FarDriver Ratio In Speed and Gear Ratios for ONYX RCR

This article explains how riding-mode ratios and RPM-dependent current scaling interact on the ONYX RCR FarDriver builds described in the reference.

Reference Applicability

The explanations and tables below are the blog’s recorded FarDriver parameter reference, not a universal tune. The complete settings snapshot remains in Jaws Mode Settings. The parameter reference and settings snapshot have unresolved differences: 500 RPM is 100% versus 98%, 2250 RPM is 80% versus 58%, and LowSpeedPhaseRatio is 65% versus 60%. Their revision/hardware basis is not recorded. Do not combine the records or overwrite motor-specific learned values.

Firmware labels, scaling, motor pole pairs, installed wiring, and battery limits determine applicability. Interpret descriptions of riding feel as the source’s explanation, not proof of an outcome on every build.

Current Limits and RPM Interpretation

MaxPhaseCurr is the phase-current limit associated with motor torque; MaxLineCurr limits battery-side current and available electrical input power. A ratio does not establish a safe current ceiling for the battery, controller, motor, or wiring.

FarDriver’s control-parameter instructions distinguish phase current from battery current and explain pole-pair conversion for the RPM current-limit table. Confirm whether an app/table shows motor mechanical RPM or a scaled reference before applying a curve. The source tables below retain their recorded RPM labels. The displayed RPM rows must not be assumed to equal wheel RPM on every firmware.

The manufacturer describes current-limit shaping in the field-weakening region. That supports considering the curve and weakening together; it does not establish that every firmware implements every interaction described below identically. Verify the controller version and stop testing if no-load behavior becomes unstable.

THREE SPEED PARAMETERS

Core behavior:

• These parameters scale both torque and speed depending on selected gear mode
• Power outputs control phase current (torque), while speed settings control maximum RPM
• They act as multipliers on the main system limits rather than independent values

Interaction layer:

• Gear Power Output directly scales MaxPhaseCurr, affecting torque across the RPM range
• Gear Speed scales LimitSpeed, controlling maximum achievable RPM
• Combined effect determines final torque curve when paired with RatioInSpeed

Real-world behavior:

• Low gear -> reduced torque and speed, improved control and lower heat
• Mid gear -> balanced performance and efficiency
• High gear -> full system output with maximum thermal load
• Gear switching allows dynamic control of performance without changing core parameters

Limits and failure modes:

• High gear sustained -> increased heat and potential overheating
• Low gear too restrictive -> poor acceleration and limited usability
• Mismatch between power and speed scaling -> inefficient performance (high torque with low speed cap or vice versa)

Tuning Guidance (ONYX-Specific)

• Use low gear for traction, thermal control, and urban riding
• Use mid gear for balanced daily riding with controlled heat
• Reserve high gear for full-performance use and short bursts
• Do not rely on gear scaling to compensate for incorrect MaxPhaseCurr or MaxLineCurr settings
• On QS motors, excessive high-gear usage under heavy load will rapidly increase heat - monitor temperatures closely

CONFIGURATION VALUES

Core behavior:

• These values define how much of the system’s total torque and speed are available in each gear
• Power and speed scaling work together to shape overall performance per gear

Interaction layer:

• Power outputs scale MaxPhaseCurr, directly affecting torque across all RPM ranges
• Speed values scale LimitSpeed, defining the maximum RPM per gear
• Combined with RatioInSpeed, these values determine the full torque curve in each gear

Real-world behavior:

• High gear (100/100) -> full performance, maximum acceleration and speed
• Mid gear (85/85) -> balanced performance with reduced thermal load
• Low gear (55/55) -> controlled output, improved traction and lower heat

Limits and failure modes:

• Sustained high gear usage -> increased motor and controller heat
• Low gear too restrictive -> poor usability at higher speeds
• Imbalanced settings (high power, low speed) -> inefficient performance

Tuning Guidance (ONYX-Specific)

• Keep high gear at 100% for full system capability when needed
• Use mid gear (~85%) as the primary riding mode for balance between performance and heat
• Use low gear (~55%) for traction control, wet conditions, or thermal management
• Avoid running high gear continuously on QS motors under heavy load - monitor temperatures
• Adjust gear scaling only after core parameters (MaxPhaseCurr / MaxLineCurr) are correctly set

FINAL TORQUE RELATIONSHIP

Core equation:

Final Torque = MaxPhaseCurr × Gear × RatioInSpeed

Core behavior:

• Final torque is not fixed - it is dynamically scaled by gear selection and RPM-dependent reduction
• MaxPhaseCurr defines peak torque, but actual output is continuously modified by Gear and RatioInSpeed
• As RPM increases, RatioInSpeed reduces effective current to control heat and maintain stability

Interaction layer:

• MaxPhaseCurr sets the upper torque limit
• Gear acts as a multiplier that scales available torque for different riding modes
• RatioInSpeed reduces torque as RPM increases, preventing excessive heat and inefficiency
• All three must be balanced to maintain usable acceleration across the full speed range

Real-world behavior:

• Low RPM + high gear + high phase current -> maximum launch torque
• Mid RPM -> torque begins tapering for efficiency and thermal control
• High RPM -> reduced torque, smoother pull, lower heat generation
• Aggressive settings -> strong initial acceleration but rapid thermal buildup

Limits and failure modes:

• High MaxPhaseCurr without tapering -> excessive heat and motor stress
• Flat RatioInSpeed (no reduction) -> overheating at sustained speed
• High gear with high current -> strong performance but reduced efficiency
• Poor balance -> either weak acceleration or unstable thermal behavior

Tuning Guidance (ONYX-Specific)

• Set MaxPhaseCurr first based on motor and controller capability (QS motors heat quickly at high current)
• Use Gear scaling to control usable torque without changing base current limits
• Ensure RatioInSpeed tapers torque above mid-RPM to prevent overheating
• Do not run high phase current with a flat ratio curve - this will overheat the motor rapidly
• For ONYX builds, prioritize a tapered torque curve for sustained performance rather than peak output

RATIO IN SPEED

LD: 900
LQ: 339
FAIF: 128
LimitSpeed: 2800

Core behavior:

• The system operates in two distinct regimes:

  1. Torque-Dominant Region (≈ 0-750 RPM)

     • Acceleration is driven by MaxPhaseCurr
     • Torque is the primary source of performance
     • Heat rises rapidly due to high current

  2. Weakening-Dominant Region (≈ 1000+ RPM)

     • Speed is maintained by field weakening (voltage-driven)
     • Torque becomes secondary and continues to drop
     • Efficiency decreases while instability risk increases

• The region between ~750-1250 RPM is a transition zone where:

  • Torque begins tapering
  • Field weakening starts contributing
  • Control shifts from current-driven -> voltage-driven

Core equation:

Effective Phase Current = MaxPhaseCurr × Ratio

Interaction layer:

• Ratio In Speed reduces available torque as RPM increases
• Field Weakening compensates for torque loss to maintain speed
• MaxPhaseCurr defines the ceiling of torque in the low-speed region
• WeakCurrCoeff and WeakResponse define behavior in the high-speed region

Real-world behavior:

• Low RPM -> aggressive, torque-heavy acceleration
• Mid RPM -> smoother pull as torque tapers and weakening begins
• High RPM -> speed continues increasing, but pull feels weaker
• Riders perceive this as “strong launch, softer top-end”

Limits and failure modes:

• No taper -> excessive heat and motor saturation
• Too much taper -> weak mid-range performance
• High weakening + high current -> instability at speed
• Ignoring transition zone -> poor tuning balance between launch and top speed

Tuning Guidance (ONYX-Specific)

• Treat <750 RPM as your torque tuning zone
• Treat >1250 RPM as your weakening / speed tuning zone
• Use the transition zone (~750-1250 RPM) to smooth the shift between the two
• Do not try to maintain torque at high RPM - this only creates heat
• Balance Ratio In Speed with Weakening settings for stable high-speed performance

RATIO IN GEARS

Core behavior:

• Ratio In Gears defines gear-based scaling of torque and power, independent of RPM-based scaling
• It acts as a global multiplier layer on top of MaxPhaseCurr (torque) and MaxLineCurr (power)
• Unlike Ratio In Speed (dynamic), this system is static per gear selection

Core equations:

Effective Phase Current = MaxPhaseCurr × GearPhaseRatio
Effective Line Current = MaxLineCurr × GearLineRatio

Interaction layer:

• Works in parallel with Ratio In Speed:
  • Gear ratios = coarse adjustment (per gear)
  • Speed ratios = fine adjustment (per RPM)
• Directly scales:
  • MaxPhaseCurr -> torque output
  • MaxLineCurr -> total power
• Interacts with:
  • Throttle system (changes perceived response)
  • Thermal system (lower ratios reduce heat globally)

Real-world behavior:

• Low gear:

  • Reduced torque + reduced power
  • Smoother throttle, better traction
  • Lower heat -> safer for sustained riding

• Mid gear:

  • Full torque and power restored
  • Balanced performance

• High gear (implicit 100%/100%):

  • Maximum system output
  • Highest stress and heat

• Riders experience this as:

  • Low gear -> controllable / tame
  • Mid gear -> normal
  • High gear -> aggressive

Limits and failure modes:

• Too low phase ratio -> bike feels weak and unresponsive
• Too high ratios in all gears -> no thermal control, increased overheating
• Incorrect RPM thresholds -> awkward gear transitions or overlap
• Using gears to compensate for bad tuning -> masks underlying issues

Tuning Guidance (ONYX-Specific)

• Use Low gear (≈50-65%) for traction and thermal control on QS motors
• Keep Mid gear at or near 100% for balanced riding
• Use High gear as full-output mode only when needed
• Set RPM thresholds to match real riding conditions:
  • LowSpeed -> end of usable traction zone
  • MiddleSpeed -> transition into high-speed operation
• Do not rely on gear scaling to fix overheating - correct current limits first

Related Articles

• Settings reference: Jaws Mode Settings
• Next step after configuration: Calibration and Validation