S and S Machine
Bicycle Torque Couplings (BTCs)
Your Travel Bike........Your Only Bike!

 Bicycle Torque Coupling Destructive Testing Samples

This Reynolds 531 bicycle tube with a coupling installed in the butted section was twisted until the tube failed to verify the strength of the coupling. There was no sign of damage to the coupling. The test demonstrated that in torsion the BTC was actually stronger than the tube itself.

This Reynolds 531 bicycle tube with a coupling installed in the butted section was pulled apart as a test to verify the strength of the coupling. The coupling showed no sign of any damage. The test demonstrated that in tension a BTC is actually stronger than the tube itself.

How did the test sample stretch before it broke?

• Dimensions before: The sample was marked accurately at one inch increments before the test.
• Dimensions after: After the sample was broken it was measured and the new dimensions were recorded in the center column.
• Dimensional change: The change in distance between the marks is given in the right column.
• Total change in length: The overall tube stretched .559 inches before it broke.
• Results: There was no dimensional change in the coupling.

   Before             After  Change

Check out these bikes that were involved in accidents.

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