2017 Brother Cycles Big Bro Base

	SM	MD	LG	XL
Stack	584mm	591mm	602mm	617mm
Reach	396mm	414mm	431mm	442mm
Stack to Reach Ratio	1.47:1	1.43:1	1.4:1	1.4:1
Seat Tube Length, C-T	406mm	457mm	508mm	559mm
Top Tube Length, Effective/Horizontal HT Top	575mm	595mm	615mm	630mm
Top Tube Slope	20.8deg	15.7deg	11.3deg	7.8deg
Head Tube Angle	70.5deg	71deg	71.5deg	71.5deg
Seat Tube Angle	73deg	73deg	73deg	73deg
Head Tube Length	95mm	100mm	110mm	125mm
Bottom Bracket Drop	60mm	60mm	60mm	60mm
Bottom Bracket Height	312mm	312mm	312mm	312mm
Chainstay Length	445mm	445mm	445mm	445mm
Chainstay Length Max	445mm	445mm	445mm	445mm
Chainstay Length Horizontal	440.9mm	440.9mm	440.9mm	440.9mm
Chainstay Length Horizontal Max	440.9mm	440.9mm	440.9mm	440.9mm
Front-Center	633.2mm	648.3mm	663.6mm	679.5mm
Front-Center Horizontal	630.4mm	645.5mm	660.9mm	676.9mm
Wheelbase	1071.3mm	1086.4mm	1101.8mm	1117.8mm
Wheelbase Max	1071.3mm	1086.4mm	1101.8mm	1117.8mm
Fork Offset/Rake	46mm	46mm	46mm	46mm
Trail	82.9mm very high	79.4mm high	76mm high	76mm high
Mechanical Trail	78.2mm	75.1mm	72mm	72mm
Wheel Flop	26.1mm	24.5mm	22.9mm	22.9mm
Standover Height	776mm	804mm	834mm	865mm
Tire to Pedal Spindle	91.3mm 170 mm cranks	106.3mm 170 mm cranks	121.6mm 170 mm cranks	137.6mm 170 mm cranks
Pedal Spindle to Ground Clearance	142mm 170 mm cranks	142mm 170 mm cranks	142mm 170 mm cranks	142mm 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:Bike Counterculture Geometry Database

Geometry