Another Stealth bomber (clone) build

[Dung]

Hi shortcircuit911

It's been long time since and I feel sorry for what happen to your bike and hope you will be back with your bike. I ordred the DNM USD 8 for ½ years ago at EM3EV but didnt have time to assemble it. Now I'm starting to assemble the forks on it, but it looks so wrong. Just checked it again and yes 2 different tube size. Mine has this tube size https://www.amazon.com/DNM-USD-8-Downhill-Mountain-Taper/dp/B01BIQN1LY

and at the EM3EV : https://em3ev.com/shop/dnm-usd-8-front-fork-black-latest-version-dual-disc/

Some more pictures:

Can I change the tube?

This guy also bought his forks at EM3EV. https://endless-sphere.com/forums/viewtopic.php?f=6&t=99526

 

[markz]

You can get adapters to make taper fork tube fit on your bicycles headtube. It changes the dynamics of the fork, making the front a tad taller.

 

[ossivirt]

Hi shortcircuit911

It's been long time since and I feel sorry for what happen to your bike and hope you will be back with your bike. I ordred the DNM USD 8 for ½ years ago at EM3EV but didnt have time to assemble it. Now I'm starting to assemble the forks on it, but it looks so wrong. Just checked it again and yes 2 different tube size. Mine has this tube size https://www.amazon.com/DNM-USD-8-Downhill-Mountain-Taper/dp/B01BIQN1LY

and at the EM3EV : https://em3ev.com/shop/dnm-usd-8-front-fork-black-latest-version-dual-disc/


Some more pictures:

Can I change the tube?

This guy also bought his forks at EM3EV. https://endless-sphere.com/forums/viewtopic.php?f=6&t=99526

Seems like you have that "Electric enduro" frame. It comes with hardware to install normal style or tapered forks. At least mine did Come with both.

 

[Dung]

I just wonder why they we have 2 tube version of that forks. But in their website under the Description it says: Steerer tube： 28.6 mm (1.13 inch) AL-7075. Now they have chinese new year have to wait 2 weeks more to contact them, how they can help me.

 

[shortcircuit911]

Dung good luck with it all, let us know how it goes.

Well I took my kid riding this past weekend. We took the razor and burromax along with my cr125. Had a super fun time and probably the last time I'll ride the cr with a gas motor. More on that later.

I also just got the wheel back from the bike shop which looks pretty sweet! I quickly mocked it up on the bike and see a bunch of little tweaks I need to do. I'm going to start chipping away at it and see what I can come up with. I'm pretty close to being blocked by not having the motor. I'm a little over half way there budgeting money for the motor and chain from lightning rod's. Here's some pics, be back with more.

 

[John in CR]

With the kind of riding you guys are doing, to gotta mount hubmotor flats vertically for more strength, and never ignore the obvious sounds of play in the axle during regen. A more modern controller with variable regen will help too, so you don't get that initial big hit on the system when you engage regen.

On the build immediately above, how about a drawing on the pic of where you plan to mount the mid-motor? It sure looks like you're short on space, and below the swingarm seems like it will have clearance issues based on the pic a few pages back landing a jump and the suspension going to full or almost full compression.

 

[shortcircuit911]

Hey John, that's a damn good idea, wish I thought of that. I've seen a few swingarms on here (vector maybe) that have vertical slots, those guys will probably have much better luck.

So as far as the build, the current plan is to get the big block and mount it under the swingarm. I would love to mount the motor on top of the swingarm, or like the cyclone kit so that there is more ground clearance, but that's a lot of work (not out of the question though). I'd like to ride the bike with the motor on the bottom and see how annoying it is. If I can live with it I'll leave it, if not I'll either make another swingarm, or build another bike from scratch. Sometimes it's easier to just start over.

Still collecting cans for that big block, hopefully soon.

 

[John in CR]

"Big Block" always makes me laugh when I see it here on ES, so thanks for my chuckle of the day. I'll have a mid-drive ebike rolling within 2 months as long as the coronavirus doesn't reach up a bite me regarding a part absolutely necessary to the build. If those little outrunners are Big Blocks, mine will have a more silent and far higher power Gargantuan Block. I have motors and batteries, and just got my dual Thermo Nucular 24Fs Monday, so it shouldn't impact me, but who knows. I went to the pharmacy today to pick up medicine that is manufactured in this country, and was told it would be 2-3 months before they get any in due to the virus. Apparently one of the ingredients comes from China. My other 6 Nucular 12F's are also delayed due to the virus despite being designed and built in Russia. They use some Chinese parts too.

 

[efMX Trials Electric Freeride]

"hub monster" always makes me chuckle lol.. and ppl dieing inconveniences my bike parts :?

 

[shortcircuit911]

John glad you got a chuckle, don't die and post a video of the build. Didn't know we were competing but I'd be happy to race in an off-road setting, let me know if you're ever in Cali.


@efMX that second line lmao, thanks for the chuckle :lol:

Luckily the parts I need to get my bike going are just up in Oregon, only a matter of cash and some more fab work for me.

I changed my mind yet again and decided to ditch the bmx freewheel and put the drive sprocket on the right side to clean things up. There were some clearance issues that I didn't want to deal with so I decided to go with this configuration. I'll like;y end up making another swingarm (something like the emoto) if the ride is unbearable. I'll likely keep the pedals and ghost pedal if I'm at the mtb trails or on the street. I'm cutting and machining the last few pieces to button up the rear, this includes a caliper mount, chain adjusters, and finish welding everything up before powdercoating. Like John, I'm probably 2-3 months away from getting this thing back in the dirt.

 

[Muney]

any progress on this ? to me it looks like the motor will be hitting the front of the rear tire?
an exciting build if you can pull this off..this motor QS 138 is a beast !
am wondering out aloud here, are there longer swing arms available for this frame?? it might be the solution
gday there mate,
was thinking to myself today , wouldnt it be great to have a mid motor QS 138 on a light weight frame like an enduro, similiar to how LMX and others do it..and voila came across your thread..
love the work, im gonna have to scroll back to the very first page and slowly build your build thread..
any chance i can speak to you on messenger or fb to try keep in touch with you real time?
gday there mate,
was thinking to myself today , wouldnt it be great to have a mid motor QS 138 on a light weight frame like an enduro, similiar to how LMX and others do it..and voila came across your thread..
love the work, im gonna have to scroll back to the very first page and slowly build your build thread..
any chance i can speak to you on messenger or fb to try keep in touch with you real time?

 

[shortcircuit911]

Hey Muney, not much progress other than saving some money every paycheck for the new motor. I'm not sure if you saw above, but I've abandoned the idea of the qs138 motor because it's simply too large. The new plan is to go with Lightning Rod's new ipm big block. The last 2 things I need are the motor kit and chain which I hope to have within the next month or so. The big block paired with my mobipus controller should make this thing rip! I've been dying to ride lately so I've been putting lots of time into my razor mx350 (lipo pack, brushless setup, gearing) because it's a waiting game for the eeb at this point.

Stay safe out there everyone, cray times.

 

[Dung]

*Update*

EM3EV dont want to help me, because its been ½ year since i bought at them. Super great service. I choose them and willing to pay extra because I dont want that kind og headache. Now I got it. I took my fork to local bikeshop to try out an adapter for tapered fork into straight tube. Doesnt fit, then I mail to DNM. They said I just need to change the lower crown and the 1 1/8" steering tube, it cost only 25 $ but the shipping cost is 111 $. I end up to buy new DNM USD8 fork from Aliepress. Now I can almost build 1 more bike.

 

[shortcircuit911]

Dung, thanks for the update. Glad you made progress, sorry to hear how it went though. Good luck with it all and be sure to post some pics on the forum.

So it's been too long, but finally I've made some progress worth posting. The big block finally showed up today and it's a beaut. Mike (Lightning Rod's) was easy to deal with and the parts were top notch. I also picked up some 219 kart chain from him so it's time to get to work. A few posts ago John mentioned the motor would sit low and yeah, it's definitely a low hanger. No worries I knew that going into this, so it's time to start the new swingarm build after I install the motor to the current one so I can put some miles on it. The new swingarm will draw lots of inspiration from the open emoto swingarm with a few twists to fit the eeb.

I made a video showing some of the parts and gave an update on the current state of the bike.

That's here: https://youtu.be/YRUfHdF1LwU

As always, so much more to come!

 

[shortcircuit911]

Well I've been thinking a lot about how I want to mount the motor and have come up with a new orientation. There are some pros and cons to the new mock up,so I would love to hear some feedback. The pros I see here are obviously more ground clearance than mounting it under the swingarm. The next pro is that the drive sprocket is closer to the pivot point of the swingarm. I really like how the motor seems to fit nicely in that area and provides a better overall look. However, there are a couple things I'm not thrilled with, the first it the length of the chain. It's definitely longer than I'd like, but not a deal breaker. The length is actually about the same length (drive sprocket to rear axle) as my cr125. I thought I remember reading somewhere that it's better to have the drive sprocket above the pivot point of the swingarm, but can't remember.
Anyway I think this is what I'm going with unless someone chimes in and points out some flaws that I'm completely missing (I'm no engineer). I'm also going to start working on getting the motor to spin as the mobipus will need a new profile flashed for the IPM motor. Since the chain is so long I had to order a couple more just to have enough in the new orientation, that should arrive next week. With the shelter in place in effect I'm only going to the shop once a week so I'm trying to get as much worked out at home so when I go in I can do a bunch of fab. I hope to have the swingarm completely welded up (the rear is only tacked) next week and possibly go for a test ride if all goes well.

 

[ossivirt]

I think its better option than under swingarm but I also am not an engineer. I have been watching your progress and it seems like you are skilled fabricator so I would like to point out one other possible way to do it. Mout the motor "inside" swingarm or kinda build your swingarm around the motor so that suspension bracket is just above motor and rest of the swingarm goes under and over the motor. You will get better ground clearance and shorter chainline but it means a lot of work to do it. But you can do it :wink:

 

[efMX Trials Electric Freeride]

the pictures with the chain, looks like may have chain crank/ peg clearance as the suspension cycles??

 

[shortcircuit911]

ossivirt, thanks for the kind words, and yes I am a fabricator. The option to have the motor in the swingarm is the best option in my opinion. Making another swingarm isn't off the table. The plan is to mount the motor to this swingarm and likely make another. In the process of mounting the motor under the swingarm I was just exploring other options and came up with the current one.

efMX yeah the chain runs inline with the pedals so I need to get creative there. One thing I'm exploring is putting a one way bearing on the shaft the cranks bolt to and mounting a 219 sprocket to the bearing. Doing this will keep the bike "looking" legal and would be a really shitty way to pedal home if I had to. I was also planning on adding an extension to the shaft the crank arms bolt to so that there's virtually no change to the pedals/pegs. The chain will definitely need a spring loaded roller that keeps the chain tight as the suspension cycles, but thus far it seems like it's going to work. I took some pics to try and convey what I'm talking about.

Here is a link to something similar I'm considering:
https://www.quartermasterusa.com/product/drive-sprocket-219-conventional


Awesome feedback! Keep it coming.

 

[shortcircuit911]

Made some progress on mounting the motor. I was able to do most of the machining and fabrication to mock up the motor, but it is all only tack welded for final fitment. I'm hoping to be able to keep the pedals to look the part and the pic below shows how I hope to tackle the problem of the chain being in the way. I think it'll work, but need to confirm. I'm waiting on hardware, a spring loaded chain tensioner, and a bit more fab before I can line up the chain and make sure everything jives. When that is done I'll finish weld everything and test ride. I'll be in the shop again next week so I can likely knock it out then and hopefully going for a test ride soon after.

More coming

 

[shortcircuit911]

Made some more progress on the bike this past week. I've been putting in more hours working form home so spare time has been a bit more limited, especially with the family home as well.

In the past week I was able to get the motor mount fully welded and got the new mounting holes drilled out as well. The rear swingarm extensions are also fully welded now and are ready for abuse. I ended up MIG welding most of it to save time and to fill some of the gaps easier, only some places were TIG welded.

The chain is lined up and sounds pretty good. It was a rubbing a bit on the swingarm so I made a chain slider out of delrin and bolted it to the swingarm, much better. I also made a new roller that lives on the bottom bracket spindle. I machined it to resemble a pulley so that it acts as a roller and a guide for the chain, that seems to be working well. I ordered a chain tensioner and made a mount for it, but am unsure if I'll need it. I'm going to leave it off for now and see how the test ride goes to see if it's even necessary.

I flashed a new profile on the mobipus for this motor and will likely tweak it once I see how it performs. I spun it up on the bench and it sounded pretty good, spins smoothly. The controller is in FOC mode so I should be able to see full potential of the motor once all firmware tweaks are made.

I still need to get the crank arms mounted so I have somewhere to put my feet! Left side will be no change, but the right side is where the mods will need to happen. The chain roller I made takes up all the room that the crank arm needs to be mounted, so I need to extend the spindle. I plan on getting an M8X1 stud and threading it into the spindle where the crank arm normally mounts. I'll then cut a spindle off my parts bike and weld them together, that should suffice. I've also been thinking up a design for foot pegs. I want it so that I can swap pedals out for pegs (in 5 min or less) if I decide to go to a track or off road area and don't want pedals.

Next post should be test ride results and more progress. So close!

 

[mcclead2]

Just wondering what size wheels and tyres you guys are runnig?

Ii am looking at buying QS 205 laced into 19" x 1.6" moped rims, but don't know what motorcycle tyres will fit this size!

Would 2.5 fit onto the rim? I am planning on using my E Bike for commuting to/from work, so mainly tarmac roads about 30 mile round trip

 

[shortcircuit911]

mcclead, welcome to the forum. You can run a 2.5" wide tire on that rim, I've run a few different types. Right now I'm running a shinko 241 and it's 2.75" wide. I've also run a dunlop knobby (70/100-19), you can run just about any motorcycle tire that's 19". Hope that helps.

Well I was able to get the bike back together and got the controller flashed with the new profile. I'm waiting on some hardware to finish up the pedals and the pegs, so there is no where to put my right foot at the moment.

First thoughts on the new setup were positive. The bike is louder now which I knew would be the case, and I actually like the sound. The acceleration from a dead stop could be better, but it pulls pretty good especially is you're already moving. There are 3 different modes 80A/100A/150A for the phase current. Obviously the turbo profile is the most fun/has more acceleration, but the problem is I can get the outside of the motor up to 90F pretty easily in turbo mode. So now I need to find a way to keep the motor cooler longer while maintaining the performance I want. I have a few ideas for this, one is to change the rear sprocket from a 94t to 100t. The next thing I'll do is get a 1/4 turn throttle which should help me get to full throttle faster. Lastly, I'll probably add a fan to keep the motor cool. I'll also turn the phase amps down a bit to keep the temp down. I just ordered a temp sensor for the motor so I'll get that installed asap to avoid frying the motor.

Video: https://youtu.be/BaTDO_PJzg4

 

[shortcircuit911]

Made a bit of progress with it all, mainly in getting the pegs mounted which is so much better than the pedals! A bit of bad news with the build. I've come to the conclusion that the motor is just a little too small for my power needs. The motor performance isn't too bad, it's capable of putting out some good power (I pulled 9kW), but there isn't enough mass in the motor to keep it cool enough to keep riding at that pace. So I'm going to put it up for sale in the for sale section here on the forum. I think I'm going to go with the 2kW version of the QS mid drive motor, and then I think I'll be happy. It's kind of a bummer because the big block is the perfect fit for the bike. Not having a hub motor in the rear wheel has really made it more enjoyable to ride, almost like a real dirtbike. I made a quick video with the motor in action for anyone that is interested in seeing it. PM me if you're interested in buying the big block.

Back with more.

Video: https://youtu.be/QTtjv-M6AIo

 

[shortcircuit911]

Well got the Big Block sold, on to the next one. 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.

 

[shortcircuit911]

Well the motor has just arrived which was lightning fast. I immediately hooked it up to the Mobipus for an rpm test. I was able to get it to spin over 4,600 rpm which is what QS is advertising. Just spinning it on the stand you can tell this motor is an absolute beast, I really can't wait to get it mounted. I just ordered the custom 84t rear sprocket from sprocket specialist which should be here next week. I also ordered 2 428 chains which should be here next week as well. I'm in the process of drawing up the motor mount in solidworks which will be laser cut and welded by myself. Everything is starting to come together, a test ride next weekend would be amazing, we'll see how it goes. More coming.