Rad Wagon Rebuild Project

mikesova

Member
Hello all. A couple months ago I came across a RadWagon for sale on my local Facebook Marketplace. I have been buying and fixing up regular bikes during the Covid Pandemic as a hobby, so I was interested. I also have an Ejoe Koda e-bike that I really enjoy. Anyway, I went and checked out the bike. They were asking 200$. They said they bought it as a project and the previous owner said it needed a new battery. They never did anything with it. I decided to take a chance, since I figured there were more than 200$ worth of parts if I ended up not making it work. It has a suspension seat post which I see retails for like 80$, so there's that right there.

I got it home and started cleaning it up, it was really dirty and scuffed. I found that Magic Eraser sponges really cleaned up the scuffs.

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It was during the cleanup that I discovered the bent fork. I should have noticed it before, but it looks like it has been crashed and bent back a little. I know that bike shops have fork and frame truing jigs, so I'll look into that before looking at buying a new fork. I spun the wheel before purchasing and it was true, so those heavy duty spokes must really work.
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So, I also tried to charge the battery when i got home. The bike didn't come with a charger, but I already had one for my other ebike. The battery didn't seem to take a charge. I thought I would do a little investigating, though, the battery box is really broken and seems to have been modified so that the battery is directly wired to the pigtail that normally comes off of the battery holder. It was pretty easy to take apart since most of the screws were broken off. When I took it apart I found that a 5amp fuse was blown that was inline with the charging port. I put a 3a fuse in that I had laying around and boom it started charging. Cool!

After charging, it shows a full battery on the display, I also have a little meter that I hooked up and it showed it having 54ish volts. The battery may still be good. That would be sweet.
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The stock radpower controller and display gave me an error 30 message. I tried cleaning contacts, etc. but it wouldn't do anything. So I figured I should try a new controller. To buy a new controller from Rad is kind of expensive, and a company makes an upgraded controller that works with the display, but my display is kind of junky, so I figured I'd do a new controller + display, so I order a GD01 display along with a 30A controller that has the same motor harness as the one on the Radwagon.
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In the meantime, I replaced the fork, cables/housing, grips, and tires.

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I got the new display and controller the other day. I hooked them up so that the controller is connected to the battery, the motor, the display, and the throttle. I discovered that the brake plugs are different than those on the 1 to 5 wiring harness I got. The display will turn on, but when I turn the throttle, the motor doesn't move, but I hear a very slight click coming from the hub motor. There is also an "ERR" on the display. Any ideas?
 
I'd check resistance between the blue yellow green wires to the motor. About 1/2 to 3/4 ohms. Meters tend to read .6 ohms with the probes shorted so subtract that much from the reading.
My controller reads "err 02" when the motor wires are disconnected.
Motor bad, that's a whole lot cheaper than a bad battery. $200 for this might have been a bargain, if you wanted a cargo bike. The motor looks like DD anyway, which is not ideal for carrying loads. Geared hub is more the trick. I have mine on the front to balance the load of groceries in the pannier bags better. No power across ice, wet steel rock or wood, with a front hub motor. Fall down go boom! Pedal or walk on those surfaces. I've gone from 1000 watt Mac12t to 500 w bafang, and I'm really missing the torque at green lights to whip across 6 lanes before the light goes yellow.
 
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Nice project!
I don't know what kind of budget you're on for this project, but if you can swing it you would do well to replace that gutless direct drive motor with a MUCH peppier geared hub motor, even if it's only a 500 watt motor.
 
I'd really rather not invest much more into it. It was basically just a project for me. I don't really need it, although it would be a fun rig to ride to work. Is there anything I should be looking at in the motor that could possibly repaired?
 
Sorry, not familiar with your controller/display at all.

You have a 3 button switch for turning the bike on and selecting a PAS level? If so, there's generally a "walk" mode engaged when you press in and hold the "down" button. That circuit bypasses most of the safety stuff. It would be interesting to know what happens when you try that.
 
Sorry, not familiar with your controller/display at all.

You have a 3 button switch for turning the bike on and selecting a PAS level? If so, there's generally a "walk" mode engaged when you press in and hold the "down" button. That circuit bypasses most of the safety stuff. It would be interesting to know what happens when you try that.
Thanks, yeah, I didn't see much information about it, either, I guess I figured they were all basically different shades of the same thing, but that seems to not really be the case. I did made sure that the display is compatible with the controller I got.
 
i tried pressing and holding the - button, nothing happened. :(

If I were to take apart the hub motor, do you think there would be anything that would immediately scream : THIS IS WHAT IS WRONG ?
 
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I hung the bike from the ceiling. I turned on the display and spun the wheel while turning the throttle, it would power for a few seconds and stop. Does that help with a possible diagnosis?
 
You have an electrical problem. Such problems are usually repaired by replacing components. New components are often incompatible, such has having different plugs & sockets that can be bought separately only in quantities of 100000.
You can check that all 3 phase wires are continuous to each other with an ohmmeter. As suggested in post #2. You can check the hall effect sense wires to negative (black) are a coupla thousand ohms with an obsolete DVM. New modern DVM like the Klein I bought last year find everything electronic has resistance 9999, same as a broken wire, because the sense voltage is too low to read a diode drop.
If you don't need the bike, trash it. If you do need it, the DD motor was **** anyway for a bike that isn't run at 15-25 mph continuously on long commutes or bike paths. The DD motor was totally inappropriate for a bike carrying cargo that starts & stops at traffic lights & stop signs.
An entire 26" 48 v DD motor kit with matching components is $269 https://www.ebay.com/itm/194523759273?hash=item2d4a8502a9:g:RRoAAOSwS45hd3Xl
The motor that accelerates quickly from a stop and has high torque up hill with cargo is the geared hub motor.
Geared hub kits are now hard to find. Ebikeling is only selling 36 v geared hub kits, and you have a 48 v battery. Ebay has no geared hub kits at all. Euronau-ebike.com has motors and controllers but they don't say which ones are geared, the controllers are sold separately, and may not match the motor or the display or brake handles. The only euronau motor with geared in the description is a 36 v motor.
Batteryclearinghouse.com has bafang geared 36 v 26" wheel hub motors for $45 + freight. Used. The plug is incompatible with almost anything. I cut the plug off and installed a rectangular hall effect sense connector from ebay and .157" bullet connectors on the phase wires from OReillys auto supply.
Leafbike.com has a 26" 48v geared hub motor kit 500w with all the parts that match each other. $395 today. Almost all his listings are DD motors, however, don't be fooled.
I have no solution for your incompatible brake handle plugs except to buy a new controller with compatible plugs, or buy brake handles with compatible plugs for the controller you bought. Some brakes handles are normally closed so the controller won't work without the brake handles plugged in. There are at least 4 varieties of brake handle plugs, and they come with NC and NO switches both. Getting anything that matches is a ****shoot on ebay amazon or ali. Whole kits as the leaf solve the problem, but leave the wiring external tied on with ty-wraps.
 
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You have an electrical problem. Such problems are usually repaired by replacing components. New components are often incompatible, such has having different plugs & sockets that can be bought separately only in quantities of 100000.
You can check that all 3 phase wires are continuous to each other with an ohmmeter. As suggested in post #2. You can check the hall effect sense wires to negative (black) are a coupla thousand ohms with an obsolete DVM. New modern DVM like the Klein I bought last year find everything electronic has resistance 9999, same as a broken wire, because the sense voltage is too low to read a diode drop.
If you don't need the bike, trash it. If you do need it, the DD motor was **** anyway for a bike that isn't run at 15-25 mph continuously on long commutes or bike paths. The DD motor was totally inappropriate for a bike carrying cargo that starts & stops at traffic lights & stop signs.
An entire 26" 48 v DD motor kit with matching components is $269 https://www.ebay.com/itm/194523759273?hash=item2d4a8502a9:g:RRoAAOSwS45hd3Xl
The motor that accelerates quickly from a stop and has high torque up hill with cargo is the geared hub motor.
Geared hub kits are now hard to find. Ebikeling is only selling 36 v geared hub kits, and you have a 48 v battery. Ebay has no geared hub kits at all. Euronau-ebike.com has motors and controllers but they don't say which ones are geared, the controllers are sold separately, and may not match the motor or the display or brake handles. The only euronau motor with geared in the description is a 36 v motor.
Batteryclearinghouse.com has bafang geared 36 v 26" wheel hub motors for $45 + freight. Used. The plug is incompatible with almost anything. I cut the plug off and installed a rectangular hall effect sense connector from ebay and .157" bullet connectors on the phase wires from OReillys auto supply.
Leafbike.com has a 26" 48v geared hub motor kit 500w with all the parts that match each other. $395 today. Almost all his listings are DD motors, however, don't be fooled.
I have no solution for your incompatible brake handle plugs except to buy a new controller with compatible plugs, or buy brake handles with compatible plugs for the controller you bought. Some brakes handles are normally closed so the controller won't work without the brake handles plugged in. There are at least 4 varieties of brake handle plugs, and they come with NC and NO switches both. Getting anything that matches is a ****shoot on ebay amazon or ali. Whole kits as the leaf solve the problem, but leave the wiring external tied on with ty-wraps.
dang. gloomy.
 
Did you use a multimeter on both ends of all the connectors to make sure a cable didn't get messed up in the crash? Could be a brake switch broke in the crash and you have an open circuit. I feel you have to approach that bike as a crash rebuild since that fork took such a big hit. Often factory replacement parts are the thing to buy, despite the cost. I sure wouldn't keep throwing money at it, buying more parts. That's a very expensive way to troubleshoot.
 
Did you use a multimeter on both ends of all the connectors to make sure a cable didn't get messed up in the crash? Could be a brake switch broke in the crash and you have an open circuit. I feel you have to approach that bike as a crash rebuild since that fork took such a big hit. Often factory replacement parts are the thing to buy, despite the cost. I sure wouldn't keep throwing money at it, buying more parts. That's a very expensive way to troubleshoot.
I haven't. I am thinking I'm going to open up the wheel before I buy anything and just take a peek at the insides. I need a new multimeter, so I should probably grab one of those and try to diagnose it. Any guides or youtube videos on what I should do, that you would recommend?
 
When I hooked up the new controller and display, it had a new 5 into 1 cord, I didn't hook up the brakes. Would not having the brakes connected cause the issue I'm having? not trying to be an ask hole.
The brakes not being hooked up shouldn't have affected a thing. Don't worry about being an ask hole. Just hang in there and work as your understanding of what's going on here grows....
 
If I were to replace the hub motor, would this make a good replacement? It seems like as good a time as any to learn how to lace up a wheel. :)

Yes. That's a Bafang G020/SWX02 motor. I have two bikes with that motor. An Electra Townie and a Mongoose Envoy (shown) similar to the Rad Wagon.

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I assume your bike is a Radwagon 3? And would be compatible with a 135mm rear axle.

According to the Radwagon 3 specs I found, the rims are 36 hole so they should lace up nicely to the Bafang motor. I would get a motor-only kit including motor, brakes, cabling, controller, and display. If you do, make sure to get the cassette (DC) version of the motor which gives you a better choice of gearing.

For a 26" rim, the spokes to lace a SWX02 motor are close to 217 mm cassette side and 219 mm the other. But to be sure you should measure.

Roger Musson's wheel building book explains how

FreeSpoke is also helpful for calculating spoke lengths.

This kit on Amazon should work with your existing battery (assuming it's still good) and rear rim.
Bafang 500W motor kit - Cassette

Neat project. Good luck!
 
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