Originally Posted by
Looigi
I remember back in '76 a friend of a friend in college showing us some of his fancy bike stuff including a Ti crank spindle. It was the first Ti I ever saw and got to heft. It was amazingly light. Back then they were breaking so fell into disfavor.
Back then the Ti used was "CP grade" (chemically pure) grade which is weaker and has a much poorer fatigue life than currently used 3Al/2.5V or 6Al/4V alloy. The Teledyne Titan, one of the first Ti bike frames, was made of CP-grade and had a well deserved reputation for breaking.
Even with the much stronger Ti alloys used today there are some recommended rider weight limits. Speedplay says their Ti axle pedals should be limited to a maximum of 185 pound rider weight.