Opus Fortitude FB Tiagra

Name: Opus Fortitude FB Tiagra
Brand: Opus

2025 RoadEndurance Manufacturer page

Opus Fortitude FB Tiagra, color Crystal Blue

Suspension: Rigid
Wheels: 700c
Drivetrain: 2 × 10 30–46t / 11–32t
Gear range: 446%
Frame: Aluminum
Brakes: Hydraulic disc

Rider height by size (cm)

Size guide

XS 151–164
SM 159–170
MD 165–177
LG 171–184

Components

15 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

Aluminum Not identified

Suspension

1 part

Fork

Carbon Tapered 1-1/4 to 1-1/8 in Not identified

Drivetrain

7 parts

Bottom bracket

BB68 sealed cartridge Not identified
Cassette
- Shimano CS-HG500-10 10 speeds 11–32t
CS-HG500-10
Chain
- KMC X10 10 speeds
Crankset
- Prowheel
RPL-521TT
Front derailleur
- Shimano Tiagra FD-4700 2 speeds
FD-4700
Rear derailleur
- Shimano Tiagra RD-4700 10 speeds
RD-4700
Shifters
- Shimano Tiagra SL-4700 2 speeds
SL-4700

Brakes

2 parts

Wheels and tires

4 parts

Cockpit and contact points

6 parts

Handlebar

Alloy 31.8mm Not identified
Headset

TH Integrated Sealed Not identified
Pedals

None
Saddle
- Opus
Seatpost
- ProMax
Stem
- ProMax

Sizes and geometry

4 sizes Open in the geometry plotter

Enter your height to highlight matching ranges.

Size SM

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 4 published sizes

Complete manufacturer geometry by size
Measurement
Frame
Reachmm	380	389	398	407
Stackmm	539	562	581	598
Top tube lengthmm	530	550	570	590
Seat tube lengthmm	420	460	500	540
Head tube lengthmm	100	125	145	165
Head tube angle	71°	71.5°	72°	72°
Seat tube angle	74.5°	74°	73.5°	73°
Chainstay lengthmm	430	435	435	435
Bottom bracket dropmm	80	78	76	74
Bottom bracket heightmm	256	258	260	262
Stack/reach ratio	1.42	1.45	1.46	1.47
Suspension and parts
Crank lengthmm	165	170	170	172.5
Handlebar widthmm	580	600	600	620
Stem lengthmm	80	80	90	90

Not published by the manufacturer: Wheelbase, Front center, Standover 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: Carbon

Suspension

Suspension configuration: Rigid

Drivetrain

Derived by Bikelake

Front chainrings: 2
Smallest chainring: 30
Largest chainring: 46
Rear sprockets: 10
Smallest sprocket: 11
Largest sprocket: 32
Lowest gear: 27.2 in
Highest gear: 121.3 in

Wheels and brakes

Wheel configuration: Same size
Brake type: Hydraulic disc

Fit and controls

Seatpost: Rigid seatpost
Shifting: Mechanical

Additional specifications

Tire clearance: Maximum tire width: 35c
Tire width: 35c
Wheel material: Aluminum
Wheel size: 700c

Technical analysis

3 measures

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

Lowest gear

27.2 gear inches

This value is below the central range for this class.

Cohort: Road / Endurance Model year: 2025
Sample: 546 bicycles with this information
Coverage: 81.8% of the class

Highest gear

121.3 gear inches

This value is below the central range for this class.

Cohort: Road / Endurance Model year: 2025
Sample: 546 bicycles with this information
Coverage: 81.8% of the class

Shifting

Mechanical

356 of 663 bicycles with this information use electronic shifting.

Cohort: Road / Endurance Model year: 2025
Sample: 663 bicycles with this information
Coverage: 99.4% of the class

Gearing

Estimated speeds at 80 rpm

Lowest gear: 10.4 km/h
Highest gear: 46.4 km/h

Total gear range 446%

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: 27.2–121.3 gear inches
Class reference (p10–p90): 26.6–139.2 gear inches; The band runs from p10 for the lowest gear to p90 for the highest gear.

Cohort: Road / Endurance Model year: 2025
Lowest gear: 546 bicycles with this information, 81.8% of the class
Highest gear: 546 bicycles with this information, 81.8% 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 2025 builds

Differences across 2025 builds
Specification	This bicycle Opus Fortitude FB Tiagra	Opus Fortitude 105	Opus Fortitude Claris	Opus Fortitude Tiagra
Frame
Fork material	Carbon	Carbon	Aluminum	Carbon
Bicycle weight	Not informed	9.4 kg	9.7 kg	9.5 kg
Drivetrain
Smallest chainring	30	34	32	34
Largest chainring	46	50	48	50
Rear sprockets	10	12	8	10
Largest sprocket	32	34	32	34
Lowest gear	27.2 in	29.0 in	29.0 in	29.0 in
Highest gear	121.3 in	131.8 in	126.6 in	131.8 in
Brakes
Brake type	Hydraulic disc	Hydraulic disc	Rim brake	Hydraulic disc
Other specifications
Tire clearance	Maximum tire width: 35c	Maximum tire width: 35c	Not informed	Maximum tire width: 35c
Tire width	35c	32c	28c	32c