Originally Posted by
Carson Dyle
For what purpose?
The way to tell would be to find the Trek catalog for the model year of your bike (it should be online) and find their spec chart for the frame. From there, you should be able to compare measurements like that one and easily be able to tell which size Trek called it.
The purpose is that this bike fits me well and I want to know the frame size for when I get something new.
Finding an old Trek catalog can't be the only way to measure my frame size...can it?