2021 Surly Bikes ECR 29+ Base

	M	L	XL
Stack	609.5mm	633mm	656.5mm
Reach	408mm	420.5mm	433mm
Stack to Reach Ratio	1.49:1	1.51:1	1.52:1
Seat Tube Length, C-T	457.2mm	507.9mm	558.7mm
Top Tube Length, Effective/Horizontal HT Top	600mm	620mm	640mm
Top Tube Length, Actual C-C	560.5mm	580mm	600mm
Top Tube Slope	17.6deg	14.5deg	11.6deg
Head Tube Angle	70deg	70deg	70deg
Seat Tube Angle	72.5deg	72.5deg	72.5deg
Head Tube Length	100mm	125mm	150mm
Bottom Bracket Drop	80mm	80mm	80mm
Bottom Bracket Height	307.2mm	307.2mm	307.2mm
Chainstay Length	451mm	451mm	451mm
Chainstay Length Horizontal	443.9mm	443.9mm	443.9mm
Front-Center	651.1mm	671.9mm	693.3mm
Front-Center Horizontal	646.2mm	667.2mm	688.7mm
Wheelbase	1090mm	1111mm	1132.5mm
Fork Offset/Rake	43mm	43mm	43mm
Fork Length (Axle-To-Crown)	468mm	468mm	468mm
Trail	95.2mm very high	95.2mm very high	95.2mm very high
Mechanical Trail	89.4mm	89.4mm	89.4mm
Wheel Flop	30.6mm	30.6mm	30.6mm
Standover Height	805mm	840mm	875mm
Tire to Pedal Spindle	88.9mm 175 mm cranks	109.7mm 175 mm cranks	131.1mm 175 mm cranks
Pedal Spindle to Ground Clearance	132.2mm 175 mm cranks	132.2mm 175 mm cranks	132.2mm 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