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Cranks / Thunderbolt w/Socket Drive

Current Colors

  • Rustproof Black

Thunderbolt w/Socket Drive

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.


  • 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


  • Socket Drive™ sprocket interface
  • 22mm spindle
  • 175mm only
  • RHD only
  • Black only

Socket Drive™ is a royalty-free interface. Please download the spec sheet for dimensions and tolerancing specifications here to produce your own Socket Drive™ sprockets.

Please note, these cranks will not work without a corresponding Socket Drive™ sprocket. We offer the Killington, La Guardia, and Tom Dugan Fang sprockets in Socket Drive™, and certain boutique brands already offer Socket Drive™ compatible options.


Click HERE to learn more about the Stampy test.