Triumph T120 R Bonneville Specs (Top Speed | Horsepower | Weight)

The Triumph T120 R Bonneville motorcycle specifications include a 649 cc (39.60 cu in) engine, power of 46 hp (33.6 kW) @ 6,700 rpm, a 4-speed gearbox, and a listed weight of 178 kg (392.4 lb).

Key specifications

1960-1962Model years
649 ccDisplacement
46 hpPower
178 kgDry weight
770 mmSeat height
15.1 LFuel tank
1,400 mmWheelbase
127 mmGround clearance
Model years covered
196019611962
Year-specific specification changes

The 1960 model is treated as the standard specification. Only later model years with a different supplied value are shown below.

Power
196246 hp (33.6 kW) @ 6,500 rpm
Electrical
1962Lucas RM19 alternator

How the Triumph T120 R Bonneville compares

This compares the motorcycle with all Triumph models in this specifications database. The blue marker is this model and the grey line is the Triumph database average.

Engine power46 hp
Low 10 hpAverage 87.2 hpHigh 165 hp

About 47% lower than the Triumph database average. Around the 15th percentile across Triumph models.

Displacement649 cc
Low 199 ccAverage 949 ccHigh 2,294 cc

About 32% lower than the Triumph database average. Around the 18th percentile across Triumph models.

Seat height770 mm
Low 690 mmAverage 789 mmHigh 855 mm

Very close to the Triumph database average. Around the 27th percentile across Triumph models.

Fuel capacity15.1 L
Low 9.5 LAverage 17.9 LHigh 25 L

About 15% smaller than the Triumph database average. Around the 22nd percentile across Triumph models.

This model Triumph database average

Triumph database percentile rankings

Percentiles show where this motorcycle sits across the Triumph specifications database. They are descriptive database rankings, not performance ratings.

Engine power15th

46 hp — more powerful than about 15% of Triumph models with power data.

Displacement18th

649 cc — larger displacement than about 18% of Triumph models.

Seat height27th

770 mm — taller than about 27% of Triumph models.

Fuel capacity22nd

15.1 L — larger than about 22% of Triumph fuel tanks in this database.

Dimensions compared with Triumph average

Each measurement is compared with the average value across Triumph models where that dimension is available.

Wheelbase1,400 mm
This bike

1,400

Triumph avg

1,491

6% below average.

Seat height770 mm
This bike

770

Triumph avg

789

Close to average.

Ground clearance127 mm
This bike

127

Triumph avg

124

Close to average.

Mechanical overview

Engine layout snapshot

Twin, four-stroke • 649 cc • Air cooled • 46 hp
Chassis snapshot

Wheelbase 1,400 mmSeat 770 mmClearance 127 mm
4-speed • Chain (final drive) • 3.25-18 front / 4.00-18 rear

Additional useful specifications

Front tire size 3.25-18
Rear tire size 4.00-18
Power-to-weight ratio 0.258 hp/kg
Power-to-weight 258.4 hp/tonne
Specific power 70.9 hp/L
Bore/stroke ratio 0.87:1 (Undersquare)

Engine specifications

Engine type Twin, four-stroke
Displacement 649 cc (39.60 cu in)
Power 46 hp (33.6 kW) @ 6,700 rpm
Bore × stroke 71.0 x 82 mm (2.8 x 3.2 inches)
Cooling system Air
Fuel system Carburettor. Amal monobloc carburettor
Fuel control Overhead Valves (OHV)
Ignition Lucas K2F auto-advance Magneto

Transmission and drivetrain

Gearbox 4-speed
Final drive Chain (final drive)
Clutch Multi-plate, wet

Chassis and suspension

Frame Duplex frame
Front suspension Telescopic fork, hydraulic damping.
Rear suspension Twin shocks. Girlings 100 lb/ft spring tension, adjustable pre-set.

Brakes, wheels and tires

Front brakes Expanding brake (drum brake)
Rear brakes Expanding brake (drum brake)
Front tire 3.25-18
Rear tire 4.00-18

Dimensions and weight

Dry weight 178 kg (392.4 lb)
Seat height 770 mm (30.3 inches)
Wheelbase 1,400 mm (55.1 inches)
Ground clearance 127 mm (5.0 inches)

Fuel and emissions

Fuel capacity 15.14 L (4.00 US gal)

Performance

Top speed 185.0 km/h (115.0 mph)
Power/weight ratio 0.2584 hp/kg

Electrical and instruments

Electrical AC Alternator

Other specifications

Color options Sky Blue/Silver Sheen/Gold Pinstripe
Seat Dual seat

Disclaimer: Specifications may vary by market, trim, production date and optional equipment, and scraped or historical data can contain errors. Comparison and percentile values are calculated from Triumph models in this specifications database. Always double-check important specifications against the motorcycle owner’s/service manual and official Triumph information before relying on them. Visit the official Triumph website.