Hyperpro produces rising spring rate springs where the first part can be easily compressed, and where compression of the last part is much harder. The front fork spring is designed to use the maximum front fork stroke, and to withstand heavy breaking so that it won't disturb the front grip.
Progressive springs are designed to provide:
* shorter braking distance
* better balance in the bike
* easy cornering
* improved tire life
* more grip in dry or wet weather