2018-2019 Ritchey Design Ultra Base M (17.5")
Build
650B/27.5 in × 2.8 in
Insights
Average stack and reach vs trend of hardtail cross-country mtb bikes
Suspension sag unknown
Geometry may mis-represent actual riding geometry
Stack and Reach vs. Category Trend
View all sizes
Geometry
| Stack | 612.6mm |
| Reach | 430mm |
| Stack to Reach Ratio | 1.42:1 |
| Seat Tube Length, C-T | 432mm |
| Top Tube Length, Effective/Horizontal Center | 606.3mm |
| Top Tube Slope | 19.8deg |
| Head Tube Angle | 68.5deg |
| Seat Tube Angle | 74deg |
| Head Tube Length | 105mm |
| Bottom Bracket Drop | 58mm |
| Bottom Bracket Height | 305.1mm |
| Chainstay Length | 439mm |
| Chainstay Length Horizontal | 435.2mm |
| Front-Center | 705.6mm |
| Front-Center Horizontal | 703.3mm |
| Wheelbase | 1138.4mm |
| Fork Offset/Rake | 51mm |
| Fork Length (Axle-To-Crown) | 507mm |
| Trail | 88.2mm very high |
| Mechanical Trail | 82.1mm |
| Wheel Flop | 30.1mm |
| Standover Height | 771.3mm |
| Tire to Pedal Spindle Distance With 170 mm cranks | 172.5mm |
| Pedal Spindle to Ground Clearance With 170 mm cranks | 135.1mm |
Base Build
| Wheel Size | 650B, 27.5 inch (584mm BSD) |
| Tire Width | 2.8in |
| Tire Outer Diameter | 726.2mm |
| Bike Length with Tires | 1864.6mm |
| Suspension Type | Hardtail (Front suspension) |
| Bar Type | Flat Bar |
| Fork Travel | 120mm |
| Suspension Sag | Unknown |
| Frame Material | Steel |
| Fork Material | N/A |
| Brake Type | Disc |
Source:https://us.ritcheylogic.com/media/itm/magb1/Productfiles/97450008005/ritchey-ultra-geometry-1218.pdf