Ok,

I want to build up a steel frame. I have a 97 GT TT frame that I bought $650 worth of parts for (plus I have to get prolly another $200 to spec out everything).. then realized that it might not make sense to build on such an old frame. Anyway, I was looking at the Jamis line ... Anyone know what, exactly, is the difference between the 853-631-520-etc steel is? is it primarily weight? I don't really care about shaving 1 or 2 lbs .. I"m more interested in flexibility (I like springy) and strength. I'm also concerned about $$ cuz I'm already spendin way too much (my wife is going to start making me sleep with my bikes).

thanx,

Brian

This is all info that I gathered over the net:

520 is used because of its ability to be tig welded, thus producing lower cost (and lower quality) frame.

Reynolds 631 Air Hardened tubing is based on 853 Air Hardened technology. The main difference between the two is that the 853 is heat treated and the 631 is not.

Reynolds 853 tubing is superior for many reasons. It is a high strength, 210,000 PSI, heat treated, air hardened steel alloy. The wall thickness of 853 is only 0.4mm (0.1 mm thinner than Reynolds other top of the line 753 tubing). This is why 853 is lighter. 853 is a hard alloy that resists denting extremely well. 853 is also stiffer which means superior power transmission.

Hope this helps answer your question.