Replace axle in Go SwissDrive rear hub drive motor?

JRA

Well-Known Member
I have the same puller mentioned. Aside from the friction of the bearing race(s) on the bb spindle alot of what is holding the motor together is are the magnet/stator being attracted to each other and the need to break that bond. Should come apart easily with the puller.
 

bombadero

Member
That guy on the German YouTube channel responded; between his poor English and my lack of German, the communication isn't great, but he seems to suggest that once I take it apart, the change detected in the sensors will essentially brick it without re-calibration. My mechanic gave me access to the GSD service tool which will allow me to re-calibrate it, but I'm not sure if he's indicating some sort of special manufacturer's tool or a physical process. What's especially strange is that his videos are full of GSD motors taken apart.
 

bombadero

Member
Wow, well really frustrated with all of GSD, HP Velotechnik and my local distributor/mechanic at this point. After a shipping delay, HPV got the 3rd motor out. To be fair, breaking the axle on the second motor was my fault/an act of the torque-wrench-miscalibration gods. However, after installing this brand new motor, the same thing is occurring as before, namely that no assistance is coming from the motor at all, at any assist level. There are no new errors, as expected given that it is a new motor. I ran motor calibration through the service tool my mechanic provided, which completed successfully but did not fix the problem. The first motor definitely failed, it was throwing out error codes left and right. So at this point we are looking at either a) HPV sent me a defective replacement motor, which would beggar belief, or b) total system failure, as, if the motor is fine, then the computer and/or wiring harness must be to blame. I can't fault HPV for service, as they have been fairly responsive for being half way across the world. My mechanic hasn't been nearly as helpful as I would have hoped especially given that I am doing most of the actual work. GSD for their part has been outright unhelpful. At this point, I can't really recommend GSD at all, despite the general feeling that they made good drive systems, and I can't recommend HPV because it's so difficult to get timely service for their trikes in the US, irrespective of the fact that GSD liquidating is not their fault and they are already sourcing new drive systems for future trikes. Any e-bike is only as good as the service you can obtain for it. Moreover, I just feel that this system, for which I paid a premium, hasn't really justified the extra cost over a cheaper solution. When it runs, it's great. But a year in, with only a year warranty - which is kind of a crap warranty - I'm dead in the water and the drive manufacturer is being liquidated. If I had known any of this in advance, I would have gone the DIY route, but I'm invested at this point.
 

JRA

Well-Known Member
Kind of hard to press the like button for that tale of woe. Hopefully it will come together for you though!
 

bombadero

Member
I'm pleased to report having a little egg on my face, although I still can't recommend GSD, and only reluctantly recommend HPV to US buyers of trikes. Apparently the new motor was not providing any assistance because it was a static test - I had the rear wheel suspended with no load. This is normal - with no load, you shouldn't get any assistance. The mechanic got back to me and recommended a test ride after we came to this conclusion, and sure enough it rips again. I hadn't known this was the normal behavior, as previously the motor would kick in with the trike off the ground. My spouse speculates that perhaps this was occurring because the torque sensor on the original motor had failed, which seems likely.

I would still recommend anyone considering an assisted recumbent trike to purchase another brand than HPV, unless you have a dealer/distributor/mechanic that has the bandwidth and resources to deal with issues like this in a timely fashion. Recumbent PDX in Portand for instance is such a shop, so if you live in Portland I would recommend HPV, as they are great trikes. I happen to like working on my own bikes, but it's pretty aggravating having to put so much work into an OEM system. It's kind of the worst of all worlds - I still have to go through a shop and HPV to get parts and advice, but then I have to do all the work myself. With a fully DIY system, at least you can have the parts shipped directly to you, and there is a large community of people with knowledge of the system rather than a single company that is a black box and won't easily share information, separated from you by another degree via the manufacturer of the trike who act as a go-between.

That said, as far as OEM systems go, I can heartily recommend anything by Bosch. The Bosch CX system on our R&M, knock on wood, has been flawless, and is easily serviced at any number of local shops.

So, OEM: buy Bosch; DIY: do your research on local service options and community support.
 
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ckupcu

New Member
Hi Guys, I am new in this forum site. I came across your blog when I was desperate to repair my Go SwissDrive (G45p) hub motor. Because of the Covid-19, all brand bicycles shops are closed, Stoeckli is no exception - which they still service/repair these motors in Switzerland.

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Background:

I bought 6 weeks ago a broken 2016 model Stoeckli ET2 Men S-Pedelec, to repair as a hobiest and later use it. After fixing all mechanical issues, some paint job etc., I finally found myself to replace the motor due to two remaining issues:
1. Freewheel's outer aluminum part which is embedded to the rotor (teeth worn out)
2. Engine drive assist modes (1, 2, ... 5) were not functioning anymore (walking assist and recuperation modes were OK)

I finally decided to open and try to fix it myself when motor started short circuiting the 36V battery input and bicycle shops were still closed.

See the ET2 below after lots of cleaning, paint job on the mud protectors and all black parts, breake oil and pads change:
 

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ckupcu

New Member
2. Here is the electronics printed circuit board, which makes short of the 3-phases in the stator coil wiring. How do I detect there is a short (A) even when hub motor connector disconnected, when you spin the wheel you feel an increasing force with rotation speed (called back EMF in electronics. The more you spin the wheel, the stronger magnetic field you create; Stronge magnetic field induces current in the coil wiring, which in turn creates an opposite force to the wheels rotation). (B) when motors connector connected, battery block and the dispaly gives error, I immediately disconnected when this happened for the first time, but it was too late :-(((

You can see thick grouped wires at the south of the electronics board coming from coils. I suspect the high-power MOSFET devices on the backside of the PCB are dead (to be tested, I did not come that far):
 

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ckupcu

New Member
Here I post some other nice close up pictures from inside of the G45p hub motor. Which I could not do so far: Remove the coils from the motor housing. The reason for that, the rotor's strong permanent magnets pull the coils metal lamels so strong, there is no way I can pull it off without a special press (some one mentioned this previously in the blog, there is even an example video from YouTube with a similar hub-motor). I need to find a way to do that, otherwise I can not replace the worn out aluminum freehub housing which I mentioned earlier...
 

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ckupcu

New Member
Hope one of you guys have an advice / experience how to remove the coil assembly without damaging the magnets on the rotor side?

I decided to create a new thread to blog my repair experience, you can find it here.

Cengiz
 
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