MAC broken by Local Bike Shop, ned advice

[johnxsi]

I've clocked up a 1000kms commuting on my Cellman Mac kit, and have been having a blast, but hit disaster a few weeks ago.

I broke a spoke, and took it to the local bike shop. While they were fixing this, they added a spacer between the motor and the cassette. When removing the cassette they forgot it was an electric motor and ended up twisted the entire wiring harness off the hub.

They took it to a nearby e-bike shop who supposedly repaired it, but after plugging it back in it's dead. I hear a high pitched whine but no movement whatsoever. The motor freewheels one way, but cogs(?a steppy, stuttery feel) when turning, but I don't know what that's indicative of.

Basically I need advice on how to proceed. I can take it back to the shop, but I don't know if I trust them to fix it. I'm also looking for a place that's familiar with repairing these kinda motors. Any thoughts?

Thanks!

 

[wesnewell]

Don't know about the laws in Canada, but here, you usually must give the shop a shot at fixing it before taking it elsewhere. If you're concerned with the cost, I'd take it back to them until they got it right or offered to compensate you towards the cost of a new motor. If they tell you to screw off, then the courts is your only option if you wish to recoup your losses. BTW, unless the nipple was lost on the broken spoke, there's absolutely no reason a new spoke couldn't have been installed without removing except the broken spoke. Done it several times on someone elses bike. I haven't broken a spoke since going to 12G ss spokes.

 

[teklektik]

They took it to a nearby e-bike shop who supposedly repaired it, but after plugging it back in it's dead.

I hear a high pitched whine but no movement whatsoever. The motor freewheels one way, but cogs(?a steppy, stuttery feel) when turning, but I don't know what that's indicative of.

Perhaps not the best terminology - it doesn't seem to be 'dead' - it's not inert, it's doing something... actually a good sign.

The free-wheeling and cogging sound more or less correct - it just seems to be running backwards - the wheel is not moving because the clutch is disengaged in that direction. My guess is that they messed up two of the phase or hall wires when they re-wired it. Try swapping any two phase wires to see if it runs forward. If that works, you will want to search down one of the many posts here about figuring out phase/hall sequences to ensure you don't have a 'false positive' forward wiring combination.

If it doesn't run, I recommend that you identify the actual problem yourself as a first step - this will take the mystery out of the negotiations if you decide to have the LBS bring it back to the motor shop -- or may encourage you to pursue the repair yourself. 'Time to repair' is likely a big consideration.

Search the forum for the simple steps to check the phase/hall wires for shorts and verify that the halls are okay. This is not difficult and you, the LBS, and the motor shop will have a better appraisal of the task at hand.

Ideally, if you are carting the wheel around by itself, you can tie-wrap the wiring to a captive torque arm to prevent it from twisting about. If there's no TA on that side, tightly clamp a small vise-grip to the axle flats on the wiring side and tie-wrap the wiring to that.

 

[cell_man]

It's more than likely some sort of damage on the phase or hall wires. It's not that difficult to swap a phase wire over. It only requires a soldering iron, a set of circlip pliers, some consumables and 1 or 2 hours of your time. If you follow up to about point 6 or 7 in the below link, that is the phase and axle already removed. It's easy enough to fit the standard phase wire into the axle (could re-use what you have), but if it's the upgrade version, that is more tricky to get into the axle and we use a slightly modded axle too.

Mac Stator Removal Procedure:
http://sdrv.ms/11eyBso

If you drop me a line with details, I'm sure we can fix you up with whatever parts you'll need to get it put right. Best not to try using it as is, there's the chance it could damage the controller. Drop me an email or a contact form, I will get back to you.

Thanks
Paul

 

[el_walto]

Why don't you try taking it to ebikes.ca. Maybe they will fix it for cheap, and get some of your future business.

 

[johnxsi]

Thanks all! I've got good leads on what to start checking so I'll be getting intimate with the Mac hub soon. (I did check with the eBikes.ca guys last week, but they're too busy at the moment.)

Ideally, if you are carting the wheel around by itself, you can tie-wrap the wiring to a captive torque arm to prevent it from twisting about. If there's no TA on that side, tightly clamp a small vise-grip to the axle flats on the wiring side and tie-wrap the wiring to that.

Very good idea, thanks tekletik.

If you drop me a line with details, I'm sure we can fix you up with whatever parts you'll need to get it put right. Best not to try using it as is, there's the chance it could damage the controller. Drop me an email or a contact form, I will get back to you.

Paul, cheers for the info, I will fire you an email.

Ironically I thought I went overkill with custom-double-1/4"-steel-dropouts to prevent this exact thing from happening, but here we are. :wink:

John

 

[teklektik]

Thanks all! I've got good leads on what to start checking so I'll be getting intimate with the Mac hub soon.

You may have run across posts for a controller/motor tester already, but here you go anyway.... cell_man has these as well and is a good add-on to any shipment from him. It's handy to re-wire with extended leads and connectors to match your build so you can just plug it in and diagnose issues in a few minutes. Here's a little doc on the gadget.

This well worth the investment so you have it in hand when you need it - which isn't the best time to start shopping for one - but you can certainly do the job with a DMM and a little extra time and care.

 

[johnxsi]

Cheers teklektic! One is ordered and en route. Meanwhile I have examined the hub and all wires look to be in the right place with nothing ripped out (thankfully). So the problem may lie in the axle somewhere.

I did a quick continuity check and when I test the edge of hub and the phase wires, 2 of them are connected. Am I correct in assuming that nothing should be touching the outer hub? Would that suggest a short in the axle?