Back in 95-96 or so I had an adroit (?19" - don't remember). It had a stock MC2 (?90mm long), but I felt like it was too short and was going to fall over the handlebars when going downhill. I ordered a new MC2 that was longer and had a higher rise, overall it seemed to fit me ok.
Fastforward to 2007, I ride a Kona Major Jake 56cm with a 90mm stem and top tube around 55cm as well. I'm surfing ebay for an old klein again because I miss it - but don't know what size I would need. The Klein site shows that S-small attitude frame has a top tube of 55cm but they list my height (6'1) as borderline L-XL. What's going on here?