Surly Midnight Special 650b

Name: Surly Midnight Special 650b
Brand: Surly

2026 RoadGravel Manufacturer page

Last known price: $2,349

Prices shown first for United States
Suspension: Rigid
Wheels: 650b
Drivetrain: 1 × 11 40t / 11–42t
Gear range: 382%
Frame: Steel
Brakes: Mechanical disc

Sizes

Size guide

40cm
46cm
50cm
54cm
56cm
58cm
60cm
64cm

The manufacturer did not publish rider heights for these sizes.

Components

16 of 20 identified

Parts found in a manufacturer catalog show their brand, model and key numbers, and the steps show how precisely they are identified: brand, series, model, or the exact product. The info button has every detail and the text the manufacturer published.

Frame and fork

1 part

Frame

Surly Midnight Special 4130 Chromoly, Natch tubing, double-butted main triangle, TIG welded, ED coated Not identified

Suspension

1 part

Fork
- Surly

Drivetrain

7 parts

Bottom bracket

68mm threaded (1.37" x 24TPI) Not identified
Cassette
- SunRace 11–42t
Chain
- KMC X11 11 speeds
Crankset
- SRAM Rival 1 10 speeds 40t
Front derailleur

None
Rear derailleur
- SRAM Rival 1 11 speeds
Shifters
- SRAM Rival

Brakes

3 parts

Brake levers
- SRAM Rival 1 Brake
Brakes
- TRP Spyre
Disc rotors

Flat-mount 140 (160mm max rotor), 25mm thick mount Not identified

Wheels and tires

4 parts

Cockpit and contact points

5 parts

Sizes and geometry

8 sizes Open in the geometry plotter

Complete rider-height ranges are not published for these sizes. You can still explore the geometry below.

Size 54cm

Table

Reach 389mm

Stack 560mm

Wheelbase 1018mm

Head angle 72.5°

Seat angle 73.5°

Every size is drawn to the same scale, in millimeters. Explanatory schematic on an assumed 650b wheel; exact published values are in the table below.

Size Reach Stack

Complete manufacturer geometry table 8 published sizes

Complete manufacturer geometry by size
Measurement
Frame
Reachmm	363	366	379	389	393	402	409	423
Stackmm	531	538	544	560	580	599	620	641
Top tube lengthmm	500	520	540	555	570	585	605	625
Seat tube lengthmm	400	460	500	540	560	580	600	640
Head tube lengthmm	95	100	110	125	140	160	180	200
Head tube angle	71°	71.5°	72°	72.5°	73°	73°	73.5°	74°
Seat tube angle	75.5°	74°	73.5°	73.5°	73°	73°	72.5°	72.5°
Chainstay lengthmm	425	425	425	425	425	425	425	425
Wheelbasemm	993	994	1007	1018	1012	1027	1036	1050
Front centermm	578	579	591	602	596	610	619	633
Bottom bracket dropmm	70	70	65	65	65	65	65	65
Standover heightmm	720	751	778	806	827	846	866	895
Fork rakemm	50	50	50	50	40	40	40	40
Trailmm	62	58	55	52	59	59	55	53
Stack/reach ratio	1.46	1.47	1.44	1.44	1.48	1.49	1.52	1.52
Suspension and parts
Crank lengthmm	165	170	170	175	175	175	175	175
Handlebar widthmm	400	400	400	420	440	440	460	460
Stem lengthmm	70	80	80	100	100	120	120	120

Not published by the manufacturer: Bottom bracket height, Front travel, Rear travel, Stem angle, Seatpost length and Dropper post travel.

Specifications

Frame and fork

Intended fit: Unisex
Frame material: Steel
Fork material: Steel

Suspension

Suspension configuration: Rigid

Drivetrain

Derived by Bikelake

Front chainrings: 1
Smallest chainring: 40
Largest chainring: 40
Rear sprockets: 11
Smallest sprocket: 11
Largest sprocket: 42
Lowest gear: 26.2 in
Highest gear: 100.0 in

Wheels and brakes

Wheel configuration: Same size
Brake type: Mechanical disc

Fit and controls

Seatpost: Rigid seatpost
Shifting: Mechanical

Additional specifications

Bottom bracket standard: BSA
Tire width: 47c
Wheel material: Aluminum
Wheel size: 650b

Technical analysis

3 measures

How these figures sit among bicycles of the same class and model year. Context, not a ranking.

Lowest gear

26.2 gear inches

This value is within the central range for this class.

Cohort: Road / Gravel Model year: 2026
Sample: 1,455 bicycles with this information
Coverage: 73.2% of the class

Highest gear

100.0 gear inches

This value is below the central range for this class.

Cohort: Road / Gravel Model year: 2026
Sample: 1,455 bicycles with this information
Coverage: 73.2% of the class

Shifting

Mechanical

706 of 1,980 bicycles with this information use electronic shifting.

Cohort: Road / Gravel Model year: 2026
Sample: 1,980 bicycles with this information
Coverage: 99.6% of the class

Gearing

Estimated speeds at 80 rpm

Lowest gear: 10.0 km/h
Highest gear: 38.3 km/h

Total gear range 382%

Technical details and class reference

These speeds describe the gearing at the selected cadence, not how fast you can ride.
Calculated from published gear-inch values and their wheel-size assumptions.
These gearing values describe the bicycle, not a selected frame size.
A 100% range means one ratio; 500% means the highest ratio is five times the lowest.
For e-bikes, motor assistance cutoff is not represented.

Gear-inch range

Lower gear-inch values travel less distance per pedal revolution; higher values travel farther.

This bicycle: 26.2–100.0 gear inches
Class reference (p10–p90): 22.8–127.6 gear inches; The band runs from p10 for the lowest gear to p90 for the highest gear.

Cohort: Road / Gravel Model year: 2026
Lowest gear: 1455 bicycles with this information, 73.2% of the class
Highest gear: 1455 bicycles with this information, 73.2% of the class

Lineup changes

The published facts that differ across this family's builds and from the same model a year earlier. Missing information never counts as zero.

Differences across 2026 builds
Specification	This bicycle Surly Midnight Special 650b	Surly Midnight Special 700c
Frame
Fork material	Steel	Carbon
Drivetrain
Front chainrings	1	2
Smallest chainring	40	34
Largest chainring	40	50
Rear sprockets	11	12
Largest sprocket	42	34
Lowest gear	26.2 in	29.0 in
Highest gear	100.0 in	131.8 in
Brakes
Brake type	Mechanical disc	Hydraulic disc
Other specifications
Tire width	47c	35c
Wheel material	Aluminum	Carbon
Wheel size	650b	700c