	XS	S	M	L	XL	XXL
Stack	580mm	600mm	625mm	650mm	680mm	710mm
Reach	350mm	365mm	380mm	395mm	410mm	425mm
Stack to Reach Ratio	1.66:1	1.64:1	1.64:1	1.65:1	1.66:1	1.67:1
Seat Tube Length, C-T	355mm	416mm	453mm	483mm	533mm	563mm
Top Tube Length, Effective/Horizontal HT Top	521mm	547mm	568mm	590mm	614mm	644mm
Top Tube Slope	28.1deg	22.6deg	20.6deg	19.4deg	16.8deg	16.2deg
Head Tube Angle	69.5deg	69.5deg	70deg	70.5deg	70.5deg	71deg
Seat Tube Angle	74deg	73.5deg	73.5deg	73.5deg	73.5deg	73deg
Head Tube Length	107mm	128mm	151mm	176mm	208mm	237mm
Bottom Bracket Drop	80mm	80mm	80mm	80mm	80mm	80mm
Bottom Bracket Height	269mm	269mm	269mm	269mm	269mm	269mm
Chainstay Length	440mm	440mm	440mm	440mm	440mm	440mm
Chainstay Length Horizontal	432.7mm	432.7mm	432.7mm	432.7mm	432.7mm	432.7mm
Front-Center	597mm	619mm	637mm	656mm	681mm	700mm
Front-Center Horizontal	591.3mm	614.3mm	632.3mm	651.3mm	676.3mm	695.3mm
Wheelbase	1024mm	1047mm	1065mm	1084mm	1109mm	1128mm
Fork Offset/Rake	51mm	51mm	51mm	51mm	51mm	51mm
Fork Length (Axle-To-Crown)	395mm	395mm	395mm	395mm	395mm	395mm
Trail	76mm high	76mm high	72.8mm high	69.5mm high	69.5mm high	66.2mm high
Mechanical Trail	71.2mm	71.2mm	68.4mm	65.5mm	65.5mm	62.6mm
Wheel Flop	24.9mm	24.9mm	23.4mm	21.9mm	21.9mm	20.4mm
Standover Height	703.3mm	748.3mm	780.5mm	807.1mm	847.7mm	872.5mm
Tire to Pedal Spindle	78mm 170 mm cranks	100mm 170 mm cranks	118mm 170 mm cranks	137mm 170 mm cranks	162mm 170 mm cranks	181mm 170 mm cranks
Pedal Spindle to Ground Clearance	99mm 170 mm cranks	99mm 170 mm cranks	99mm 170 mm cranks	99mm 170 mm cranks	99mm 170 mm cranks	99mm 170 mm cranks

	XS	S	M	L	XL	XXL
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	38mm	38mm	38mm	38mm	38mm	38mm
Tire Width Max	45mm	45mm	45mm	45mm	45mm	45mm
Tire Outer Diameter	698mm	698mm	698mm	698mm	698mm	698mm
Bike Length with Tires	1722mm	1745mm	1763mm	1782mm	1807mm	1826mm
Stem Length	60mm	70mm	80mm	90mm	100mm	110mm

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

2026 Specialized Bicycles Sirrus X 5.0 - Carbon "Compliance Junction" Frame

Geometry