2025 Transition Bikes Sentinel Alloy
- Category
- Full-suspension Trail MTB
- Design
- Flat Bar, Full suspension
- Frame
- Aluminum
- Suspension
- 160mm fork travel, 150mm rear travel
- Features
- Disc brake
Average stack and reachvs category Suspension sag unknown Geometry may mis-represent actual riding geometry | Average stack and reachvs category Suspension sag unknown Geometry may mis-represent actual riding geometry | Average stack and reachvs category Suspension sag unknown Geometry may mis-represent actual riding geometry | Average stack and reachvs category Suspension sag unknown Geometry may mis-represent actual riding geometry | Average stack and reachvs category Suspension sag unknown Geometry may mis-represent actual riding geometry | Average stack and reachvs category Suspension sag unknown Geometry may mis-represent actual riding geometry |
Geometry
XS | SM | MD | LG | XL | XXL | |
Stack | 592mm | 615mm | 621mm | 633mm | 642mm | 651mm |
Reach | 415mm | 430mm | 455mm | 480mm | 505mm | 530mm |
Stack to Reach Ratio | 1.43:1 | 1.43:1 | 1.36:1 | 1.32:1 | 1.27:1 | 1.23:1 |
Seat Tube Length, C-T | 360mm | 360mm | 390mm | 430mm | 460mm | 490mm |
Top Tube Length, Effective/Horizontal HT Top | 534mm | 557mm | 586mm | 614mm | 642mm | 670mm |
Head Tube Angle | 64deg | 64deg | 64deg | 64deg | 64deg | 64deg |
Effective Seat Tube Angle, ETT HT Top | 79.2deg | 78.7deg | 77.9deg | 77.3deg | 76.8deg | 76.5deg |
Head Tube Length | 100mm | 100mm | 110mm | 120mm | 130mm | 140mm |
Bottom Bracket Drop | 15mm | 25mm | 25mm | 25mm | 25mm | 25mm |
Bottom Bracket Height | 338mm | 347mm | 347mm | 347mm | 347mm | 347mm |
Chainstay Length | 434mm | 442mm | 442mm | 446mm | 446mm | 446mm |
Chainstay Length Horizontal | 433.7mm | 441.3mm | 441.3mm | 445.3mm | 445.3mm | 445.3mm |
Front-Center | 737.4mm | 767.1mm | 796.1mm | 826.1mm | 855.1mm | 885.1mm |
Front-Center Horizontal | 737.3mm | 766.7mm | 795.7mm | 825.7mm | 854.7mm | 884.7mm |
Wheelbase | 1171mm | 1208mm | 1237mm | 1271mm | 1300mm | 1330mm |
Fork Offset/Rake | 37mm | 44mm | 44mm | 44mm | 44mm | 44mm |
Fork Length (Axle-To-Crown) | 560mm | 578mm | 578mm | 578mm | 578mm | 578mm |
Trail | 131mm very high | 132.5mm very high | 132.5mm very high | 132.5mm very high | 132.5mm very high | 132.5mm very high |
Mechanical Trail | 117.7mm | 119.1mm | 119.1mm | 119.1mm | 119.1mm | 119.1mm |
Wheel Flop | 51.6mm | 52.2mm | 52.2mm | 52.2mm | 52.2mm | 52.2mm |
Tire to Pedal Spindle | 214.5mm 170 mm cranks | 225.2mm 170 mm cranks | 254.1mm 170 mm cranks | 284.1mm 170 mm cranks | 313.1mm 170 mm cranks | 343.1mm 170 mm cranks |
Pedal Spindle to Ground Clearance | 168mm 170 mm cranks | 177mm 170 mm cranks | 177mm 170 mm cranks | 177mm 170 mm cranks | 177mm 170 mm cranks | 177mm 170 mm cranks |
Alloy Build
XS | SM | MD | LG | XL | XXL | |
Wheel Size | 650B/27.5 in 584 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 | 2.4in | 2.4in | 2.4in | 2.4in | 2.4in | 2.4in |
Tire Width Max | 2.5in | 2.5in | 2.5in | 2.5in | 2.5in | 2.5in |
Tire Outer Diameter | 705.9mm | 743.9mm | 743.9mm | 743.9mm | 743.9mm | 743.9mm |
Bike Length with Tires | 1876.9mm | 1951.9mm | 1980.9mm | 2014.9mm | 2043.9mm | 2073.9mm |
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
Full-suspension Trail MTBSource:https://www.transitionbikes.com/Bikes/Sentinel