2026 Principia Gravel 40 Base 51cm
Build
700C/29 in × 45 mm
Insights
Average stack and reach vs trend of all-road/gravel bikes
Stack and Reach vs. Category Trend
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Geometry
| Stack | 556.3mm |
| Reach | 377.5mm |
| Stack to Reach Ratio | 1.47:1 |
| Seat Tube Length, Unknown | 510mm |
| Top Tube Length, Effective/Horizontal Center | 537mm |
| Top Tube Slope | 7.3deg |
| Head Tube Angle | 70.5deg |
| Seat Tube Angle | 74deg |
| Head Tube Length | 135mm |
| Bottom Bracket Drop | 67mm |
| Bottom Bracket Height | 289mm |
| Chainstay Length | 435mm |
| Chainstay Length Horizontal | 429.8mm |
| Front-Center | 602.2mm |
| Front-Center Horizontal | 598.5mm |
| Wheelbase | 1028.3mm |
| Fork Offset/Rake | 45mm |
| Fork Length, Unknown | 400mm |
| Trail | 78.3mm high |
| Mechanical Trail | 73.8mm |
| Wheel Flop | 24.7mm |
| Tire to Pedal Spindle Distance With 170 mm cranks | 76.2mm |
| Pedal Spindle to Ground Clearance With 170 mm cranks | 119mm |
Base Build
| Wheel Size | 700C, 29 inch (622mm BSD) |
| Tire Width | 45mm |
| Tire Outer Diameter | 712mm |
| Bike Length with Tires | 1740.3mm |
| Crank Length | 170mm |
| Handlebar Width | 420mm |
| Stem Length | 90mm |
| Stem Angle | -7deg |
| Suspension Type | Rigid, non-suspension corrected |
| Bar Type | Drop Bar |
| Frame Material | Aluminum |
| Fork Material | Carbon/Composite |
| Brake Type | Disc |
Source:https://principiabikes.com/gravel/gravel-aluminium/gravel-40---bronze-pg-2588