MOTORS

SL Motors: Common Design Features

SL Motors: Hardware Features

Working principle

• Brushless 48V motor, geared

Weight

• Around 1.95 kg

Housing

• Magnesium housing for lower weight; corrosion-resistant surface treatment

Motor covers

• Attaches to the underside of motor
• Secured differently, depending on bike family

Mounting

• Direct to frame with 6 bolts, 3 each frame side
  • Mounting varies slightly between the Turbo SL bike families
  • For bolt dimensions, see schematic on Service Website/B2B, filed under each Turbo bike

Connectors

• 2 connectors
  • (1) Power supply from main harness/battery
  • (2) Speed sensor cable

Integrated Sensors

• These sensors send their data to the bike display and can be read via external ANT+ devices
  • Rider power (highly accurate dual sided torque sensor)
  • Speed
  • Cadence

Freewheel & Internal Design

• Instant engagement freewheel technology
  • No lag when beginning to pedal
  • No drag when there is no motor support
• Critical circuit board is not located next to actual motor to avoid thermal issues; generally, motor cannot overheat thanks to clever design features

Bearings

• Double sealed bearings + additional radial seal for best and lasting sealing results
• Despite great sealing, we only have about 1.5 watts loss through motor seals, which means a SL rides like a normal bike when powered off (normal bottom brackets also have around 1 watt)

Protection Rating

• High IP67 ingress protection rating through double sealed bearings + additional radial seal on both sides of unit (yet, pressure washing not recommended)

Thermal Management

Under normal riding conditions, most riders will never experience power reduction due to overheating. In extreme conditions, the motor is designed to reduce power slowly, but it will most likely not get into a temperature range where it shuts-off completely. Bear this in mind:

• The system is very efficient and offers best-in-class heat management
• Under extreme motor temperatures, the system first slightly reduces motor power, which will be hardly noticeable; it would reduce power more noticeably when temperature rises further
• Heat build-up primarily depends on
  • Terrain conditions (gradient, surface)
  • Motor support level (higher Support/Peak Power = more heat)
  • System weight
  • Ride time with high loads
  • Ride style (low cadences create more heat)
  • Ambient temperature
• The rider cannot damage anything because the system is self-protecting, but can act in a way to avoid unnecessary heat build-up by:
  • Pedaling in a higher cadence spectrum (75rpm +)
  • Not leaving the bike in the sun when not riding
  • Avoiding unnecessary weight/resistance

Light Connection

• SL motors do not feature light ports at the motor
• Lights connect to the `Y-SPLITTER FOR LIGHT` at display (S216800001)
• 12 V only, 8 W/650 mA max.
• For details, refer to the Turbo Studio Knowledge Base article `Guideline to connecting wired lights´

Warranty

• 2 years (from purchase date)
• Important: Please contact your Rider Care / Service team for Assisted Purchase offers for all issues related outside warranty

Type Overview

Performance Curves

Testing and graph designation

• Multiple samples of SL motors were tested in the independent Velotech test lab and on in the in-house motor dyno
• The y-axis (vertical) represents motor performance
• The x-axis (horizontal) represents the rider cadence (crank rotations per minute/rpm)

Motor Calibration

General

Both SL 1.1 and SL 1.2 motors feature a torque sensor that is calibrated during the production process. The torque sensor measures rider torque to ensure:

1. Accurate calculation of rider power
2. Smooth delivery of motor power

Should the torque sensor be out of calibration (torque sensor drift/offset), a rider would see unstable or unrealistic power values and/or experience intermittent or unnatural motor power delivery.

Examples/guidelines:

• The greater the offset, the greater the power reading inaccuracy
• An offset greater than +/- 5 Nm is increasingly noticeable when riding
• If the motor has a negative offset of 10 Nm, the rider will need to provide 10 Nm more input to deliver expected motor support

Calibration

SL 1.1 and SL 1.2 motor have partly different behaviour and requirements with regard to calibration and use of our digital tools.

Criterion	Torque sensor in SL 1.1 Motor	Torque sensor in SL 1.2 Motor
General	Manual calibration If a torque drift got detected, the motor needs to be calibrated through Turbo Studio.	Self-calibration The SL 1.2 motor uses a learning algorithm and adapts to the rider, which means it is able to self-calibrate while riding.
Firmware	No option to see and/or update firmware in Turbo Studio	Torque sensor firmware is visible in Turbo Studio and Bike Inspector. Firmware can be updated together with motor firmware, but will rarely happen.
Turbo Studio (calibration)	Generally required for calibration Prompts calibration once bike got connected	Only required in case of a high torque sensor drift Manual calibration only prompted if a higher torque sensor drift (e.g. > 5 Nm) was detected and self-calibration was not successful. If a user clicks on «Motor Calibration» dialogue box with an info message opens. Message must be confirmed with «Proceed» to be able to enter the motor calibration feature.
Turbo Studio (Event Log)	Both motors log the detection of torque offset in the Event Log. These events can be seen in Turbo Studio after connecting the bike or after uploading the event log through Mission Control.
Mission Control	Torque offset events are not displayed to riders in Mission Control.

Turbo Studio captures these different offsets in the Event Log: Recommendations are based on ride feel (a significant positive offset creates a jerky ride feel, whereas a negative offset does not compromise the ride feel).

Event Log	Offset	Manual calibration recommended/flagged in TS
TQSDrift_plus2_5Nm	2.5 to 5 Nm	No
TQSDrift_plus5Nm	5 to 7.5 Nm	Yes
TQSDrift_plus7_5Nm	7.5 to 10 Nm	Yes
TQSDrift_plus10Nm	More than 10 Nm	Yes
TQSDrift_minus2_5Nm	-2.5 to -5 Nm	No
TQSDrift_minus5Nm	-5 to -7.5 Nm	No
TQSDrift_minus7_5Nm	-7.5 to -10 Nm	No
TQSDrift_minus10Nm	More than -10 Nm	Yes