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.
Our Socket Drive™ interface system has been in use on our FLATWARE CRANKS since their inception, and it was only a matter of time before the system was adapted into our THUNDERBOLT cranks. The time has come.
In a nutshell, the Socket Drive™ system is a 9 sided interface which eliminates the need for a sprocket bolt. The sprocket itself is machined so there is no need for a sprocket insert of any kind. The two work great together.