I **_do not_** recommend paying attention to (listed) effective toptube.
Here is why:
First off, everyone should have their saddle set in a fore-aft position that works best for **_them_**. Not at the place where the bike designer _happened_ to put it.
That means that you adjust your saddle position to the same spot on every bike (for a certain use and style of riding).
Let’s take two imaginary bikes, with identical front centers (stack and reach and head angle). One has a steep seat tube angle, one has a slack seat tube angle. Effective toptube will be much longer on the second bike. But when you buy either of the two bikes, you would adjust your saddle position so it ended up the same distance behind the bottom bracket. The seated reach to the bars would be identical.
The thing that **_is_** important is **_effective seat tube angle_**. To see whether it is at all possible to get your saddle in **_your preferred position_**. Unfortunately, it is impossible to calculate effective seat tube angle at your own saddle height, based off the info in a geometry chart.
May 28, 2019, 7:23 a.m. - Tjaard Breeuwer
I **_do not_** recommend paying attention to (listed) effective toptube. Here is why: First off, everyone should have their saddle set in a fore-aft position that works best for **_them_**. Not at the place where the bike designer _happened_ to put it. That means that you adjust your saddle position to the same spot on every bike (for a certain use and style of riding). Let’s take two imaginary bikes, with identical front centers (stack and reach and head angle). One has a steep seat tube angle, one has a slack seat tube angle. Effective toptube will be much longer on the second bike. But when you buy either of the two bikes, you would adjust your saddle position so it ended up the same distance behind the bottom bracket. The seated reach to the bars would be identical. The thing that **_is_** important is **_effective seat tube angle_**. To see whether it is at all possible to get your saddle in **_your preferred position_**. Unfortunately, it is impossible to calculate effective seat tube angle at your own saddle height, based off the info in a geometry chart.