Principia Gravel: geometry and sizes
Principia may sell more than one frame under the Gravel name, each with its own geometry. These are the ones in the database. Each shows stack and reach for the smallest and largest size. The numbers for every size are on the model page.
The tables show the smallest and largest size, each with stack / reach in millimetres. Both terms are explained in the glossary.
Current Principia Gravel versions
| Version | Smallest | Largest |
|---|---|---|
| Gravel 20 2026 gravel · aluminium | 45 · 575.8 / 397.3 | 61 · 663.9 / 410.9 |
| Gravel 22TiTAN 2026 gravel · titanium | 50 · 550 / 363 | 58 · 623 / 398 |
| Gravel 30 2026 gravel · aluminium | 48 · 557 / 366.3 | 59 · 642.8 / 400.2 |
| Gravel 40 2026 gravel · aluminium | 48 · 533.6 / 373 | 59 · 619 / 407 |
| Gravel C20 2026 gravel · carbon | 50 · 581.5 / 369.6 | 56 · 628.3 / 396.5 |
The same size label on two versions doesn’t mean the same frame. And stack and reach only describe the frame: where the bars end up also depends on the stem, spacers and bars.
There’s no sizing by height here. Everything starts from your position. Enter your position and I’ll work out which versions and sizes match it.