E-Bike XB-502 conversion project

I bought some replacement shocks for the scooter. They arrived yesterday. Today I attempted to install them. They are a bit longer than the factory shocks, but I was able to adjust them down to the same length. However the springs are far stronger than the factory ones and the diameter is too large to fit. That's $90 worth of gas shocks I can't use on the XB-502.

I took apart one of the factory shocks. Once the spring was removed, the piston slides in and out with no resistance. Just about worthless. I'm looking for "other" shocks. grrr

I found a set of shocks...aka springs...that are stiffer and the right length on a junked moped I have. They are on the back of the XB-502 now. I'll see how they do, but any amount of greater stiffness will help to keep the back wheel from bottoming out.

Gas shocks are a bust so far for the back end. I did get some that will fit the front and will try them out on the front soon.

https://www.ebay.com/itm/235mm-Universal-Shocks-Absorber-Suspension-Fit-Kawasaki-Yamaha-Honda-Suziki-US/292758415671?ssPageName=STRK%3AMEBIDX%3AIT&_trksid=p2057872.m2749.l2649

Damn shame you could stiffen it up and look smart same time, couldn't you weld new tabs on to pick up the shock I've had a look at the pics but it's difficult to see, is your issue the shock is wider so it strikes the wheel and needs to be spaced out a bit ?

Won't be long this be running tidy, can you get air through the faring down a duct at the motor or a scoop underneath that pushes air into that area for a cold feed ?

Not many scooters get that treatment think how many of its brothers been ragged and smashed rare species here in UK.

This is the rear shock. It's about 30% stiffer than the originals and they fit. This was a big problem with my other attempts for rear shocks. The brake rotor, chaine and wheel sprocket were always interfering. At the bottom of the shock it's the same diameter as the originals. This keeps the shock clear of the rotor and sprocket. It has a bigger spring on it and slightly more travel. It's not gas filled...just a stiffer spring.



The front shocks were a near perfect fit. They are about 1cm longer than the factory ones. I had to drill out the bottom hole of the shock to 11.3mm, but otherwise they bolted right in. The factory front shocks were far too weak. Put on the brakes and the front wheel would plunge down and bottom out the shocks. I have the springs backed off all the way and no air inside the piston right now. I'll see how it rides before I start making it stiffer. This is already far more spring force than originally was on here.



I'll be working on completing the deck over the weekend. I need a second DC-DC converter. One isn't enough for my XHP70.2 head lights and everything else. I want to add a fan under the cowling for cooling the controller. Otherwise, it's done.

Ianhill said:

Damn shame you could stiffen it up and look smart same time, couldn't you weld new tabs on to pick up the shock I've had a look at the pics but it's difficult to see, is your issue the shock is wider so it strikes the wheel and needs to be spaced out a bit ?

Won't be long this be running tidy, can you get air through the faring down a duct at the motor or a scoop underneath that pushes air into that area for a cold feed ?

Not many scooters get that treatment think how many of its brothers been ragged and smashed rare species here in UK.

Click to expand...

This is the fasted electric moped I've seen anywhere. Getting air into the motor is no problem. It has a radial fan on it and the end plates are opened up. The controller might get enough air flow with a scoop, but without it sticking out somewhere, there's no good place to put it where it's in air flow. I'm probably stuck with fans. It's in an entirely dead air space up under the seat.

I thought about offsetting the rear shocks somehow so they don't interfere, but in the end they really need to be centered over the swing arms as much as possible. Also that area of the swing arms does not have a lot of room to add anything extra. I pretty much need to use the factory mount points.

Hopefully the weather will be nice tomorrow. We've had snow and cold for the past week here. I'd like to give it a ride with the new suspension in place.

Squeezing the front brake, the front shocks still compress, but not like before where any amount of force would bottom them out. I'll probably add a little air to improve damping, but they are already lots better. I'll put a little bike pump in the seat compartment so I can add air to the front shocks if I need it. The real test is riding around and putting on the brakes to see if the front end still plunges badly or not.

Plopping down on the seat with the original back shocks would nearly bottom them out. Go up a curb and the back shocks would bottom out and then launch you into the air. They give a lot less now...which is good...still wish I could have used those air shocks! I might have a way to pull that off. The front shocks are designed a bit differently than the backs. I may be able to use the ends from the old front shocks on the gas shocks to create some offset so they clear the rotor and chain.

What's the controller your using them nuclear ones you got are a nice bit of kit the 12f be beast on this ride, you get there in the end hope you can get them shocks on with the part of the front fingers crossed.

Putting it all back together, I found I needed to move the controller a little to clear the motor. The new rear shocks are slightly longer and that brought the motor too close to the controller so they would hit if the shocks were fully extended. I then discovered the controller no longer cleared the bottom of the storage compartment. So I had to cut out a long slot in the bottom. I'll close this up with some aluminum later. I lost the corner of the compartment...not much space really.





Since the shocks are longer, the back wheel no longer cleared when on the stand. I removed the old metal pads on the bottoms and then cut some teak wood to fit over the round ends. There's a teak dowel inside both tube ends that's several inches long and hammered in. To get them back out would need drilling and fire to burn them out. The center is tapped with 1/4-20 threads so the teak feet can be held in place with a bolt. The feet are also glued to the tubes. There's lots of support here now. They won't be going anywhere and teak is pretty well indestructible. If WW2 battleship decks could be made of teak and hold up to that grinding environment, it will work well for extension feet too! This got me 1" under the back wheel. With the original set up, I had maybe 1/2" of clearance under the back tire. Now that I have longer back springs, I'll look for gas shocks in this size. I might get lucky!

The test ride was compelling. The front end in hard braking was perfect. No diving hardly at all and the damping was a huge improvement over the springs. The ride in the front was significantly better on all counts. The rear still has springs on it. Albeit stiffer ones so that made the back end feel more solid, but there's no damping at all so bumping over curb still launches you off the seat. I could not bottom out the rear springs anymore. The fact that it now stands an inch taller in the back was not noticeable at all.

I didn't get far and I stopped to tweak the phase amps. I've been running at 130 amps and just bumped that to 160 a few minutes before I ran out of juice. I haven't charged since my last ride so I had very little capacity left. 160 amps was a good bit stronger. I've never looked for the sweet spot in phase amps and more or less arbitrarily set it to 130.

The controller was running at 110F and the motor at 95F in 40F weather. I'll need to add a fan under there for the controller. It can't get any air flow at all.

That brings me to the last item. The BMS. I upgraded a smart BMS a while back for this EV. That's working perfectly in place of the dumb BMS I originally had in it. I'm charging now and seeing actual pack status is great.

BTW, there's a new feature in the PowerVelocity app. It now "talks" directly to several smart BMS's so you see pack status too...including this one. There's some bugs to work out yet so readings can be squirly sometimes, but it does connect to smart BMS's and usually displays BMS status. All this stuff can display correctly, but then there's some bug in there still that makes it get the data wrong sometimes. This functionality is just days old now.

The more or less final dashboard.



I enlarged the long hole in the bottom of the storage space some and then made this piece of aluminum to cover the opening. I didn't really lose very much space. It's held down with a bunch of small screws and then sealed with silicon. The controller just clears now.

ElectricGod said:

BTW, there's a new feature in the PowerVelocity app. It now "talks" directly to several smart BMS's so you see pack status too...including this one. There's some bugs to work out yet so readings can be squirrelly sometimes, but it does connect to smart BMS's and usually displays BMS status.

Click to expand...

• Is there a list of BMS's that work with the new PV app?

• And does a BMS have to be "smart" in order to work?

M

MJSfoto1956 said:

ElectricGod said:

BTW, there's a new feature in the PowerVelocity app. It now "talks" directly to several smart BMS's so you see pack status too...including this one. There's some bugs to work out yet so readings can be squirrelly sometimes, but it does connect to smart BMS's and usually displays BMS status.

Click to expand...

• Is there a list of BMS's that work with the new PV app?

• And does a BMS have to be "smart" in order to work?

M

Click to expand...

List...I can tell you which ones work right now, but that's going to change. There's a few more we want to support.

On AliExpress, the seller ICGOGOGO lists a variety of smart BMS's. They are pretty popular and decently designed. This is the BMS's we are supporting in the app. No "dumb" BMS's will every be supported. They are categorically dumb and won't ever have enough "brain power" to be useful in the app.

After yesterdays test run, I knew I needed to make a few small changes. I was running at 160 phase amps and seeing controller temps in the 115F range. The controller is up inside a hole with minimal air flow. Today, I added a blower to push air across the controller. The piece of aluminum deflects air downward and across the larger heat sink fins more. I nearly immediately saw the controller was not warming up like yesterday. I suspected I could get a lot more out of the motor, so I bumped to 180 phase amps and controller temps stayed around 90F. After a few miles of riding hard, I went to 200 phase amps and peaked at 100F. Motor torque was a lot better and that of course means better acceleration.The dashboard image is a minute or so after stopping. I'm pretty happy with motor torque, but may try for more if temps stay down. I may drop a tooth on the motor sprocket too and see what happens.

So far I have been stress testing. Now to find out what kind of range I can get.

ElectricGod said:

ist...I can tell you which ones work right now, but that's going to change. There's a few more we want to support.

On AliExpress, the seller ICGOGOGO lists a variety of smart BMS's. They are pretty popular and decently designed. This is the BMS's we are supporting in the app.

Click to expand...

Hmmm... these seem quite similar (I'm looking for 150A 20s): http://www.eastgem.net/bms.html

Thoughts?

Michael

Ianhill said:

What's the controller your using them nuclear ones you got are a nice bit of kit the 12f be beast on this ride, you get there in the end hope you can get them shocks on with the part of the front fingers crossed.

Click to expand...

I'm using a somewhat modified PV 18 fet. The Nucular 12 fet isn't strong enough for this build.

MJSfoto1956 said:

ElectricGod said:

ist...I can tell you which ones work right now, but that's going to change. There's a few more we want to support.

On AliExpress, the seller ICGOGOGO lists a variety of smart BMS's. They are pretty popular and decently designed. This is the BMS's we are supporting in the app.

Click to expand...

Hmmm... these seem quite similar (I'm looking for 150A 20s): http://www.eastgem.net/bms.html

Thoughts?

Michael

Click to expand...

Yes...that's one that is supported and IS listed by the ICGOGOGO seller

The DC-DC I have in here now is too weak. Run the XHK70.2 headlights and they pull down the current. The whole 12v electrical system sags. I was going to add a second DC-DC in parallel of the same kind. Its output is fully isolated. I have been unable to find them again. Instead I had a couple of cheap DC-DC's and decided to upgrade one of them. Originally, it could do 15 amps max and that for just 30 seconds. I know because I have 2 of them and tried to run one at 15 amps. It burned out. The second one, I rewound the inductor and installed a HY5110 TO-247 mosfet in place of the factory Chinesium mosfet. I also beefed up a few traces. Now it handles 16 amps continuous no problem. I ran it at 16 amps for 30 minutes. I needed a larger heat sink and since the board is now exposed, I coated it both sides in conformal.


The un-modded one is on the left. See that zig-zag trace on the board? That's the fuse. LOL! When I later blew up this DC-DC, that trace burned out, but not before the mosfet died and took out all the small electronics too. I bypassed that fuse trace and added a 15 amp fuse to the output. The traces to the mosfet all got beefed up.



The inductor is 30 turns on this core to get 9 uH. Originally it had 20 awg on it. I rewound it with 14 awg. Before the stock DC-DC died, I put my finger on the inductor. It was HOT running at 12 amps. Now 30 minutes later at 16 amps and it's not even warm. The right most component is the HY5110 mosfet. The part to it's left is a back to back diode. I originally swapped that out too, but then went back to the. factory diode. Mine is a slow switcher and would heat up from the high frequencies in the DC-DC. The factory diode is a high speed switcher and was more than capable of handling the current so I went back to it.



This is the final configuration, but on a random heat sink. I later went a little larger one.



Mounted and getting wired up. Way up underneath the cowling like this air flow is minimal. I may not keep it here. One I pull the other one out, that spot is free and far better for air flow.

Since I had the cowlings apart to get the old DC-DC out, I decided the new one would go in the same place. Ironically, it's 1/2 as large and almost double the amperage. When I run my XHP headlights, 12 volts dips to 11.7v, but not to 10.5v like the other DC-DC did. I also discovered that everything on, I'm pulling 9 amps...which is about all the old DC-DC can handle. The new one is being used at 1/2 it's capabilities so it has lots of potential left if needed.

I know this looks like a bad idea, an exposed circuit board in the weather. It is thoroughly coated in many layers of conformal on all surfaces. You could drown it in water and nothing would happen. I did make one change to the DC-DC. I replaced the 100uF, 150v input cap with a 470uF, 100v cap to clean up power a bit more. The original cap was getting hot anyway and would not have lasted very long. I already replaced the output cap with a 3300uF cap instead of the cheap 2200uF that was in there.

I finished the deck last night and sealed up the battery box. I still should make some fillers to match up to the side panels, but that's a small detail.



Now that I have the new DC-DC in place I thought I'd see how much better the dual XHP70.2 high beams are than the Chinese low beam LED lights.

This is the low beams. Typical Chinese LED's...very blue light. The image is very grainy due to the low light conditions.





High beams...the camera took a much better picture with lots less graininess. It doesn't look at like it in the image, but this is 2-3X brighter.





Just the running lights in the dark.

I think this is done. Maybe if something comes up I'll do something more, but I'm pretty sure it's not getting better than this. Time for a BIGGER project such as the RMartin!

Running lights, low beams and high beams.







A few images of the finished build.

I haven't had the chance to try out the headlights in a long while. The low beams light things up, but they are pretty useless at lighting up the road. The XHP70's however, they throw a nice beam in front of the scooter. I want to adjust them up a little. The light is a little too close in front of the scooter.

Torque is pretty good up to about 52-53mph and then acceleration is petering off. Getting to 50 happens pretty quickly. Getting to 60 takes about the same amount of time. I did a test run for speed tonight. I was still accelerating when I ran out of road. Still not too shabby...57.7mph on level road.

50-60mph is the upper limit of the roads it's suitable for so it's bang on in my view not to overkill just rite for a commuter.
Good luck on your projects hope to see something mad soon with all these parts you got, I'm making progress on my stand-up.
https://endless-sphere.com/forums/viewtopic.php?f=35&t=97557

Well it figures...I think I'm done and then decide I'm not.

The headlight switches can't handle the current of the headlights. They are already getting wonky. I Put together a couple of mosfet switches and started wiring them in place. I soon discovered that I had left the electrical system in a semi kluged state from what the factory did. It didn't take long before I was pulling out all the wiring and setting it up for common ground instead of the mix it is now.

so much for done! 5 steps backwards to fix the headlights.

Ianhill said:

50-60mph is the upper limit of the roads it's suitable for so it's bang on in my view not to overkill just rite for a commuter.
Good luck on your projects hope to see something mad soon with all these parts you got, I'm making progress on my stand-up.
https://endless-sphere.com/forums/viewtopic.php?f=35&t=97557

Click to expand...

Yes...I agree..it doesn't need to be faster and realistically it's pretty damn good as is.