Parts shipped today to get this up and running. To my knowledge, after a fair amount of research including the dealer tech manual, all tubies on this one are from Reynolds, the 4 largest diameter ones are 853. Should work out pretty well...
853 Designer Select
The Poprad is built from round 853 Designer Select tubes. This tubeset combines an 853 main triangle with Reynolds 525 stays. 853 and 525 have the same modu- lus (stiffness), but 853 has a greater tensile strength. In the main triangle, the higher strength of 853 allows us to use thinner, lighter tubes. With the stays, there’s a limit on how thin the metal can be that’s not determined by strength, but weldable thickness.