Description

Promax HF‑2 BMX Crankset with SRM Spider PowerMeter – Maximum Power, Precision & Performance

Upgrade your BMX setup with the Promax HF‑2 Crankset combined with the SRM Spider PowerMeter — the ultimate solution for riders who demand uncompromising stiffness, world‑class power measurement, and race‑ready reliability. Engineered for explosive gate starts, consistent sprint performance, and long‑term durability, this system delivers industry leading accuracy in every pedal stroke.

Key Features at a Glance:

• Promax HF‑2 BMX Crankset – Ultra‑stiff, and designed for the high torque and power transfer of BMX!
• SRM Spider PowerMeter – Industry‑leading ±1% accuracy for professional‑grade performance tracking
• Compatible with 4‑bolt BMX chainrings (104 BCD) – CHAINRINGS NOT INCLUDED!
• 24 mm steel spindle
• Magnet‑less cadence measurement – Reliable data without external cadence magnets
• Long battery life – Up to 100 hours of ride time per charge

Maximum Stiffness for Explosive BMX Power

The Promax HF‑2 crankset is built for riders who push the limits. Its forged‑alloy arms deliver exceptional stiffness, ensuring that every watt you produce goes straight into forward motion — ideal for gate starts, sprints, and high‑torque BMX racing.

SRM Power Accuracy Trusted by Champions

The integrated SRM Spider PM 9 PowerMeter brings world‑renowned precision to your BMX bike. With ±1% accuracy, temperature compensation, and magnet‑less cadence detection, you get consistent, reliable data whether you’re training or racing.

SRM PowerMeter 9 – The Next Generation

SRM Spider PowerMeters are the Origin of mobile power measurement. Since 1986 we have continuously refined our PowerMeters to meet ever-higher standards in technology, accuracy and reliability. For that reason, our PowerMeters are widely seen as the Gold-Standard for training with power.

Our 9th generation Spider PowerMeter takes our proven formula and updates it with modern features. The result is a PowerMeter that is easier to use, even more accurate, longer-lasting, and has improved connectivity.

Thanks to a combination of angle and torque measurement, the PM9 is now able to measure with higher accuracy in very low cadence situations and oval chain-rings do no longer have an impact on the recorded data. The integrated temperature sensor allows for maximum accuracy in changing conditions. Users are now able to show L&R balance, as well as combined Pedal smoothness.

PowerMeter 9 comes with many usability improvements. First is the Magnet-less cadence mode, which allows you to use the PowerMeter without any cadence magnet.
PowerMeter 9 can be used with ANT+ and Bluetooth LE. It connects to pretty much any head unit and comes with a mobile App. The App gives you access to live torque data, battery status information, firmware updates, and much more.

The picture shown is for illustration purposes only. The actual product may vary due to product enhancement.