Dead MP.

[Mabman]

I bought a 16" MP last fall. Right out of the box the thing would not work and I finally tracked it down to the moulded junction block between the motor and the battery/throttle wires. I made several requests to the main office for another cable but they were never honored. By zip tying the junction block to the frame I was able to get it to work for the most part but once in awhile I had to move it around a bit to get it to work again. Last spring it finally stopped for good and I put the project on the back burner. I am now wanting to revive it and am exploring my options.

After reading on here the problems with this models internal controller I was wondering if anyone has taken apart the MP and bypassed the internal controller and fit up an external one? I probably would not mind doing this if I am going to take the motor apart anyway as it seems I will at least have to in order to fit a new wiring harness if I could even get my hands on one of those.

Any help appreciated!

[MonkeyMagic]

Hey mabman
Have you got a cast 16" I love those haha

If the molded junction box is the culprit, just cut the cable before the mold and either hard wire it or make your own connectors.

An XLR plug & socket can do your power amongst many other heavy duty connections
You can use an 8-pin audio DIN plug & socket for your controller connections.

Total cost should be under or around $20

If you want to go hard out -->
Cost of new 8-pin power cable harness (controller to female 8pin) is $40USD and should come with another accessory 8 pin cable too. I ordered one and they gave me a 10AWG 1.2M power cable and a packet of circlips (the spring clip washers that hold the cable and freewheel etc. in place) oh yeah and it came with a spare freewheel too. I felt the price was worth it.

I would strongly suggest trying to re-wire before the molded plug because re-wiring the controller harness is an absolute bitch of a job and I do not wish it upon anyone haha. You won't have much fun making it external either, but if you really want to there is plenty of topics that have covered that if you do a search on the forum.

If you have the cast 16", IMO the internal controller had plenty of power to get it moving, mine pulled wheelies everywhere, and unless you put some serious volts through it you won't get it moving much faster with any other controller.

Good luck man !!

[Mabman]

Thanks MM. Will give it a try eliminating the junction block and hope that the internal controller is ok. And it is not a cast wheel as much as a MP with a 16" rim bolted directly to it and is a front wheel also btw. I have it mounted on a BOB trailer and it is a great rig for my needs as it doesn't clutter up my bike with alot of stuff. Only the throttle and some cable which I can disconnect easily. Plenty of torque but not much on the top speed but that is ok for my needs.

I did a search for the external conversion but didn't come up with anything I thought useful. Hopefully I can get it to work without getting in to it in that fashion. Thanks again!

[MonkeyMagic]

No fair Mabman!! I so want a bob with a MP wheel on it haha thats great

hope you get it working soon

[Mabman]

I have done many bike conversions, gas and electric, and always come back to the pusher trailer concept. I plan on doing one based on the xtrawheel trailer at some point with a 26" wheel.

[MonkeyMagic]

wow mabman sweet ride !!

does it slow you down at all?

[Mabman]

It is hard to get the bike to go much over 20 mph which is where the motor stops assisting so going downhill is restricted by the drag of the brushless motor. I average 18 mph and can get 40 miles out of a 12ah LiFePO4 battery that cuts out at 9.4ah and climb the steepest hills around here without a sweat which is what I like the most about it. I do pedal like 95% of the time in a high enough gear to get on top of the motor which certainly makes a big difference.

[MonkeyMagic]

Cool that was my thoughts exactly.

My cast wheel was only very short lived, I've since tried to power it up with an external controller as it has never lived again replacing the internal - and it makes an audible high pitched whine noise, and no movement - I can hear power going into the wheel and when I apply the throttle the EMF sound gets higher pitched. I have no clue whats wrong with it..  I'll try and pull it apart more.

Lol anyone know what that could mean?? It was a new motor.

Anyway - hope you sort yours out with the connector/cable setup... One thing on a rim that small I found was taking off the hub casing was a pain, hopefully you did this when you fitted the motor - if not you might need to bash the other side of the axle pretty hard until you get some movement on the other side of the hub casing (with the bolts removed of course)

Cheers

[GM Canada]

Living proof a cast 16 inch wheel fits on a bob trailor. Hmm I do have one of those in stock, but its also snowing outside. Maybe in the spring!

Gary

[MonkeyMagic]

hey yeah the front motor definitely would fit.
mabman was sneaky and bolted his motor to a 16" (BMX?) rim - I was always scared of damaging mine, but would be rare.

I think a front cast 16" and another  48v battery or 2 in the bottom of your Bob would go very nicely there Gary.

Just tell the wife you have been so good saving the world lately that you deserve it hehe

Oh - can the bob trailers fit a 20" wheel on there? or would that throw off the angle

[Mabman]

Actually the setup came direct from the factory with the rim already bolted on the motor.

It is a very tight fit in the BOB "fork" and I also had problems with the fact that the valve stem exited the rim on the right side which due to the offset for the disc brake made it hit the "fork". I have to have the wheel way back in the horizontal dropouts and so know for sure that a 20" wheel will not work. Not anything I would do again with the MP for sure but I do feel that a pusher is a great way to go and will be doing more with the concept as time goes on. I just want to get this one back in to working order at least for the time being.