size of bike

[ray-ray]

i am still very new to the cycling thing and have a few questions.where or what do u mesure on a bike to get its size. example my bike is a 51cm and my mate's bike is 58cm, but when u put them next to each other the handels and seat is the same hight?

[The Saint]

When I Look for a bike size to fit me I always measure the effective top tube length (center to center). Some manufacturers use this as the bike size others use the length from the Seat Tube to the bottom bracket. Some manufacturers just have their own idea about sizing.

[AndreZA]

And don't forget, a 51cm compact is not much smaller then a 58cm traditional frame.

[MTB_Roadie]

And don't forget, a 51cm compact is not much smaller then a 58cm traditional frame.

 

haha!

[AndreZA]

haha!

 

Why are you laughing? My current 52cm compact is actually bigger then what my 56cm standard frame was.

[MTB_Roadie]

Why are you laughing? My current 52cm compact is actually bigger then what my 56cm standard frame was.

 

I think compact bikes get measure in different ways....like my medium the top tube is 55.7, seat stay is 48cm...guess it depends on the frame manufacturer? I think what he meand the handle bars and saddle is the same height, however the one bike will be a bit longer than the other one...