Road Bike, Cycling Forums banner

1 - 4 of 4 Posts

·
Registered
Joined
·
10 Posts
Discussion Starter · #1 ·
I'm looking at an 05 Trek Madone 5.9 frameset. The drop-out is stamped 58, but when I measure from either the centre of the crank to the top of the seat-tube or from the centre of the seat tube to the centre of the steerer tube, both measure 56cm. This seems odd. Is the 58 stamp represent frame size and if so why do the actual measures differ?
 

·
Registered
Joined
·
1,222 Posts
Did you include the height of the seattube collar clamp? If you didn't, that's the answer. If you did, then something is wrong.
 

·
Registered
Joined
·
10 Posts
Discussion Starter · #3 ·
The seattube collar clamp is pretty much flush with the seattube. So I measured from the top of the seattube to the centre of the crank. If I measure from the centre of where the toptube intersects with the seattube, it is less than 56cm. From the top of the seattube to the centre of the crank is exactly 56cm. The dropout is definately marked 58cm though. Could it be a stamp mistake by Trek or is 58 a number that is both on the 56 and 58cm frame? If it's 56cm, it's exactly what I need. It seems to fit right. I'm 5 ft 11.
 

·
Registered
Joined
·
1,876 Posts
chamel said:
The seattube collar clamp is pretty much flush with the seattube. So I measured from the top of the seattube to the centre of the crank. If I measure from the centre of where the toptube intersects with the seattube, it is less than 56cm. From the top of the seattube to the centre of the crank is exactly 56cm. The dropout is definately marked 58cm though. Could it be a stamp mistake by Trek or is 58 a number that is both on the 56 and 58cm frame? If it's 56cm, it's exactly what I need. It seems to fit right. I'm 5 ft 11.
What you've got there is a 56. Center of crank spindle to top of seat tube (including the extension above the top tube) is the correct way to measure a Trek, clamp doesn't matter.
BTW, Lance Armstrong is 5' 10" and rides a 58 cm Trek.
The problem with fitting a race style Trek is the short, steep head tube and high bottom bracket can cause a lot of drop from the top of saddle to top of handlebar, especially if you are long legged.

Al
 
1 - 4 of 4 Posts
Top