Repairs to the TDCM hub motor

Stromer repariert keine Teile oder Komponenten von Stromern. Händler, die defekte Komponenten (Akku, Motor, Controller etc. ) einsenden, erhalten im Austausch Neuteile.

Bearing damage

Motor damage in newer Stromer models is rather rare. With the old 36 V motors (ST1 V1 / V1.1) with integrated electronics, there were still many problems and failures due to overheating and, in some cases, water ingress.

With increasing mileage, the engine mounts can become a problem, but are rather inconspicuous in the breakdown statistics.

A non-representative survey in the forum speedpedelecreview.com resulted in the following:

- Participants in the survey: 52
- Feedback on defective engine mounts: 18 (corresponds to 35% of participants)
- Average kilometers covered: 16,267
- 50% of the participants covered a distance of 10,000 - 20,000 km
- Average km until failure: 12,824 km
- Shortest distance to failure: 1,000 km
- Longest distance to failure: 27,000 km

The author summarizes that he had actually expected more participants in the survey. Since only 35% of the participants actually reported bearing damage and around 1,000-1,500 Stromers have been sold in the Netherlands every year since 2017, the negative response rate would have to be significantly higher if there was a real problem. Since there is also little to read about motor bearing problems on social media channels, he concludes that the problem cannot be major.

Bearing dimensions

The following bearings are usually used in TDCM motors:
Deep groove ball bearing: D=68mm, d=45, B=12, with ZZ (or 2Z) metal seal.

With Aliexpress there are corresponding replacements (in stainless steel) for approx. 20 CHF per pair. Brand bearings, e.g. from SKF, are better: 6909-2rs1 | 2 | 3

Es empfiehlt sich den Lagertyp anhand der vorhandenen Lager zu verifizieren, denn im Laufe der Modellentwicklung kamen Motoren von verschiedenen Herstellen (ASI, Ultra, TDCM), und dort wiederum verschiedene Typen, zum Einsatz.

Bearing repair by a specialist company

Riesewjik, Netherlands
Price tag: approx. 500 - 600 € (without shipping)

Bikes & Care, Netherlands
Price tag: unknown

Andrzej Romanow
E-Mail: attributebiker@onet.eu
WhatsApp: +48 50 809 87 18
Price tag: 160 € (without shipping)

All engine repairs

Bikes & Care, Netherlands
Price tag: unknown

Andrzej Romanow 

On the German portal classifieds.com there were advertisements from a supplier Andrzej under the geolocation 02828 Saxony - Görlitz, which advertised repairs of electric motors.

Display: (as of Jan. 2024)

Andrzej wrote to me on request:

My name is Andrzej and I live in Wroclaw, Poland. I've been involved with Stromer bikes for seven years and have a lot of experience with them, but mainly with the V1, ST1 and ST2 models...
In my workshop I have assembled the appropriate equipment and tools (see pictures below) to open, repair and refit Stromer rear wheels...
I have attached a price sketch (see above) to my classified ad offer. In addition, the details will be agreed in direct contact with the customer.

In den letzten zwei Jahren habe ich das Wiederverkleben von Magneten mit dem Stahlring in Stromer-Motoren perfektioniert. Zuerst habe ich Spezialwerkzeuge zum Aufkleben von Magneten auf das alte Modell ST1 gebaut und in den letzten Monaten habe ich zusätzlich ein eigenes Werkzeugset zum Aufkleben von Magneten auf den ST2 und neuere Modelle gebaut.

Contact:
E-mail: attributebiker@onet.eu
WhatsApp: +48 50 809 87 18
Price tag: See advertisement above

Feedbacks in the Stromerforum.ch

Repair: Hall and temperature sensor(s), stator magnets, motor cable, etc. Replacement of bearings.
Repair of defective spokes, rims. Re-spoking to alternative rims (DT Swiss 612/683 / RYDE Andra 29D)

Costs: Depending on expenditure: (as of July 2025)

• Bearing replacement from € 290. This service includes two splash-proof bearings, which are better than the dust-proof standard bearings. The engine is cleaned and checked internally.
• RYDE Andrea 29D rims (5 mm narrower) are very robust and reasonably priced.
  146 €, fully assembled.
• DT Swiss U 683 (if available), cargo rim.
  161 €, fully assembled.
• DT Swiss H 612, the standard rim for the Stromer ST5.
  179 €, fully assembled.

Contact:
Bart Berger, e-bike bike repair
Smidsestraat 93
9200 Grembergen (Belgium)
www: https://www.ebikewheelrepair.be/

DIY repairs

If you are a skilled craftsman, you can also get to work yourself. As always, there are different ways to Rome. A good thread can also be found in the speedpedelecreviewforum.com, and by user 'Lexveen', among others. He has dismantled a defective ST1x engine and describes the assembly with text and pictures.

Tool: e.g. PAULIMOT Universal puller, 3-armed, 300 mm span

There are also a few pictures of a disassembled TDCM engine here at pedelecforum.de

Hall sensors / temperature sensor

> See PROBLEMS > Motor - 'Hall or temperature sensor defective?

Repainting

> See PROBLEMS > Motor > 'Paint peeling off'