Boggy - 531pro and 531 SL are the same steel as all 531 frames but the thickness (guage) varies, these are the two lightest 531 tubesets (I think they are actually the same tubeset), but are quite delicate as a result and also relatively rare in good condition. 531 isn't all great, a plain guage 531 main tubes only, is gonna feel like a sack of potatoes compared to a full 531 pro or SL double butted frame.
at least some people know what there talking about
#20230
chaliapin
Boggy - 531pro and 531 SL are the same steel as all 531 frames but the thickness (guage) varies, these are the two lightest 531 tubesets (I think they are actually the same tubeset), but are quite delicate as a result and also relatively rare in good condition. 531 isn't all great, a plain guage 531 main tubes only, is gonna feel like a sack of potatoes compared to a full 531 pro or SL double butted frame.
at least some people know what there talking about