The main sections of the museum are listed below;
Tools of the trade, some ways to investigate problems;
Dye penetrant testing
of materials engineering terms
Bicycle Component Failure
Seat post failure
Click on pictures below for
This aluminium alloy mountain bike seat
post failed at the point where it entered the steel frame. It
had been machined to size and the rider had marked the preferred
height setting with PVC tape as shown.
The combination of the damp conditions under the tape, the
machining marks and the galvanic cell produced from the aluminium
seat post and steel frame caused reverse-bend corrosion fatigue
to occur that enabled a crack to nucleate and grow so that
the remaining ligament could no longer support the applied
This photograph shows the machine marks
on the outer surface and to the rear of the photo the ductile failure
as the last material fractured.
The plan view of the fracture surface shows
the half moon corrosion fatigue crack at 9 o'clock and the fast
fracture surface it triggered.
to Bicycle components
Return to Corrosion