- 100 day return period
- Online since 1998
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The DFour DUB power meter spider by QUARQ - concentrated power meter know-how
With the QUARQ DFour DUB power meter spider you can equip DUB cranks with an 8-bolt interface, e.g. the DUB Carbon cranks, with power measurement functions. The spider was designed for Shimano Dura Ace R9100 chainrings, but is also compatible with Ultegra R8000 or 105 R7000 chainrings. The power meter platform contains more than a decade of experience with power measurement technology. DFour impresses with excellent temperature compensation, 200 hours battery life, ANT+ and Bluetooth data transfer and last but not least with MagicZero™, an automatic calibration while riding. Add the smart DUB bottom bracket technology and you get a product that is second to none in stiffness, reliability and weight optimisation.
Information regarding the return of batteries and electrical equipment:Information on the return and disposal of used batteries and electrical equipment can be found here.
- Road, Triathlon & Time Trial
- spider with power measurement
- Chainring Mount:
- 110 mm bolt circle, 4-arm asymmetrical
- DZero (DFour)
- Axle Diameter:
- 28.99 mm
- Recommended Bottom Bracket:
- all SRAM Road DUB
- +/- 1.5%
- Point of Measurement:
- Power Source:
- CR2032 lithium battery
- Battery Life:
- approx. 200 hours
- Data Collected:
- power (dual-sided), cadence, torque, pedal stroke uniformity
- Data Transfer:
- ANT+, Bluetooth
- cranks with an 8-bolt interface and DUB axles
- Shimano Dura Ace R9100 chainrings
- Shimano Ultegra R8000 and 105 R7000 chainrings (visually not the best fit)
- SRAM AXS app for zeroing, battery status, diagnostics and firmware updates
- 8-bolt interface
- DUB: stronger, stiffer, lighter
- tool-free battery replacement
- 10K temperature compensation (programmed with over 10,000 data points)
- no cadence magnet required thanks to AxCad (multi-axis acceleration sensor)
- automatic recalibration while riding
- LED status display
- standby after 10 minutes of inactivity, automatic restart by crank rotation
- easy chainring change without recalibration
Technology:QUARQ Operating Principle
The crankset forms the heart of your bike. Their only task is to convert the force of both legs into forward motion - the perfect place to measure performance.
Power meters calculate power by measuring torque (pedal force) and angular velocity (cadence). Power = torque x cadence. When you pedal, all parts of the bicycle drivetrain shift (bend) slightly under the load. Power meters are designed using FE analysis so that these displacements take place in a very controlled manner and at specific locations in relation to the applied load. Strain gauges are used to measure this displacement and calculate the applied torque. Reed switches are used to calculate the cadence.
DZero is QUARQ's next generation power meter, named after the DZero Experiment, one of the most accurate and innovative scientific projects to discover subatomic particles. With a revised measurement loop, optimised strain gauge design, increased accuracy and the features of the Qualvin and SRAM AXS App, DZero represents the state of the art in power meter technology. You can choose between Bluetooth LE and ANT+ technology for data transfer. A simplified product line makes it easier for you to find the right power meter for your bike.
The power measurement depends on the choice of the right chainring. Change from a Road to a Time Trial chainring without sacrificing accuracy. No recalibration necessary.
Calibration takes place automatically during the ride. You don't need to pedal backwards or perform a manual calibration from your computer.
- 1 x QUARQ DFour DUB power meter spider
- 1 x CR2032 batteries
- black/110 mm: 165 g