2026 TanTan Cycling (Seraph) GR257 Base
- Category
- Progressive Gravel
- Design
- Drop Bar, Rigid, non-suspension corrected
- Frame
- Carbon/Composite
- Fork
- Carbon/Composite
- Features
- Disc brake
Geometry
480 | 510 | 540 | 560 | 580 | 610 | |
Stack | 520mm | 540mm | 560mm | 580mm | 600mm | 620mm |
Reach | 363mm | 369mm | 376mm | 383mm | 390mm | 396mm |
Stack to Reach Ratio | 1.43:1 | 1.46:1 | 1.49:1 | 1.51:1 | 1.54:1 | 1.57:1 |
Seat Tube Length, C-TTT | 449mm | 488mm | 524mm | 546mm | 566mm | 589mm |
Top Tube Length, Effective/Horizontal Center | 510mm | 521mm | 540mm | 558mm | 575mm | 594mm |
Top Tube Slope | 8deg | 5.7deg | 4.1deg | 4deg | 4.1deg | 3.9deg |
Head Tube Angle | 70deg | 71deg | 71deg | 71deg | 71deg | 71deg |
Seat Tube Angle | 74.3deg | 74.3deg | 73.7deg | 73.3deg | 72.9deg | 72.3deg |
Head Tube Length | 86mm | 108mm | 132mm | 153mm | 177mm | 198mm |
Bottom Bracket Drop | 77mm | 72mm | 69mm | 69mm | 67mm | 67mm |
Bottom Bracket Height | 284mm | 289mm | 292mm | 292mm | 294mm | 294mm |
Chainstay Length | 435mm | 435mm | 435mm | 435mm | 435mm | 435mm |
Chainstay Length Horizontal | 428.1mm | 429mm | 429.5mm | 429.5mm | 429.8mm | 429.8mm |
Front-Center | 587.9mm | 593.4mm | 607.4mm | 621.4mm | 635.7mm | 648.7mm |
Front-Center Horizontal | 582.9mm | 589mm | 603.5mm | 617.5mm | 632.2mm | 645.2mm |
Wheelbase | 1011mm | 1018mm | 1033mm | 1047mm | 1062mm | 1075mm |
Fork Offset/Rake | 55mm | 55mm | 55mm | 55mm | 55mm | 55mm |
Fork Length, Unknown | 405mm | 405mm | 405mm | 405mm | 405mm | 405mm |
Trail | 72.9mm high | 66.1mm high | 66.1mm high | 66.1mm high | 66.1mm high | 66.1mm high |
Mechanical Trail | 68.5mm | 62.5mm | 62.5mm | 62.5mm | 62.5mm | 62.5mm |
Wheel Flop | 23.4mm | 20.4mm | 20.4mm | 20.4mm | 20.4mm | 20.4mm |
Tire to Pedal Spindle | 56.9mm 170 mm cranks | 62.4mm 170 mm cranks | 76.4mm 170 mm cranks | 90.4mm 170 mm cranks | 104.7mm 170 mm cranks | 117.7mm 170 mm cranks |
Pedal Spindle to Ground Clearance | 114mm 170 mm cranks | 119mm 170 mm cranks | 122mm 170 mm cranks | 122mm 170 mm cranks | 124mm 170 mm cranks | 124mm 170 mm cranks |
Base Build
480 | 510 | 540 | 560 | 580 | 610 | |
Wheel Size | 700C/29 in 622 mm BSD | 700C/29 in 622 mm BSD | 700C/29 in 622 mm BSD | 700C/29 in 622 mm BSD | 700C/29 in 622 mm BSD | 700C/29 in 622 mm BSD |
Tire Width | 50mm | 50mm | 50mm | 50mm | 50mm | 50mm |
Tire Width Max | 57mm | 57mm | 57mm | 57mm | 57mm | 57mm |
Tire Outer Diameter | 722mm | 722mm | 722mm | 722mm | 722mm | 722mm |
Bike Length with Tires | 1733mm | 1740mm | 1755mm | 1769mm | 1784mm | 1797mm |
Published Sizing Recommendations
PBH | 588 in to | 593 in to | 607 in to | 621 in to | 636 in to | 648 in to |
Stack and Reach vs. Category Trend
Very Upright
Somewhat Upright
Average
Somewhat Aggressive
Very Aggressive
The Bike Insights Upright/Aggressive scale is based on analysis of a bike’s proportions relative to similar sized bikes in the same category.
Learn more about the Upright/Aggressive ScaleCategory Trend
Progressive GravelSource:https://www.instagram.com/p/DZmvWCGjrQR/?igsh=MXV0dDBqdnFicmcwNg==