Joined: Jan 2009
Posts: 44,345
Likes: 6,643
From: New York, NY, and High Falls, NY, USA
Bikes: 1962 Rudge Sports, 1971 Raleigh Super Course, 1971 Raleigh Pro Track, 1974 Raleigh International, 1975 Viscount Fixie, 1982 McLean, 1996 Lemond (Ti), 2002 Burley Zydeco tandem
Grim, mang-alloy is manganese molybdenum carbon steel, which is what Reynolds 531 is made of. As far as I know, it's functionally equivalent to chro-moly. It's about the same strength, so you can make it thin walled for lightness. I don't know if Tsunoda (the maker of Lotus) made it thin-walled, though.