Bike Forums - View Single Post - Frame size measuring

06-16-25 | 09:34 AM

#3

13ollocks

Senior Member

Joined: Oct 2023

Posts: 1,128

Likes: 1,002

Bikes: *'00 LS Vortex/Chorus 12/Campag Zondas*98 LS Classic - S&S couplers/Chorus 12/Rolf Vector Pros*'95 DeBernardi Cromor S/S, Mavic Open Pros on Phil Wood track hubs*

Quote:

Originally Posted by _ForceD_

I just obtained a (free $$) road bike. It’s a TREK 1200 (not sure of the year). It has a sloping top tube. I want to be sure of the frame size, but not sure how to measure bikes with sloping TTs (most of my bikes are old with horizontal TTs). In looking for ways to measure, I’m seeing the phrase “effective top tube,” but not a complete explanation. Would that be a level (imaginary) line from the top of the head tube to the seat post? (Then measure from that point on the seat tube down to the center of the BB?) — Dan

That's exactly what it is- an imaginary horizontal line from the center* of the head tube/top tube junction to the center of the seatpost.
*maybe from the top of the top tube/center of the head tube? Not sure that it's make a huge difference to the actual numerical measurement

Reply

0