2021 Decathlon RockRider ST 900 Medium
Build
650B/27.5 in × 2.1 in
Insights
Average stack and reach vs trend of hardtail trail mtb bikes
Suspension sag unknown
Geometry may mis-represent actual riding geometry
Stack and Reach vs. Category Trend
View all sizes
Geometry
| Stack | 610mm |
| Reach | 402mm |
| Stack to Reach Ratio | 1.52:1 |
| Seat Tube Length, Unknown | 432mm |
| Top Tube Length, Effective/Horizontal Unknown | 588mm |
| Top Tube Slope | 20.4deg |
| Head Tube Angle | 69.5deg |
| Seat Tube Angle | 73deg |
| Head Tube Length | 124mm |
| Bottom Bracket Drop | 43mm |
| Bottom Bracket Height | 302.3mm |
| Chainstay Length Horizontal | 430mm |
| Front-Center | 662.4mm |
| Front-Center Horizontal | 661mm |
| Wheelbase | 1091mm |
| Fork Offset/Rake | 44mm |
| Trail | 82.1mm very high |
| Mechanical Trail | 76.9mm |
| Wheel Flop | 27mm |
| Tire to Pedal Spindle Distance With 170 mm cranks | 147.1mm |
| Pedal Spindle to Ground Clearance With 170 mm cranks | 132.3mm |
ST 900 Build
| Wheel Size | 650B, 27.5 inch (584mm BSD) |
| Tire Width | 2.1in |
| Tire Outer Diameter | 690.7mm |
| Bike Length with Tires | 1781.7mm |
| Handlebar Width | 720mm |
| Stem Length | 80mm |
| Suspension Type | Hardtail (Front suspension) |
| Bar Type | Flat Bar |
| Fork Travel | 120mm |
| Suspension Sag | Unknown |
| Frame Material | Aluminum |
| Fork Material | Steel |
| Brake Type | Unknown |
Published Sizing Recommendations
| Height | 165 cm to 174 cm |
Source:https://www.decathlon.it/p/mtb-st-900-27-5/_/R-p-301098?mc=8500763&c=GRIGIO