Originally Posted by
The Golden Boy
With Trek- Until 1986- the "600" series bikes had a 531 main triangle and depending on year/model- the fork and stays would be made of 501, Mangalloy, Ishiwata... in 86, the lower mid-range bikes got the 531 main triangle with Tange CrMo forks and stays and the mid-mid range bikes got the 531/501 mix.
I'm not exactly sure how it played out for Tenax-
In any case- I think the concept more points to a more stronger bike at the expense of weight than out of price consideration.
I thought the whole point of using higher grade tubing is that you get could the same strength at a lower weight? I also suspect that decision to use 3 main tubes 531 and/or columbus tretubi was a good marketing tool (since the main triangle was made of a high grade steel) and a way of making the bike less expensive.
Not knocking tretubi or R531 main triangle bikes as many great riding bikes were made this way. One of my favorite bikes was a Pug PKN 10 which had a Reynolds 531 main triangle and I believe high tensile steel fork and rear triangle.