Go SwissDrive rear hub drive motor repair


New Member
Hi Guys, I am new in this forum site. I came across EBR when I was desperate to repair my Go SwissDrive (G45p) hub motor. Because of Covid-19 lock-down, all brand bicycle shops are closed, Stoeckli (https://www.stoeckli.ch/) is no exception - which they still service/repair GSD motors in Switzerland.

(This is the original thread where I post my comments first, but I decided later to start a new thread as my problems are different)

This is a good start before reading my text:



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.

I decided to undo only one half of the spokes (18x), those on the free hub side. Two reasons for that:
(A) to keep the most tensined side untouched, so that when I redo the tire, truing effort will be minimal
(B) it is sufficent to open the GSD hub motor from one side only


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New Member
1. Here is the mechanical issue in the hub motor: I removed the SRAM XD driver body and found out that teeth worn out. XD driver body look still OK, I wish this had the issue :-(

ps: I could not removed the "Free-wheel stator" part yet...


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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 display 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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New Member
2. cont'd...

I measured the N-MOSFET power transistors (IRFB3607 P512D in TO220 heatsink packaging- there are 12x, 4x per phase), 2x of them which belongs to 2nd phase was broken.
(Here is the data sheet: https://www.infineon.com/cms/en/product/power/mosfet/12v-300v-n-channel-power-mosfet/irfb3607/)

If you connect a multi-meter in "Diode" measurement mode, you can see if the transistors still good or they were dead. In my case, 2x of them were showing "short" i.o. showing 0.5V forward-bias on voltage drop.

Assuming the remaining 10x working power transistors may also be worn out, coming to their end of service life, I decided to replace all 12x at the same time. Each costing about 2.5 CHF in (www.digikey.ch). Note that, opening/closing such a hub-motor is pain in the neck, it is better do a "preventive" maintanence/replacement before the other also die later ;-)


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Well-Known Member
. In my case, 2x of them were showing "short" i.o. showing 0.5V forward-bias on voltage drop.

Assuming the remaining 10x working power transistors may also be worn out, coming to their end of service life, I decided to replace all 12x at the same time. Each costing about 2.5 CHF in (www.digikey.ch).
The problem with those MOSFET's is that there is no heat sink attached to the tab. Reason for a $25 remote controller instead of the dingbat controller inside the hub motor. May be reason goswiss went bankrupt. BTW the beautiful aluminum heatsink around all $25 controllers is not attached to the mosfets. BUT, you can take the case off & modify to make the heat actually flow to that beautiful case for $12 in insulator pads and some scrap aluminum


New Member
Hi @indianajo,

I am happy that at least one person read my text :)

My GSD seems to have a heat sink, may be they did some update, see pictures below. Blue tapes are actually .25mm thick silicon based insulator/heat coupler. They are attached and pressed to the aliminum part of the stator behind. See the second picture, they are screwed down with 3 clamps on the other side of the PCB. You can see on the 3rd picture the CNC machined flat surfaces on the aluminum base where those 3 silicon couplers sit. And on the 4th picture, you can see the close-up imprint of the TO220 driver transistor couplers on the surface of the aluminum...

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New Member
2. cont'd...

I have also changed 3x IC (Integrated Circuits) so called the Gate Drivers (HMAL L5101AM National Semiconductors, which I also sourced from www.digikey.ch, price was in a dolar range per piece). I did this as a "preventive" maintanence together with those 12x IRFB3607 MOSFETs, in case those 2x broken ones might have leaked some current and destroyed the Gate Driver(s) behind.

Note that, those 3x Gate Drivers are actually the last barriers before the CPU which controls everything. If excessive current flow over to CPU, you can not repair the PCB yourself anymore. This is because you need to have access to the right FW code, encryption, etc --> forces you to bring it to the official GSD service to replace the whole PCB :-(


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New Member
2. cont'd...

I closed the GSD temporarily for testing the electronics after I finished replacing 12x IRFB3607 and 3x L5101AM electronics components. I was positively surprised when I did not receive below errors (C64: check cabling, D300: display error, M4165: unknown error code) any more:

I cleared these errors from the menu above with "Delete list" option, then ran my tests (walking assist, recuperation and 5 drive assist modes). I span the wheel up and slightly beyond 45km/h limit, I could feel and hear electric motor was engaging in parallel to my own force (torque), all looked fine - no errors received :)

My guess for all those three groups of errors were due to the leakage current which flow over other electronic components on the PCB and creating unexpected random signals/communication problems with the display.

At this stage, I assume I fixed problem # 2. (electronics) for the time being - assume, because I could not have tried the motor under load as wheel was not fully mounted (remember, 18 loose spokes on the other side mounted only)
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New Member
1. cont'd...

Back to # 1. (mechanical) problem, replacing the aluminum Free Wheel Stator (above)

Last Moday, 11 May; Swiss constitution decided to relax Covid-19 lock-down and open primary schools as well as most of the companies in Switzerland. As a result, I could get someone on the phone from company Ortlinghaus (https://www.ortlinghaus.com/)

Ortlinghaus is the German company which acquired the GSD motor and display from Swiss Stöckli (https://www.stoeckli.ch/) 2 years ago, but they still have a site in village Gams in Switzerland.

I called the front desk on Monday, 11. May, the old receptionist lady asked me to call in on Wednesday to speak with a GSD service representative... After waiting 8 weeks due to covid lock-down, I was quite impatient, asked the old lady to give me at least some responsible person's e-mail to connect electronically...

... I got it. Wrote the e-mail, explained the whole story and wanted to get some quotation for the abused free wheel stator... and the answer I got:

" 1. We do not sell spare parts, but we have all what you need to repair. You must send the motor to us for service
2. We do not give service to individuals like you, please send the motor via official bicycle shop

our advice: it is best if you replace the whole GSD..."

I guess, you can now imagine why GSD was not successful and sold to Ortlinghaus, and the hysteria still continues under the new company... what a waste...

They gave me no choice. I contacted with a friend from my company, he is running a special bicycle on-line shop (www.light-bikes.ch) as part time to help me bridge it with Ortlinghaus service in Gams. After all e-mails, etc. finally I got confirmation to bring in the GSD motor to them, but all e-mail and billing to be done via my friends company - OK, that's something!

I left the GSD motor and LCD display to them last week on Wednesday, 20 May. Here is what they will do:
- They proposed to change the whole right-half GSD aluminum housing together with the Free Wheel Stator
- Check the ball-bearings on both sides, if necessary replace them
- Run an electronics diagnostics, if FW upgrade needed do it, re-calibrate the motor ( I guess Hall sensors may need some SW trimming , that's all)
- If LCD display needs FW upgrade, do this
- Run full-check (GSD + LSD)

Current offer: 213 CHF + VAT (which is similar in USD) - You guys might think this is rip-off, indeed it is like this in Switzerland. But still better off buying a refurbished GSD motor from Germany for 550 EURO or a complete new one for 1300 EURO or one for more than 2000 CHF from Switzerland...

Now waiting...
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Well-Known Member
I'm willing to pay a premium to support some free workers instead of the serfs & prisoners of ****, but you've put up with entirely enough pride & lack of service. Pitch it & buy something else.
I was willing to spend $2000 for a swiss Meagher hub motor in 2018, instead of supporting the land of a million prisoners in jail because they look wrong. I'd spotted meagher in 2017 at a san diego shop, but didn't have the money. When I had the money, none of the 3 "US distributors" listed in the meagher website would answer my emails. Screw them, I bought a $221 hub motor built in the prison and am still using it 4000 miles & 2 years later. 1500% premium is not worth the bother. I could make one for E1300, coil winders are not that expensive. At least every mile I use electricity generated from coal screws the exporters of oil who cause so much death with their profits..
You ought to be able to lace a new motor in your old wheel. Warning spoke calculators lie a lot, be prepared to buy 3 lengths of spoke to get the right one. The throwaway spokes could be ****ese, but the final ones I'd ante up for DT swiss. Buy a motor with an external controller this time.
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New Member
I knew I would have several difficulties like this when I bought this broken eBike. I got it for 388.- CHF in an auction, original price was close to 6K 4 years ago. I spent so far about 400 CHF for new parts and paint work. If I spent another 250 for the GSD motor, I am done around 1K - which is fantastic value for this eBike!

But put all these aside, repairing this during Covid-19 lock-down is an awesome therapie :)

I can easily assemble another hub motor into this bike, this is no problem. But I am trying to fix as original as I can - and GSD hub motor is one of the esential Ingrediens...

Thanks for the advice on spoke lenght, very valuable tip. I am checking now alternative hub motors (Grin Technologies is an invaluable source of information).


New Member
Hi i have recently attemted, also to fix my goswiss drive (specialized turbo s 500w motor). My problem was bad bearings on the free wheel stator side. So i dissasambled whole wheel and motor, opened both sides of motor. Pressed and replaced the bearings. I put the wheel together, attached spokes. I connected wheel and something is not right. When i select no assist program wheel spins freely, but on asisst mode ex. Turbo motor stops and generate force when you spin the wheel. Can anybody tell me What could be the problem? Also i was wondering how to take off the free wheel stator part and replace it with new one, but for now i decided Only to change bearings. I will appreciate every information given :) thanks


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New Member
Hi i have recently ... Can anybody tell me What could be the problem? Also i was wondering how to take off the free wheel stator part and replace it with new one, but for now i decided Only to change bearings. I will appreciate every information given :) thanks

Hi Skotie,

1. You wrote with assist mode on, when you spin the wheel you feel force. Did you get any warning or error on the display? My one was giving some unknow engine warning/error messages. As I wrote above, 2 of the output driver MOSFETs were burned. After I replaced them, wheel was spining nice, without back force... But, your electronic problem seems to be slightly different than my one...

2. I got my GSD (G45p) back from Ortlinghaus 2 weeks ago, I will continue my blog later after the saga completed! They changed the complete left and right housing (which contains ball bearings, magnetic speed sensor, free wheel stator part as well as XD driver body. The lady at the service said, removing free wheel stator alone from the right housing is not a recommended repair work. They also refused to sell me free wheel stator as spare part :-( But, they did a good job and gave me 1 year warranty with the condition that I do not open the motor during this time ;-) They did not tell me weather they replaced/repaired the PCB, I suspect not, but I have no solid evidence as I do not dare to open it again (warranty)
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New Member
1. cont'd...

I got my GSD (G45p) back from Ortlinghaus 2 weeks ago, they charged me 239.- CHF (i.o. 213.-) They changed the complete left and right housing which contains ball bearings, magnetic speed sensor, free wheel stator part as well as XD driver body. They did not tell me if they changed or repaired the PCB or coil array. At least cable was sill my original one. As they gave me 1 year warranty, I decided not to open it again:



New Member
I have rebuilt the rear wheel last week :) I used X-Tools Wheel truing stand and X-Tools spoke tension meter, they are reasonably chep and good guality. Truing process took me about 2h. I used the original spokes, but I completely replaced all nipples with 12mm DT-Swiss black nippels.


New Member
There it is :cool:

20200524_023846.jpg 20200524_023829.jpg 20200524_023753.jpg

First test result:
- No FW change, still my last version
- No more warnings or errors :)
- My old data still there
- Recuperation works

20200526_005642.jpg 20200526_010604.jpg 20200526_010557.jpg 20200526_005649.jpg

Second test, 1h ride in the city (mostly flat, using riding assist 1, 2 and 3):
- Managed to increase the range up to 200km !!!


So far so good... Next step is to register it to Street Office and get a new yellow Mofa number plate...


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New Member
I was once replacing the bearings on Specialized GSD. It is important to remount the housing parts exactly as they have been. You could try out all possible positions on a stand to get back to the original state.


New Member
Many thanks for your posts, very interesting. I have done some mechanical repairs on the GSD, up to now with success. Generally the freewheel needs cleaning and relubrication. Since 2013 I did not manage to wear the teeth in the motor housing.
Did you check the processor on the controllerboard? Is it a MSP430? I would like to download the firmware of different GSD OEM’s to be able to flush new motors.
My original GSD in the Specialized Turbo is working but there are some communication errors. I would like to get rid of them.

Scott Adams

Active Member
There it is :cool:

So far so good... Next step is to register it to Street Office and get a new yellow Mofa number plate...

Congratulations on a great job!

Is this still the same motor that has the FETs you removed and replaced on your own? It would be fun to know that part of the repair went well.

I've only tried truing a wheel once, I didn't have a tension meter or a truing stand and it was too difficult, so I always bring wheels to the shop for truing. All that to say how impressed I am that you bought the stand and meter and did that yourself as well!

EBR is almost exclusively composed of riders who buy ready made bikes and don't repair anything themselves, so these kinds of threads don't get as much attention as they deserve.

Thanks for taking the time to post your story and photos.

Happy riding.