2021 Sonder Vir Fortis Base

	Small	Medium	Large
Stack	586mm	595mm	614mm
Reach	406mm	423mm	437mm
Stack to Reach Ratio	1.44:1	1.41:1	1.41:1
Seat Tube Length, Unknown	406mm	457mm	505mm
Top Tube Length, Effective/Horizontal Unknown	580mm	605mm	625mm
Top Tube Slope	20.7deg	15.8deg	12.6deg
Head Tube Angle	68.5deg	68.5deg	68.5deg
Seat Tube Angle	73.5deg	73deg	73deg
Head Tube Length	100mm	110mm	130mm
Bottom Bracket Drop	60mm	60mm	60mm
Bottom Bracket Height	321.1mm	321.1mm	321.1mm
Chainstay Length	445mm	445mm	445mm
Chainstay Length Horizontal	440.9mm	440.9mm	440.9mm
Front-Center	664.8mm	684.7mm	706.6mm
Front-Center Horizontal	662.1mm	682.1mm	704.1mm
Wheelbase	1103mm	1123mm	1145mm
Fork Offset/Rake	45mm	45mm	45mm
Trail	101.8mm very high	101.8mm very high	101.8mm very high
Mechanical Trail	94.7mm	94.7mm	94.7mm
Wheel Flop	34.7mm	34.7mm	34.7mm
Tire to Pedal Spindle	113.7mm 170 mm cranks	133.6mm 170 mm cranks	155.5mm 170 mm cranks
Pedal Spindle to Ground Clearance	151.1mm 170 mm cranks	151.1mm 170 mm cranks	151.1mm 170 mm cranks

Published Sizing Recommendations

Height

5 ft 2 in

5 ft 7 in

5 ft 6 in

5 ft 10 in

5 ft 9 in

6 ft 2 in

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.

Category Trend

Source:https://alpkit.com/collections/sonder-vir-fortis/products/sonder-vir-fortis-gx-eagle