Joined: Jul 2007
Posts: 5,045
Likes: 15
From: Lancaster County, PA
Bikes: '39 Hobbs, '58 Marastoni, '73 Italian custom, '75 Wizard, '76 Wilier, '78 Tom Kellogg, '79 Colnago Super, '79 Sachs, '81 Masi Prestige, '82 Cuevas, '83 Picchio Special, '84 Murray-Serotta, '85 Trek 170, '89 Bianchi, '90 Bill Holland, '94 Grandis
On very large Paramounts (over 26-in.) from the 70's, 4130 Chrome-Moly was used for the seattube and downtube. That was straight gauge, and not relevant to the bike the OP is referencing. But thought I'd toss it in FYI.