Frame Geometry Comparator
Overlay frame geometries to compare stack, reach, and angles.
- Tarmac SL8 · 54
- Roubaix SL8 · 54
Tarmac SL8 · 54 · stack 547 · reach 386 · 73.5°
Roubaix SL8 · 54 · stack 583 · reach 378 · 72.5°
| Measurement | Tarmac SL8 · 54 | Roubaix SL8 · 54 | Δ |
|---|---|---|---|
| Stack | 547 mm | 583 mm | +36 mm |
| Reach | 386 mm | 378 mm | -8 mm |
| Head tube angle | 73.5° | 72.5° | -1.0° |
| Seat tube angle (eff.) | 74.0° | 73.8° | -0.3° |
| Top tube (eff.) | 545 mm | 552 mm | +7 mm |
| Chainstay | 410 mm | 415 mm | +5 mm |
| BB drop | 70 mm | 75 mm | +5 mm |
| Fork rake | 44 mm | 47 mm | +3 mm |
| Head tube length | 155 mm | 195 mm | +40 mm |
| Seat tube length | 480 mm | 480 mm | 0 mm |
| Wheelbase calc. | 1,019 mm | 1,043 mm | +24 mm |
| BB height calc. | 269 mm | 268 mm | -1 mm |
| Trail calc. | 55 mm | 59 mm | +4 mm |
| Front-center calc. | 615 mm | 635 mm | +20 mm |
| Standover calc. | 816 mm | 851 mm | +35 mm |
How this works
Frame geometry is well-defined for the most part. Where conventions vary across brands — effective vs. actual seat tube angle, top tube length, BB drop vs. BB height — we fix a single convention and document it.
Trail is derived from head tube angle, fork rake, and wheel radius: trail = wheelRadius / tan(HTA) − rake / sin(HTA). Standover is geometrically approximated 300 mm forward of the BB and shown as (approx.). Manufacturer-published standover takes precedence when given.
Frame data is curated from each manufacturer's published geometry chart, cited in the database entry. If you spot a discrepancy, open a PR per the data contribution guide.
Full methodology at the full methodology on GitHub.