2026 TanTan Cycling (Seraph) GR257 Base 540
Build
700C/29 in × 50 mm
Insights
Somewhat upright stack and reach vs trend of progressive gravel bikes
Design deviates from other sizes of TanTan Cycling (Seraph) GR257
Stack and Reach vs. Category Trend
View all sizes
Geometry
| Stack | 560mm |
| Reach | 376mm |
| Stack to Reach Ratio | 1.49:1 |
| Seat Tube Length, C-TTT | 524mm |
| Top Tube Length, Effective/Horizontal Center | 540mm |
| Top Tube Slope | 4.1deg |
| Head Tube Angle | 71deg |
| Seat Tube Angle | 73.7deg |
| Head Tube Length | 132mm |
| Bottom Bracket Drop | 69mm |
| Bottom Bracket Height | 292mm |
| Chainstay Length | 435mm |
| Chainstay Length Horizontal | 429.5mm |
| Front-Center | 607.4mm |
| Front-Center Horizontal | 603.5mm |
| Wheelbase | 1033mm |
| Fork Offset/Rake | 55mm |
| Fork Length, Unknown | 405mm |
| Trail | 66.1mm high |
| Mechanical Trail | 62.5mm |
| Wheel Flop | 20.4mm |
| Tire to Pedal Spindle Distance With 170 mm cranks | 76.4mm |
| Pedal Spindle to Ground Clearance With 170 mm cranks | 122mm |
Base Build
| Wheel Size | 700C, 29 inch (622mm BSD) |
| Tire Width | 50mm |
| Tire Outer Diameter | 722mm |
| Bike Length with Tires | 1755mm |
| Suspension Type | Rigid, non-suspension corrected |
| Bar Type | Drop Bar |
| Frame Material | Carbon/Composite |
| Fork Material | Carbon/Composite |
| Brake Type | Disc |
Published Sizing Recommendations
| PBH | 607 in to |
Source:https://www.instagram.com/p/DZmvWCGjrQR/?igsh=MXV0dDBqdnFicmcwNg==