Powerblock - 20"x1.60"

The outer knobs
About half the length of the transition knobs, the outer knobs are designed for maximum compression and traction at lean angles greater than 25 degrees. Typicallynot needed during a clean race, but if things get messy, the outer knobs will keep tracking during aggressive maneuvering and cornering giving you every last bit of grip to get you across the finish line faster.

The centre row "Power Block"
During acceleration, heavy pedaling toorque is transferred to the centre tread zone of the rear tyre. If these centre knobs are too small or tall they will exhibit greater knob flex/compression and stick to the ground just a bit longer before take-off, robbing valuable energy (too much traction is not always a good thing) conversely if knobs are too big or short, the tyre may slip under heavy torque before regaining traction significantly slowing you down.

Each Power Block is proportionally sized to handle the torque without sticking and perfectly balanced with the proper height to minimise slipping all while retaining very low rolling resistance after take-off.

The transition knobs
Substtantially smaller than the centre blocks and in exact proportion to the centre blocks the transition knobs are designed to deform slightly at lean angles greater than 15 degrees. This knob deformation or compression is the rubber "sticking" to the ground which is akin to traction. They are positioned at 45 degree angle relative to the centre knobs to help maintain forward momentum during side-to-side transitions and cornering.