2021 Surly Bikes Midnight Special Base with Enve Gravel Disc Fork

Design
Drop Bar, Rigid, non-suspension corrected
Frame
Steel
Fork
Steel
Features
Disc brake
Average stack and reachvs category
Average stack and reachvs category
Somewhat aggressive stack and reachvs category
Somewhat aggressive stack and reachvs category
Somewhat aggressive stack and reachvs category
Somewhat aggressive stack and reachvs category
Somewhat aggressive stack and reachvs category
Somewhat aggressive stack and reachvs category

Geometry

40cm
46cm
50cm
54cm
56cm
58cm
60cm
64cm
Stack
531mm
538mm
544mm
560mm
580mm
599mm
620mm
641mm
Reach
363mm
366mm
379mm
389mm
393mm
402mm
409mm
423mm
Stack to Reach Ratio
1.46:1
1.47:1
1.44:1
1.44:1
1.48:1
1.49:1
1.52:1
1.52:1
Seat Tube Length, C-TTT
400mm
460mm
500mm
540mm
560mm
580mm
600mm
640mm
Top Tube Length, Effective/Horizontal HT Top
500mm
520mm
540mm
555mm
570mm
585mm
605mm
625mm
Top Tube Length, Actual C-C
487mm
506mm
531mm
552mm
564mm
579mm
597mm
622mm
Top Tube Slope
14.9deg
8.7deg
4.9deg
2.4deg
2.6deg
2.5deg
2.8deg
1.1deg
Head Tube Angle
71deg
71.5deg
72deg
72.5deg
73deg
73deg
73.5deg
74deg
Seat Tube Angle
75.5deg
74deg
73.5deg
73.5deg
73deg
73deg
72.5deg
72.5deg
Head Tube Length
95mm
100mm
110mm
125mm
140mm
160mm
180mm
200mm
Bottom Bracket Drop
70mm
70mm
65mm
65mm
65mm
65mm
65mm
65mm
Bottom Bracket Height
269mm
269mm
274mm
274mm
274mm
274mm
274mm
274mm
Chainstay Length
425mm
425mm
425mm
425mm
425mm
425mm
425mm
425mm
Chainstay Length Horizontal
419.2mm
419.2mm
420mm
420mm
420mm
420mm
420mm
420mm
Front-Center
578.1mm
579.1mm
590.6mm
601.5mm
595.6mm
610.5mm
619.4mm
633.3mm
Front-Center Horizontal
573.8mm
574.8mm
587mm
598mm
592mm
607mm
616mm
630mm
Wheelbase
993mm
994mm
1007mm
1018mm
1012mm
1027mm
1036mm
1050mm
Fork Offset/Rake
47mm
47mm
47mm
47mm
47mm
47mm
47mm
47mm
Fork Length (Axle-To-Crown)
395mm
395mm
395mm
395mm
395mm
395mm
395mm
395mm
Trail
67mm
high
63.9mm
mid/​neutral
60.7mm
mid/​neutral
57.6mm
mid/​neutral
54.5mm
mid/​neutral
54.5mm
mid/​neutral
51.4mm
mid/​neutral
48.3mm
mid/​neutral
Mechanical Trail
63.4mm
60.6mm
57.8mm
54.9mm
52.1mm
52.1mm
49.3mm
46.4mm
Wheel Flop
20.6mm
19.2mm
17.9mm
16.5mm
15.2mm
15.2mm
14mm
12.8mm
Standover Height
720mm
751mm
778mm
806mm
827mm
846mm
866mm
895mm
Tire to Pedal Spindle
74.1mm
165 mm cranks
70.1mm
170 mm cranks
81.6mm
170 mm cranks
87.5mm
175 mm cranks
81.6mm
175 mm cranks
96.5mm
175 mm cranks
105.4mm
175 mm cranks
119.3mm
175 mm cranks
Pedal Spindle to Ground Clearance
104mm
165 mm cranks
99mm
170 mm cranks
104mm
170 mm cranks
99mm
175 mm cranks
99mm
175 mm cranks
99mm
175 mm cranks
99mm
175 mm cranks
99mm
175 mm cranks

Base with Enve Gravel Disc Fork Build

40cm
46cm
50cm
54cm
56cm
58cm
60cm
64cm
Wheel Size
650B/27.5 in
584 mm BSD
650B/27.5 in
584 mm BSD
650B/27.5 in
584 mm BSD
650B/27.5 in
584 mm BSD
650B/27.5 in
584 mm BSD
650B/27.5 in
584 mm BSD
650B/27.5 in
584 mm BSD
650B/27.5 in
584 mm BSD
Tire Width
47mm
47mm
47mm
47mm
47mm
47mm
47mm
47mm
Tire Width Max
2.35in
2.35in
2.35in
2.35in
2.35in
2.35in
2.35in
2.35in
Tire Outer Diameter
678mm
678mm
678mm
678mm
678mm
678mm
678mm
678mm
Bike Length with Tires
1671mm
1672mm
1685mm
1696mm
1690mm
1705mm
1714mm
1728mm
Crank Length
165mm
170mm
170mm
175mm
175mm
175mm
175mm
175mm
Handlebar Width
400mm
400mm
400mm
420mm
440mm
440mm
460mm
460mm
Stem Length
70mm
80mm
80mm
100mm
100mm
120mm
120mm
120mm
Stem Angle
6deg
6deg
6deg
6deg
6deg
6deg
6deg
6deg

Stack and Reach vs. Category Trend

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.

Learn more about the Upright/Aggressive Scale
Category Trend
All-road/Gravel
Source:https://surlybikes.com/bikes/midnight_special