Quote:
Originally Posted by Peter P.
It's obvious that tube diameter is the dominant factor in constructing an adequately stiff frame. That's why the old Teledyne Titan frames were a failure; not just because they used commercially pure titanium but because they used standard tube diameters of the day, in order to accommodate commonly available components.
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Had the Teledyne Titan used thicker tube walls, it would have been just as stiff as the steel frames of the day - but it would have been just as heavy also.
Quote:
Originally Posted by Peter P.
But the difference in spring rate between steel and titanium remains. Steel has what is described as a "progressive" or linear spring rate; the more you flex it the more it applies a return force whereas titanium is more like a door; initially it is flexible but more suddenly reaches resistance. These qualities result in the ride characteristics of titanium. They can't completely be tuned out, only mitigated. That accounts for the differences in ride qualities between titanium and steel.
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I'm sorry, but this description is inaccurate. Steel and titanium are both linearly elastic below their yield points. The graph below shows the stress-strain curves of a variety of titanium alloys. Notice that below the yield point (where the metal starts becoming permanently deformed) they all behave linearly elastic (just like steel). There is nothing "magic" about the stress/strain properties of titanium in the normal working domain.
