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 replacement warranty against bending, cracking and breaking