2025 Brother Cycles Stroma Base

	XS	Small	Medium	Large	XL
Stack	532mm	550mm	563mm	585mm	604mm
Reach	369mm	377mm	385mm	393mm	402mm
Stack to Reach Ratio	1.44:1	1.46:1	1.46:1	1.49:1	1.5:1
Seat Tube Length, C-T	500mm	520mm	540mm	560mm	580mm
Seat Tube Length, C-C	510mm	526mm	542mm	557mm	572mm
Top Tube Length, Effective/Horizontal Center	522mm	540mm	557mm	572mm	587mm
Top Tube Slope	5.8deg	5.6deg	4.9deg	5.1deg	4.9deg
Head Tube Angle	71deg	72deg	72.5deg	72.5deg	72.5deg
Seat Tube Angle	74deg	73.5deg	73deg	73deg	73deg
Head Tube Length	110mm	125mm	140mm	160mm	180mm
Bottom Bracket Drop	70mm	70mm	70mm	70mm	70mm
Bottom Bracket Height	279mm	279mm	279mm	279mm	279mm
Chainstay Length	420mm	420mm	420mm	420mm	420mm
Chainstay Length Horizontal	414.1mm	414.1mm	414.1mm	414.1mm	414.1mm
Front-Center	580.1mm	585.1mm	592mm	606.9mm	621.8mm
Front-Center Horizontal	575.9mm	580.9mm	587.9mm	602.9mm	617.9mm
Wheelbase	990mm	995mm	1002mm	1017mm	1032mm
Fork Offset/Rake	45mm	45mm	45mm	45mm	45mm
Fork Length (Axle-To-Crown)	381mm	381mm	381mm	381mm	381mm
Trail	72.6mm high	66.1mm high	62.9mm mid/neutral	62.9mm mid/neutral	62.9mm mid/neutral
Mechanical Trail	68.6mm	62.9mm	60mm	60mm	60mm
Wheel Flop	22.3mm	19.4mm	18mm	18mm	18mm
Tire to Pedal Spindle	61.1mm 170 mm cranks	66.1mm 170 mm cranks	73mm 170 mm cranks	87.9mm 170 mm cranks	102.8mm 170 mm cranks
Pedal Spindle to Ground Clearance	109mm 170 mm cranks	109mm 170 mm cranks	109mm 170 mm cranks	109mm 170 mm cranks	109mm 170 mm cranks

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://www.brothercycles.com/shop/frames/stroma-2025/

Geometry