Hi Thomas,
Reynolds 708 was introduced in 1982 according to a flyer from TI
Reynolds, It has what was called variable strength technology.
The head-tube and fork parts are 531 mang-moly at 120,000 psi, the three
main tubes where of the same mang-moly but heat treated to 135,000 psi and
the stays are made of mang-moly but heat treated to 195,000 psi. The latter is what 753 was made of.
708 has 8 straight ribs on plain gauge through the three main tubes I built about 10 frames from it, I built one last year from my final set.
similar to Super Vitus TXO tubing, however the TXO had a 6 ribs down the
tubes and on top of the butts and had a strength 175,000-185,000 psi.
Super Vitus was a Chrom-moly-Vanadium steel and still is my favorite tubing to work with.
Columbus SLX/SPX had spiral ribs on the butts and TSX had spiral ribs through out the tubes, the psi was about 120,000. TSX was like a giant spring inside, in my humble opinion al it did was add weight.
Anthony
Mezzatesta Custom Cycles
Cranberry Twp. PA. 16066
http://www.mezzatestacustomcycles