Swift has successfully developed the first true force vector measuring bike cranks available.

 

Until recently we have only supplied systems suitable for stationary ergometers, but recent developments have allowed a complete re-engineering of our patented technology into a crank suitable for most bikes with a 68mm bottom bracket.
Each crank is identically instrumented to deliver tangential and radial forces, as applied at the pedal plus effective crank angle (horizon referenced).

These forces, combined with crank angle allow us to deliver force vector.

The AXIS system consists of two measuring cranks fitted with strain gages and mounted on both sides of the bicycle. Measurement of the force vector individually in each crank arm allows the measurement of the ratio of GROSS input power and NET output power.

AXIS Cranks measure the main set of orthogonal crank forces in polar coordinates, crank torque (Ftangential x Length) and the crank axial force, Fradial. Since the crank angle is also recorded simultaneously the force basis in polar coordinates is easily transformed to a rectangular basis to derive the vertical and horizontal components of pedal forces Fz and Fx.

HZ Sample rate

+/- Newtons Range

Deg. Angular Resolution

Design

The crank has been designed to fit most bike frames. It utilizes a compact chain-wheel spider fitment and has been dimensions to provide frame clearance similar to Shimano Ultegra cranksets

Geometry

The crank has been designed to fit most bike frames. It utilizes a compact chain-wheel spider fitment and has been dimensioned to provide frame clearance similar to Shimano Ultegra cranksets

Bottom Bracket

The bottom bracket design is unique to AXIS and provides a 30mm BB tube attached to the cranks via a parallel splined interface with internal taper bolts for an expansion fitting. This approach allows fitment to varying bb tube lengths up to EVO 386 styles. Fitment to standard 68mm BB tubes is simply accomplished using outboard 30mm bearing carriers.
Further safety crank retaining bolts ensure the integrity of the system as a secondary safety
The Bottom bracket is available in both Aluminium and Stainless steel….along with the expected weight penalty 

Length adjustment

The crankset is supplied with a range of tapered pedal mount blocks giving adjustable length options in 2.5mm increments between 177.5mm and 167.5mm 

Data

Data is delivered wirelessly by way of Analog Interface Receiver (AIR). There are two methods of collecting data.

 Analog data is delivered via BNC connectors on the AIR box. There are outputs for Left Radial (N), Left Tangential (Nm), Right Radial (N), Right Tangential (Nm), Angle, and a Sync output that can be set to pulse at any preset angular position

 Digital data is delivered to our AXIS application via Bluetooth. Only the supplied Bluetooth dongle should be used.

 

Cranks

  • Microprocessor – 32 bit M0 Processor
  • Battery- 400mAh Lipo- rechargeable
  • ADC 12 bit absolute , 16 bit oversampled
  • Radio- Propriety ISM band 2.4GHZ
  • Force measurement via patented strain gauge placement
  • Angle- MEMS Acc/Gyro combo
  • Materials- 7075 CNC machined

A.I.R. Receiver

Our Analog Interface Receiver has the following Charteristics

  • Microprocessor – 32 bit M0 Processor
  • Power 7V DC 200mA plug pack
  • ADC 12 bit absolute , 16 bit oversampled
  • Radio- Propriety ISM band 2.4GHZ for Receive from Cranks.
  • Bluetooth 2.1 for connection to PC
  • Outputs via BNC connectors
    • Analog Left Radial 16 bit +/-2000N (0.5 to 4.5V)
    • Analog Right Radial 16 bit +/-2000N (0.5 to 4.5V)
    • Analog Left Tangential 16 bit +/-2000N (0.5 to 4.5V)
    • Analog Right Tangential 16 bit +/-2000N (0.5 to 4.5V)
    • Angle SYNC pulse 0-5V TTL
    • Angle Analog stepped 0-1V DC 0-360 degrees

General

Axis cranks are designed to communicate with a remote receiver. Data is available via Bluetooth (up to 200 hz max, or via the analog BNC outputs at rates up to 400hz.

Transmission Range

  • Crank to AIR
    • AXIS cranks are designed to transmit a maximum of 6m, line of sight to our A.I.R. Receiver
  • Air to PC (Bluetooth)
    • Normal blue tooth range is to be expected. Allow 25m maximum for best results

Start-Up and data collection

  • Cranks start after 3 complete revolutions and remain on for 5 minutes after last detected loads
  • Data is available immediately after start up.

Software

  • AXIS Software offers the following features
    • Visualize all force components
    • Visualise angle
    • log data

Our Research Partners

Used by the worlds best, Swift is the only option if you are serious about athlete testing and training

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