Opus BIG City LRT

Name: Opus BIG City LRT
Brand: Opus

2025 UrbanCommuter Manufacturer page

Suspension: Rigid
Wheels: 650b
Drivetrain: 1 × 9 38t / 11–36t
Gear range: 327%
Weight: 12.47 kg 27.5 lb · Reference configuration not specified
Frame: Aluminum
Brakes: Hydraulic disc

Rider height by size (cm)

Size guide

XS 156–166
SM 163–174
MD 171–182
LG 179–189
XL 185–195

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

Alloy frame and fork Not identified

Suspension

1 part

Fork

Aluminum tapered 1-1/4 to 1-1/8 in Not identified

Drivetrain

7 parts

Brakes

2 parts

Wheels and tires

4 parts

Cockpit and contact points

6 parts

Handlebar

Alloy butted 12 mm rise Not identified
Headset
- FSA ORBIT IS 138
Pedals

FPD NW-247 Not identified

NW-247
Saddle
- Opus
Seatpost
- ProMax
Stem
- ProMax

Sizes and geometry

5 sizes Open in the geometry plotter

Enter your height to highlight matching ranges.

Size MD

Table

Geometry diagram unavailable

The drawing needs wheelbase, which the manufacturer did not publish. Available facts remain in the table.

Size Reported by the manufacturer

Complete manufacturer geometry table 5 published sizes

Complete manufacturer geometry by size
Measurement
Frame
Reachmm	375	385	395	405	415
Stackmm	560	575	590	605	620
Top tube lengthmm	530	550	570	590	610
Seat tube lengthmm	380	420	460	500	540
Head tube lengthmm	148	163	183	198	213
Head tube angle	71°	71.25°	71.5°	71.75°	72°
Seat tube angle	74.5°	74°	73.5°	73°	72.5°
Chainstay lengthmm	440	445	445	445	450
Bottom bracket dropmm	65	65	60	60	60
Standover heightmm	726	752	783	808	834
Stack/reach ratio	1.49	1.49	1.49	1.49	1.49
Suspension and parts
Crank lengthmm	170	170	175	175	175
Handlebar widthmm	580	600	600	620	620
Stem lengthmm	70	80	80	90	100

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

Specifications

Frame and fork

Intended fit: Unisex
Frame material: Aluminum
Fork material: Aluminum
Bicycle weight: 12.47 kg

27.5 lb

Suspension

Suspension configuration: Rigid

Drivetrain

Derived by Bikelake

Front chainrings: 1
Smallest chainring: 38
Largest chainring: 38
Rear sprockets: 9
Smallest sprocket: 11
Largest sprocket: 36
Lowest gear: 29.0 in
Highest gear: 95.0 in

Wheels and brakes

Wheel configuration: Same size
Brake type: Hydraulic disc

Fit and controls

Seatpost: Rigid seatpost
Shifting: Mechanical

Additional specifications

Tire width: 45c
Wheel material: Aluminum
Wheel size: 650b

Gearing

Estimated speeds at 80 rpm

Lowest gear: 11.1 km/h
Highest gear: 36.4 km/h

Total gear range 327%

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: 29.0–95.0 gear inches

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 2025 builds
Specification	This bicycle Opus BIG City LRT	Opus BIG City	Opus BIG City 2
Frame
Fork material	Aluminum	Aluminum	Steel
Bicycle weight	12.47 kg	11.88 kg	12.75 kg
Drivetrain
Front chainrings	1	3	3
Smallest chainring	38	22	24
Largest chainring	38	44	42
Rear sprockets	9	9	8
Largest sprocket	36	28	30
Lowest gear	29.0 in	21.6 in	22.0 in
Highest gear	95.0 in	110.0 in	105.0 in
Brakes
Brake type	Hydraulic disc	Hydraulic disc	Mechanical disc