Principia RD2

Name: Principia RD2
Brand: Principia

2024 RoadGeneral road Manufacturer page

Price: Not published

Prices shown first for United States
Europe: €3,999 Last known price
Suspension: Rigid
Wheels: 700c
Drivetrain: 2 × 12 34–50t / 10–51t
Gear range: 750%
Weight: 8.5 kg 18.7 lb · Reference configuration not specified
Frame: Carbon
Brakes: Hydraulic disc

Sizes

Size guide

45cm
48cm
51cm
54cm
57cm
60cm

The manufacturer did not publish rider heights for these sizes.

Components

13 of 16 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

Full monocoque carbon Not identified

Suspension

1 part

Fork

Full monocoque carbon Not identified

Drivetrain

5 parts

Bottom bracket
- Shimano SM-BB72
SM-BB72
Cassette
- Shimano Deore XT CS-M8100 12 speeds 10–51t
CS-M8100
Crankset
- Shimano Ultegra FC-R8100 50/34t
FC-R8100
Front derailleur
- Shimano Ultegra FD-R8150 2 speeds
FD-R8150
Rear derailleur
- Shimano Ultegra RD-R8150 12 speeds
RD-R8150

Brakes

1 part

Brakes
- Shimano Ultegra BR-R8170
BR-R8170

Wheels and tires

2 parts

Cockpit and contact points

6 parts

Sizes and geometry

6 sizes Open in the geometry plotter

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

Size 51cm

Table

Reach 385mm

Stack 522mm

Wheelbase 977mm

Head angle 72.5°

Seat angle 73.5°

Every size is drawn to the same scale, in millimeters. Explanatory schematic on an assumed 700c wheel; exact published values are in the table below.

Size Reach Stack

Complete manufacturer geometry table 6 published sizes

Complete manufacturer geometry by size
Measurement
Reachmm	380.8	386.1	385.3	384.9	388.1	404.3
Stackmm	500.8	500.8	522.1	557.2	578.6	607.3
Top tube lengthmm	515	525	540	550	565	590
Seat tube lengthmm	450	480	510	540	570	600
Head tube lengthmm	95	95	120	155	180	210
Head tube angle	72.5°	72.5°	72.5°	73°	73°	73°
Seat tube angle	75°	74.5°	73.5°	73.5°	73°	73°
Chainstay lengthmm	408	408	408	408	410	410
Wheelbasemm	964.6	969.8	976.9	982.9	995.9	1020.9
Front centermm	568	573	579	585	595	620
Bottom bracket dropmm	72.5	72.5	70	70	67.5	67.5
Bottom bracket heightmm	270.5	270.5	273	273	275.5	275.5
Standover heightmm	698.8	718.7	744.4	774.8	802.3	830.4
Fork rakemm	45	45	45	45	45	45
Trailmm	59.3	59.3	59.3	56.4	56.4	56.4
Stack/reach ratio	1.32	1.30	1.36	1.45	1.49	1.50

Not published by the manufacturer: Front travel, Rear travel, Crank length, Handlebar width, Stem length, Stem angle, Seatpost length and Dropper post travel.

Specifications

Frame and fork

Intended fit: Unisex
Frame material: Carbon
Fork material: Carbon
Bicycle weight: 8.5 kg

18.7 lb

Suspension

Suspension configuration: Rigid

Drivetrain

Derived by Bikelake

Front chainrings: 2
Smallest chainring: 34
Largest chainring: 50
Rear sprockets: 12
Smallest sprocket: 10
Largest sprocket: 51
Lowest gear: 19.3 in
Highest gear: 145.0 in

Wheels and brakes

Wheel configuration: Same size
Brake type: Hydraulic disc

Fit and controls

Seatpost: Rigid seatpost
Shifting: Electronic

Additional specifications

Bottom bracket standard: BB86/BB92
Tire width: 28c
Wheel material: Aluminum
Wheel size: 700c

Technical analysis

1 measure

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

Shifting

Electronic

7 of 72 bicycles with this information use electronic shifting.

Cohort: Road / General road Model year: 2024
Sample: 72 bicycles with this information
Coverage: 100.0% of the class

Gearing

Estimated speeds at 80 rpm

Lowest gear: 7.4 km/h
Highest gear: 55.5 km/h

Total gear range 750%

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: 19.3–145.0 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.

Changes since 2023

Changes since 2023
Specification	2023 Principia RD2	This bicycle Principia RD2
Drivetrain
Smallest chainring	Not informed	34
Largest chainring	Not informed	50
Smallest sprocket	Not informed	10
Largest sprocket	Not informed	51
Lowest gear	Not informed	19.3 in
Highest gear	Not informed	145.0 in