Centurion Backfire Fit E R811i Dual Batt EQ

2025 MountainCross-country Electric bicycle Manufacturer page

Fork travel: 100 mm
Wheels: 27.5″, 29″
Drivetrain: 1 × 12 34t / 11–50t
Gear range: 455%
Battery: 625 Wh
Weight: 26.4 kg 58.2 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

27 of 28 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

Backfire Fit R intube, Material: Aluminium, Steuerrohr: 1.5" straight, Ausfallende: 12x148 mm, Bremsaufnahme: Postmount 180 mm, Rahmenkennung: TBP032A Not identified

Electric system

4 parts

Suspension

1 part

Fork
- SR Suntour

Drivetrain

6 parts

Brakes

2 parts

Wheels and tires

5 parts

Cockpit and contact points

5 parts

Other components

4 parts

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 reach and stack, 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
Top tube lengthmm	555	581	607	633	659
Seat tube lengthmm	380	430	480	530	580
Head tube lengthmm	130	110	130	150	170
Head tube angle	68.5°	69.75°	70°	70.25°	70.5°
Seat tube angle	73.5°	73.5°	73.5°	73.5°	73.5°
Chainstay lengthmm	445	460	460	460	460
Wheelbasemm	1086	1105	1129	1153	1177
Front centermm	646	654	677	701	725
Bottom bracket dropmm	50	68	68	68	68
Bottom bracket heightmm	305	306	306	306	306
Standover heightmm	726	756	782	809	840

Not published by the manufacturer: Reach, Stack, Fork rake, Trail, Stack/reach ratio, 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: Aluminum
Bicycle weight: 26.4 kg

58.2 lb
Weight limit: 150 kg

330.7 lb

Suspension

Suspension configuration: Hardtail
Front travel: 100 mm

Drivetrain

Derived by Bikelake

Front chainrings: 1
Smallest chainring: 34
Largest chainring: 34
Rear sprockets: 12
Smallest sprocket: 11
Largest sprocket: 50
Lowest gear: 19.7 in
Highest gear: 89.6 in

Wheels and brakes

Wheel configuration: Same size
Brake type: Hydraulic disc

Fit and controls

Seatpost: Rigid seatpost
Shifting: Mechanical

Electric system

Battery capacity: 625 Wh

Additional specifications

Battery: Bosch PowerTube 625 Wh, DB: Bosch PowerPack 500 Wh
Fork spring: Air
Tire width: 2.25″
Wheel material: Aluminum
Wheel size: 27.5″, 29″

Technical analysis

2 measures

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

Front travel

100 mm

This value is within the central range for this class.

Cohort: Mountain / Cross-country Model year: 2025
Sample: 1,507 bicycles with this information
Coverage: 87.8% of the class

Shifting

Mechanical

222 of 1,647 bicycles with this information use electronic shifting.

Cohort: Mountain / Cross-country Model year: 2025
Sample: 1,647 bicycles with this information
Coverage: 95.9% of the class

Gearing

Estimated speeds at 80 rpm

Lowest gear: 7.6 km/h
Highest gear: 34.3 km/h

Total gear range 455%

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: 19.7–89.6 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 Centurion Backfire Fit E R811i Dual Batt EQ	Centurion Backfire E R860i	Centurion Backfire E R860i EQ	Centurion Backfire Fit E R750i	Centurion Backfire Fit E R750i EQ	Centurion Backfire Fit E R760i
Frame
Bicycle weight	26.4 kg	22.5 kg	24 kg	21.6 kg	23.1 kg	22.2 kg
Drivetrain
Smallest chainring	34	34	34	36	36	36
Largest chainring	34	34	34	36	36	36
Rear sprockets	12	12	12	10	10	10
Largest sprocket	50	50	50	42	42	42
Lowest gear	19.7 in	19.7 in	19.7 in	24.9 in	24.9 in	24.9 in
Highest gear	89.6 in	89.6 in	89.6 in	94.9 in	94.9 in	94.9 in
Electric bicycle systems
Battery capacity	625 Wh	625 Wh	625 Wh	500 Wh	500 Wh	625 Wh
Other specifications
Tire width	2.25″	2.4″	2.4″	2.25″	2.25″	2.25″
Wheel size	27.5″ / 29″	29″	29″	27.5″ / 29″	27.5″ / 29″	29″