Old 08-13-10, 04:02 PM
  #3  
miamijim
Senior Member
 
miamijim's Avatar
 
Join Date: Aug 2003
Location: Tampa, Florida
Posts: 14,110
Mentioned: 40 Post(s)
Tagged: 0 Thread(s)
Quoted: 413 Post(s)
Likes: 0
Liked 109 Times in 78 Posts
Stems become proportionatly longer as frame sizes increase because top tube lengths tend be shorter in relation to top tubes as bikes become bigger and vice versa. Body proportions increase as well, tall people have longer torso and longer arms. TT's are generaly a torso fit while stem lengths are generaly an arm length fit

As an example, 54 to 58 cm may be 'square' meaning that both the ST and TT are the same lengths: 54/54, 56/56 etc. Smaller frames are over sqaure, the ST are shorter than the TT: 48/50, 50/52. Bigger frames are under square meaning the ST is longer than the TT: 60/58, 62/60 etc. Because of this small frames need stems in the 60-90 range, mid size frames in the 90-110 range and big frames need stems in the 110-130 range.

Smaller frames: little seat post showing with short stems
Average frames: normal post showing (6 inches or so) with 90-110 stems
Big frames: alot of post showing with long stems
miamijim is offline