Thunderbolt

The Thunderbolt is the new and improved descendent of the Twombolt. It is still one of the most technically advanced crank designs on the market. Due to continued advancements in our legendary 41-Thermal® processing and heat-treatment system, fatigue life has been increased by a massive margin. Laboratory tested and team proven Updated open-ended spindle cap New wedge cluster band with greater flexibility Never-Wobble™ crank arm and spindle interface guarantee 41-Thermal® lifetime replace