2021 Surly Bikes ECR 27+ Base

	XS	S	M
Stack	556mm	579.5mm	603mm
Reach	385mm	398mm	410.5mm
Stack to Reach Ratio	1.44:1	1.46:1	1.47:1
Seat Tube Length, C-T	346.4mm	406.4mm	457.2mm
Top Tube Length, Effective/Horizontal HT Top	555mm	575mm	595mm
Top Tube Length, Actual C-C	536.3mm	547mm	563.1mm
Top Tube Slope	24.8deg	20.3deg	16.9deg
Head Tube Angle	69deg	69deg	69deg
Seat Tube Angle	73deg	73deg	73deg
Head Tube Length	90mm	115mm	140mm
Bottom Bracket Drop	60mm	60mm	60mm
Bottom Bracket Height	308.2mm	308.2mm	308.2mm
Chainstay Length	435mm	435mm	435mm
Chainstay Length Horizontal	430.8mm	430.8mm	430.8mm
Front-Center	624.4mm	646mm	667.9mm
Front-Center Horizontal	621.5mm	643.2mm	665.2mm
Wheelbase	1052.3mm	1074mm	1096mm
Fork Offset/Rake	43.2mm	43.2mm	43.2mm
Fork Length (Axle-To-Crown)	447mm	447mm	447mm
Trail	95.1mm very high	95.1mm very high	95.1mm very high
Mechanical Trail	88.8mm	88.8mm	88.8mm
Wheel Flop	31.8mm	31.8mm	31.8mm
Standover Height	726mm	766mm	802mm
Tire to Pedal Spindle	86.2mm 170 mm cranks	107.8mm 170 mm cranks	124.7mm 175 mm cranks
Pedal Spindle to Ground Clearance	138.2mm 170 mm cranks	138.2mm 170 mm cranks	133.2mm 175 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://surlybikes.com/bikes/ecr

Geometry