Stromer only uses brakes from the Taiwanese manufacturer for the newer models TRP (Tektro Racing Products). These are brakes specifically manufactured for Stromer and are not available for purchase on the open market. Older models also featured brakes from Shimano (Deore, SLX, XT) or Magura MT2/4/.5E) is installed.
Brake pads and brake disks of the same design can be purchased from dealers.
Brake pads


Brake calipers / brake lever / brake lever… TRP
A possible alternative for the Brake callipers HD942/944 4-piston are the TRP Orion 4P HD-M745 or the Slate T4 or 2-piston > TRP Slate X2 (OEM only).
Brake lines (e.g. ST1, ST1x, the Brake lever (e.g. HD942, ST3) or the whole Brake handles (HD942ST3) is available as a spare part.

Looking for the TRP gasket set or the Reed switch, it becomes difficult. When sealing the reservoir, it may be possible to use a liquid sealant, e.g. K2 Siltecor Round cord help.

I was unable to find a replacement or alternative for the reed switches that control the brake light and recuperation. They function electrically as normally open contacts.
Brake lever... Magura
Stromer also used brake levers from Magura, for example on the ST2S or the older ST2 with the MT5e. The ST2 6V used MT4. The levers are also available individually from Magura. If you replace a lever completely, you may need to resolder the connector from the old lever (3-pin) to the new one, as it only has 2 pins. In terms of wiring, this is sufficient, as only one normally closed contact needs to be switched through.
Brake disks
The ST3/ST5 originally has the 4-hole TRP 203-31 at the rear and the 6-hole at the front (after IS 2000) TR203-29 (Ø 203 mm / t=1.8 mm) are installed. Alternatively, there is the floating front TRP TR-33 - 6-hole. There are also alternatives at the rear: Hope | Rohloff | Rohloff 2

Hydraulic oil
The TRP and Magura brakes use non-corrosive mineral oil with an increased boiling point of 270 °C and low viscosity for good flow behavior. Sources of supply: EN | CH | Universal venting set
Brake hose / olives / clamping screw / pad retaining screw
If the brake hose needs to be replaced, this is usually a job for the workshop. If you want to do it yourself, you need to know which hose, which pinch seal (olive) and insert pin as well as screw connection must be used.
Here the specifications for the Tektro TRP xx brake that is usually fitted.

Conversion
Alternatively, a conversion to a different braking system, such as the Magura MT5e used on the ST2S, is also possible. The conversion is described by user RoadCruiser in the stromerforum.ch. here. Always note the Provisions of myStromer AG.
Original spare parts
See FAQ - 'Spare parts - where can I get the originals?
See TRP brake small parts