, Thanks that gives me a little more hope, now I just to receive them here ..lol

Most welcome, I went thru the bogus tracking number thing as well. Add one week to the first date you see and you will have your stuff. I suspect they use a freight forwarder to move product from China to US. Once the product is here the real tracking number pops up with a real delivery date.

Thanks for the love on the new baby boys.

@geargrind glad you decided to make an account and contribute. Also glad to hear that you have ebike building experience and know where to get parts. As far as the bullshit tracking number, yeah that's pretty common on aliexpress. My frame and forks showed up super fast as well, but the supplier told me they had stock on hand before I made the purchase. The seller I bought my current wheel from took a good 3 weeks to lace and ship my order, plus another week or two to get here depending on shipping method.

@gstegman, sorry didn't see your post above earlier. The fender is THE and it was purchased from ebay.

Front fender: https://www.ebay.com/itm/T-H-E-Proline-Front-Series-Front-Mountain-Bike-Fender-Black/291925066358?_trkparms=aid%3D555018%26algo%3DPL.SIM%26ao%3D1%26asc%3D20131003132420%26meid%3D7fd798d5ce18499e932103edfa27d310%26pid%3D100005%26rk%3D2%26rkt%3D3%26sd%3D122208758783%26itm%3D291925066358&_trksid=p2047675.c100005.m1851

Rear fender: https://www.ebay.com/itm/Plastic-Rear-Fender-Mudguard-Cover-For-HONDA-CRF50-XR50-Dirt-Pit-Bike-7-Colors/291949361083?ssPageName=STRK%3AMEBIDX%3AIT&var=590939782799&_trksid=p2057872.m2749.l2649

Thank you sir, ordered the rear soon after your post. Might try to monkey with side panels. I suspect I am in the minority with respect to this forum in that with my build I am shooting for a motorcycle look.

I have an extra set of plastic for my JDM XR100 Motard I might try to steal from as well.

Thanks again!

@gstegman yeah most people don't want the attention. I do have to say that my head is on a swivel when I go for test rides on the street. I grew up on dirtbikes and love them still, hence the look of my bike. Yours is coming along nicely by the way. You should also look at complete plastic kits on ebay for pitbikes, they're like $20 and the side panels will lock in to the rear fender.

So I made some progress today as far as the throttle is concerned. I got the throttle adapter mounted inside of the battery box and made up a quick adapter plug for the sabvoton using the connector from the old throttle. The pitbike throttle isn't the smoothest, but it works pretty nice. I added some moly grease to the end of the cable as well as the plastic internal pieces. This whole mod was very easy to do and I'd recommend it to anyone who doesn't want to mess with the hall throttles.
NOTE: This is 99% done. I think the cable is slightly too short because when I slightly hit the throttle is doesn't return all the way and you hear a faint hum coming from the controller. If I turn the wheel of the adapter a bit I can get the throttle to go back to zero. When I'm riding I don't notice this, especially because it goes away if you hit the brake. I'll try and tweak it later to get it to work flawlessly. For now I'm very happy with the results.

I went for a quick ride today and decide to take the gopro with me. The bike is so silent in the video, I love it. I was on power setting 3 in the video, let me know what you think.

https://youtu.be/7Zi3qFBnUwQ

@ shortcircuit911 , Your build is coming along nicely, now just to get my parts hopefully.

For anyone building these types of ebike that can do 25 + mph , its important to remember to control your speeds when you are in areas that can create problems. My ebike can do around 60mph top speed , but I programmed it down to 45 mph top speed, and even then, I rarely use it . I have found that 18 mph is a great cruising speed and it keeps you out of the focus of law enforcement . Its nice to have the extra speed/ power when you need it, but I try my best to only use it when it wont be noticed by onlookers.

Of course if you are fully registered/ insured and tagged for your ebike, then using it more as a motorcycle is more acceptable.

Hello. Also bought such a frame on Alibaba. And I have a question what are the dampers used? What size and model? Best regards

@krasak84 The forks I have on my bike were purchased from the same vendor that sold me the frame, I wouldn't recommend them. Instead I'd go with something like the one below. That is actually what I plan to buy next for my bike.
https://www.ebay.com/itm/Exclusive-DNM-USD-8S-Triple-Crown-Downhill-Air-Fork-203mm-20mm-Axle-Dual-Brake/332042526611?_trkparms=aid%3D111001%26algo%3DREC.SEED%26ao%3D1%26asc%3D20160908131621%26meid%3D7bfc44b3e5e64980afb1de5ccc5ce0fb%26pid%3D100678%26rk%3D1%26rkt%3D15%26sd%3D332042526611%26itm%3D332042526611&_trksid=p2481888.c100678.m3607&_trkparms=pageci%3Abe193a75-d68c-11e8-9e80-74dbd180f731%7Cparentrq%3A9f9b821d1660ad79101df884fff5a4f8%7Ciid%3A1

rear is an RCP2 which is also made by zoom, its pretty good. I believe it is the 200mm version, hope that helps.

So it finally came today boys, the QS205 is here! I was able to get it un-boxed and setup mechanically on the bike (dry fit) before taking the wheels in to the bike shop tomorrow. The quality of this motor is so much nicer than the piece of shit that was powering my bike. In the pic below you can see the size difference in the phase wires alone, 350 phase amps should flow nicely through them. Looking at the wires dropping through the swingarm and the rotor bolt clearance, and I think it'll be ok. The heads of the bolts touch the sheath covering the wires, but doesn't seem to be doing more than grazing it. I will be sure to zip tie it securely out of the way to avoid big problems in the future. I also had to drill and tap M6 holes in the swingarm for the new torque arms that came with the motor. Everything is looking good, just need to get the meat and freewheel swapped over to the new wheel. If all goes well I'll be riding by the end of the week which is good because there's a big ass dirt hill by my house I want to try and climb. More video to come.

Thank you. Helped me a lot. Yesterday it came to me this nicely frame. And I'm starting to complete slowly. Yours is very cool I like it. Thanks and good luck in the further construction. Best regards.

Congrats on your 205! I did order a complete plastic kit. Front fender fits forks well but is just too darn small, bummer!

@Gstegman Thanks! Proud owner here lol. Sucks about the front fender. How do the side panels look?

Well I got the wheels back from the bike shop, but had a nice chat with the owner before I left. He pointed out the there was a size difference in the shoulder/axle length in both hubs. I was planning on swapping the 7 speed cassette over since I had it, but decided to go with a 16T BMX freewheel instead. I didn't want to run into any clearance issues when mounting the motor. Man what a good call that was!

Mounting the motor:

When I got home I mounted the rotor, and mounted the wheel, and it had just enough clearance on the sprocket side to leave out the spacing washer I had before. doing this allowed me to shift the axle towards the crank side of the bike creating a bit more room for the massive wiring harness that comes out of the QS motor. I do need to get another chain because the pitch of the BMX freewheel is different than the pitch of the cassette, so now I have to figure that out, because the front sprocket is pressed to the crank (not bolted), so I might have to get another crank and sprocket, we'll see.

1st ride:

I took it out to this trail with closed off roads by my house and ripped! It got a little scary a few times as the rear end felt like it was starting to fish tail (speed wobbles). I also want to run a gps app next to what the tft screen is saying, because it feels like I'm going way faster than the speedometer is saying. I'll have to look into that soon, got bigger fish to fry.

Performance:

1st test ride was done on 250 phase amps and 100 battery amps. It was pretty good on the low end, I came back home and turned the phase amps up to 350A and that was much better. Still no wheelies though, so I was a little disappointed. I think the battery amps need to go up to like 150A to see wheelies, which isn't cool with my BMS, Bummer. All that aside, this thing is fun to ride and it pulls pretty nicely in complete silence. I did notice that the motor is a little coggy at low speeds, it almost feels like I have a bunch of tire sealant in one area of the tire and it has a prevelant thud every rotation, its weird. It goes away if you get back on the throttle, its only when coasting. When I got home I checked motor temp and the outside was 104F, which surprised the hell out of me. My other motor would make funny noised on accel when motor temp was 100 (outside of hub), so I put the fan on it so that it could cool quickly. The motor wasn't scorching hot, but it was definitely warmer than I thought it was going to be. I'll have to get some hubsinks on order.

TEST RIDE VIDEO:

https://youtu.be/XlyGICtRJ0A