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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 470 | 486 mm published | 379 mm published | 70.5 ° derived | 74.5 ° derived | 514 mm derived | 410 mm derived | 982 mm published | 579 mm published | 58 mm derived | 75.1 mm derived | 43 mm published | green |
| All 4 consistency checks passed | ||||||||||||
| 500 | 494 mm published | 387 mm published | 71.5 ° derived | 74.5 ° derived | 524 mm derived | 410 mm derived | 983 mm published | 581 mm published | 58 mm derived | 68.8 mm derived | 43 mm published | green |
| All 4 consistency checks passed | ||||||||||||
| 530 | 520 mm published | 386 mm published | 72.0 ° derived | 74.0 ° derived | 535 mm derived | 410 mm derived | 984 mm published | 582 mm published | 68 mm derived | 65.6 mm derived | 43 mm published | green |
| All 4 consistency checks passed | ||||||||||||
| 550 | 536 mm published | 391 mm published | 72.5 ° derived | 73.5 ° derived | 550 mm derived | 410 mm derived | 988 mm published | 588 mm published | 68 mm derived | 62.4 mm derived | 43 mm published | green |
| All 4 consistency checks passed | ||||||||||||
| 570 | 552 mm published | 397 mm published | 73.0 ° derived | 73.5 ° derived | 560 mm derived | 412 mm derived | 996 mm published | 593 mm published | 68 mm derived | 59.3 mm derived | 43 mm published | green |
| All 4 consistency checks passed | ||||||||||||
| 590 | 571 mm published | 400 mm published | 73.0 ° derived | 73.0 ° derived | 575 mm derived | 412 mm derived | 1005 mm published | 603 mm published | 68 mm derived | 59.3 mm derived | 43 mm published | green |
| All 4 consistency checks passed | ||||||||||||
Overall consistency: green. 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 Bianchi Specialissima's published geometry reconciles within ±1mm engineering tolerance across all six sizes for stack, reach, wheelbase, and front center. The forward-model calculations confirm internal consistency between the manufacturer's published effective top tube, reach, and front center specifications. The RideDNA Geometry Engine reconciliation analysis identifies a systematic stack mispublishing pattern: the published stack values appear inflated by approximately 1.2mm relative to what the other published geometry parameters imply, as evidenced by the co-firing of the head tube length and fork A2C back-calculation checks across all sizes.