A size-by-size geometry profile with manufacturer provenance and RideDNA consistency-audit context. Use the complete table to compare fit and handling before opening the interactive tools.
Source: Manufacturer geometry source
Provenance: published is present in the manufacturer data; derived is calculated by RideDNA; manual is a staff-entered reference rather than a manufacturer-chart value. “Not published” means the manufacturer did not provide a value for that size.
| Size | Stack | Reach | HTA | STA | ETT | Chainstay | Wheelbase | Front center | BB drop | Trail | Fork offset | Audit context |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| L | 590 mm published | 376 mm published | 71.5 ° derived | 73.5 ° derived | 561 mm derived | 437 mm derived | 1040 mm published | 617 mm published | 76 mm derived | 59.4 mm derived | 60 mm derived | red |
| 3 of 4 checks flagged — Reach Reconciliation shows 10.2mm discrepancy | ||||||||||||
| M | 570 mm published | 368 mm published | 70.5 ° derived | 73.5 ° derived | 547 mm derived | 437 mm derived | 1036 mm published | 612 mm published | 76 mm derived | 66.2 mm derived | 60 mm derived | red |
| 3 of 4 checks flagged — Reach Reconciliation shows 10.2mm discrepancy | ||||||||||||
| S | 547 mm published | 358 mm published | 69.1 ° derived | 73.5 ° derived | 529 mm derived | 437 mm derived | 1044 mm published | 620 mm published | 79 mm derived | 75.8 mm derived | 60 mm derived | red |
| 4 of 4 checks flagged — Reach Reconciliation shows 7.5mm discrepancy | ||||||||||||
| XL | 610 mm published | 384 mm published | 72.0 ° derived | 73.5 ° derived | 575 mm derived | 437 mm derived | 1050 mm published | 626 mm published | 74 mm derived | 56.0 mm derived | 60 mm derived | red |
| 3 of 4 checks flagged — Reach Reconciliation shows 10.3mm discrepancy | ||||||||||||
Overall consistency: red. This context is shown alongside the table so a rider can distinguish a complete published specification from a value that RideDNA had to derive or could not independently verify.
The 3T Extrema Italia geometry specification exhibits systematic discrepancies across all four sizes. Reach shows 7.5–10.3mm data inaccuracies across all sizes. Wheelbase and front center show 4.1–12.0mm discrepancies on sizes M–XL, with size S showing smaller 4.1–4.8mm discrepancies within or near engineering tolerance. Stack reconciles within ±1mm engineering tolerance on sizes M–XL, with size S showing a 4.9mm data inaccuracy. The forward model used Effective Top Tube (ETT) as the geometry anchor to determine BB horizontal position — reach and front center are both independently derived from this ETT-anchored BB position. The simultaneous systematic discrepancies in both reach and front center indicate a mutual inconsistency exists among the published ETT, reach, and front center values. The anomalous front center non-progression between sizes S (620mm) and M (612mm) — where the engine's calculated front center does not show the same decrease — provides independent evidence of a data integrity issue in the published front center and reach values, supporting confidence in the first-principles ETT-anchored geometry as the more reliable result.