TheGravelBikeGeometryProject
  • Gravel Style
    • A table of gravel styles
    • The Gravelverse
    • What makes a racy frame racy?
    • What makes a relaxed frame relaxed?
    • What makes a rowdy frame rowdy?
    • Gravel Tree
  • Gravel Compare
    • Specs Comparison Tool
  • Gravel Geometry
    • Gravel Geometry
  • Gravel Suspension
    • How does a suspension fork change bike geometry – Tables of data
    • How does a suspension fork change bike geometry – Plots of data
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How does a suspension fork change bike geometry – Tables of data

How to search for a specific model and size!
  1. Use the pop-up box at the upper-left to search for a specific bike model and size.
  2. If there is already a model in the pop-up box then
  1. click in the box
  2. hit the delete key
  3. start typing model name.
Tip

More notes at the bottom!

function filter_default() {
    document.getElementById("Model").getElementsByClassName("selectized") 
[0].selectize.setValue("3T Extrema Italia 2025", false);
 }
window.onload = filter_default;
Note

The suspension fork length and geometry is based on 20% sag: fork_length - 0.2*travel

A Rudy Fork geometry corrector

Rockshox recommends 5% sag on the Rudy fork while Fox, Cane Creek, and Lauf recommend (or are tuned for) 20% sag. The sus geometry for a 30 mm Rudy fork will be about 1/2 way between the 30 mm and 40 mm measures (for the same offset). The sus geometry for a 40 mm Rudy fork will be about 3/5 way between the 40 mm and 50 mm measures (for the same offset).

Is your frame suspension corrected?

Several companies are calling their frame suspension corrected, or sell a suspension fork with a build, but their rigid Axle-Crown length is far short (by > 10 mm and often > 15 mm) the sagged length of a 30 mm fork.

Gravel forks
  1. Cane Creek Invert has two models: 30 mm (425 mm axle-crown) and 40 (435 mm axle-crown) mm travel. Both models have 45 mm offset
  2. Rockshox Rudy has four models: 30 mm (425 mm axle-crown) and 40 (435 mm axle-crown) mm travel, each with either 45 mm or 51 mm offset.
  3. Fox 32 TC Factory has four models: 40 (435.5 mm axle-crown) mm and 50 (445.5 mm axle-crown) mm travel, each with either 45 mm or 50 mm offset.
  4. Lauf has one model with 30 mm travel (425 Axle Crown and 47 mm offset)