Originally Posted by
mikestr
It's a reasonable hypothesis; one could add the growing interest in criterium racing at the time, for which steeper front ends were considered advantageous. But can we be certain that all PX10s during this period had this geometry? The question here is about the smaller frames having such long TTs; do we see this equally for the E and LX versions, for example? During this period the LX (or L in Europe) was stated to be the "team replica" model; was this only a question of componentry or was the frame geometry different?
I'm not sure it's relevant at this point, but I'm still confused by your statements concerning your bike or bikes. You mentioned a 60cm frame with a 58.5 cm TT; now it's a 56cm with a 57cm TT. Are there two bikes, both PX10E?
Yes, I have two of the PX10's from the 1973-1975 era, a 56cm and a 60cm. Both have similar measured angles, but different lug styles. The 56cm is a PX10E and the 60cm is a PX10LE.
Both are pictured about 8 or nine posts up from here (
not the post showing my later white 1979 PX10 and red 1985 PH501).
It would be mildly interesting as to what top tube length that 58cm or smaller than 54cm versions of these bikes had, I just don't have the data points.