Place the end of a tape measure at the exact center point of the gear crank (the metal post that runs through the center of the bike's chain sprocket). Then run the tape measure up to the top of the tube. Measure to the point where the tube ends. This will give you the length of the seat tube which is the frame size.
Height Bike Size Road Bike Size
------------------------- --------- --------------
5'1” – 5'4” 155 – 163 cm XS 48 cm
5'4” – 5'7” 163 – 170 cm S 51 cm
5'7” – 5'10” 170 – 178 cm M 54 cm
5'10” – 6'0” 178 – 183 cm L 56 cm
What size is large frame bike?
0 1 2
------ ---------- ----------------------------
17-18" Medium 5' 6" - 5' 10" (168 - 178cm)
19-20" Large 5' 10" - 6' 1" (178 - 185cm)
21-22" X Large 6' 1" - 6' 4" (185 - 193cm)
23-24" XX Large 6' 4" - 6' 6" (193 - 198cm)
Road Bikes
What height bike should I get for my height?
What wheel size bike should I get for my height?
If you are 5'7” to 5'11” and have an inseam length of 29” to 31” then you should be looking for a bike frame size of 17 to 19 inches which is a Medium descriptive size. If you are 5'11” to 6'2” or have an inseam length of 31” to 33” then you need a bike frame size that is 19 to 21 inches.