Thunder Crank Technology

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Our Performance Experience is YOUR Performance Edge!

Top Fuel Drag Racing is one of the most abusive forms of racing. Over a hundred times more stress is placed upon the components.

R&B Cycles realized through experience that the need to replace complete flywheel assemblies after one or two races was impractical, time consuming and outrageously expensive. John "Red" Rhea, owner, found that the tapers on the shafts of conventional, OEM-style flywheel assemblies would either distort or actually break after being subjected to continued stress of Top Fuel competition. There had to be a better way!


Available Pinion Shaft Designs:
  1) Stock Length Big Twin
  2) .375 Extended Big Twin
  3) 4 Cam Delkron
R&B Cycles has developed a revolutionary new crankshaft for Harley Davidson Motorcycles (Thunder Crank) utilizing a hex design on the shafts and crankpin to lock everything Rock Solid. Every piece of this crankshaft is made from high strength billet steel with a very tight machining tolerance of less than .0005", then heat treated. The current design uses a 1.500 diameter crankpin with a press on race made of 52-100 bearing steel and then heat treated.

Thunder Crank
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When the Thunder Crank is assembled it can not be shifted or moved. "It is made true to stay true no matter what!"

Over the last several years of performance testing in the 1997 ADBA National Champion Pro Dragster machine, and our own Music City Warrior Pro Fuel bike, we have experienced zero failures while using the same crankshaft assembly in each dragster! These Thunder Crank assemblies are still in use and still in true! In both of the aforementioned racing programs, crankshaft crankshaft assembly maintenance has been cut by 80%!

Our Thunder Crank are available in strokes from 4 1/4" to 5 1/4". This will work in all racing and big inch enginesusing Big Twin crankshafts. We are currently working a street version for use with the 1 1/4" (stock size) crankpin and rod setup.

For more information about these products as well as other services give us a call or come by and see us.

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