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 |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| 450 | 541 mm published | 375 mm published | 70.5 ° derived | 75.0 ° derived | 520 mm derived | 425 mm derived | 1011 mm derived | 596 mm published | 74 mm derived | 73.4 mm derived | 48 mm published | red |
| 2 of 3 checks flagged — Stack Reconciliation shows 10.9mm discrepancy | ||||||||||||
| 480 | 555 mm published | 386 mm published | 70.5 ° derived | 74.0 ° derived | 545 mm derived | 425 mm derived | 1026 mm derived | 612 mm published | 74 mm derived | 73.4 mm derived | 48 mm published | red |
| 2 of 3 checks flagged — Stack Reconciliation shows 11.1mm discrepancy | ||||||||||||
| 510 | 580 mm published | 397 mm published | 70.5 ° derived | 73.5 ° derived | 569 mm derived | 425 mm derived | 1047 mm derived | 632 mm published | 72 mm derived | 73.4 mm derived | 48 mm published | red |
| 2 of 3 checks flagged — Stack Reconciliation shows 9.5mm discrepancy | ||||||||||||
| 540 | 605 mm published | 408 mm published | 70.5 ° derived | 73.2 ° derived | 590 mm derived | 425 mm derived | 1066 mm derived | 652 mm published | 72 mm derived | 73.4 mm derived | 48 mm published | red |
| 2 of 3 checks flagged — Stack Reconciliation shows 10.9mm discrepancy | ||||||||||||
| 570 | 630 mm published | 419 mm published | 70.5 ° derived | 73.0 ° derived | 600 mm derived | 425 mm derived | 1075 mm derived | 660 mm published | 72 mm derived | 73.4 mm derived | 48 mm published | red |
| 2 of 3 checks flagged — Stack Reconciliation shows 11.4mm 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 Colnago C68 gravel geometry exhibits systematic discrepancies across all five sizes. Stack values are deflated by 9.5–11.4mm relative to the engine's forward-model calculations, representing significant data inaccuracies in the published specification. Reach shows data inaccuracies ranging from 2.6mm to 15.1mm across sizes 450–570mm, with the largest discrepancy on size 570. Front center reconciles within ±1mm engineering tolerance across all sizes. The manufacturer's published fork axle-to-crown length of 409mm is used directly by the engine — the stack discrepancies cannot be attributed to fork A2C and indicate a data inaccuracy in either the published stack values or the published head tube length values.