The Triumph Rocket III initially began as a project back in 1998. At that time, Triumph was trying to find a way to break into the American big cruiser market that was dominated by Harley-Davidson. After years of development, the Rocket III was launched in 2004, signifying a move by Triumph to become a major player in a segment that featured big bikes with big engines.

Well, it doesn’t get any bigger than the Rocket III, thanks in large part to having a 2.3-liter, three-cylinder engine lying inside of it. In case you didn’t know, that’s the biggest engine of any production motorcycle in the business today.

Despite initially struggling to find its own niche, the Rocket III eventually settled in as a street fighter with the Rocket III Roadster eventually becoming the most powerful bike in the entire lineup.

For what it’s worth, the Rocket III will continue to hold this title until a bigger bike comes into the scene. That’s a future that likely won’t arrive anytime soon.

Click past the jump to read more about the Triumph Rocket III Roadster.

  • 2015 Triumph Rocket III Roadster
  • Year:
  • Make:
  • Engine:
    Liquid-cooled, DOHC, in-line 3-cylinder
  • Transmission:
  • Horsepower @ RPM:
  • Torque @ RPM:
  • Energy:
    Multipoint sequential electronic fuel injection
  • Displacement:
    2294 cc
  • Price:


2015 Triumph Rocket III Roadster Exterior
- image 615960

There are a lot of superlatives you can throw in the direction of the Triumph Rocket III without having to go overboard with all the hyperbole. That said, you only need to look at this beefy ride to understand that this bike is for men who can handle. No boys allowed here! Everything about the Rocket III design can be described as “oversized.”

That includes the chrome-finished front engine dresser bars that matches really well with the highway pegs to ensure a comfortable seating position for the rider. Oh, and that plush leather seat? Really comfortable, too! I especially like way it curves up at the end to give some kind of comfort to the lower back. A lot of bikes have this, but not to the level of comfort that the Rocket III has.

Notice also how the Rocket III has twin headlamps that sit side-by-side from each other? That’s a trademark of the Rocket III. Same with the prevalent amount of chrome details throughout the bike that’s offset by blackened components, specifically the radiator cowls, the rear mudguard rails, the airbox cover, fork protectors, and mirrors. All these details were carefully added to give the Rocket III a menacing appearance, not that it needed to because it’s already pretty intimidating to look at on its own.

Design Specifications

Length 2500 mm
Width handlebars 970 mm
Height without mirror 1165 mm
Seat height 750 mm
Wheelbase 1695mm
Rake 32˚
Trail 148mm
Tank capacity 24l
Wet weight 367 kg
Dry weight 334 kg


2015 Triumph Rocket III Roadster High Resolution Exterior
- image 615951

Befitting of a bike that features the biggest engine in the motorcycle world, Triumph made sure that the Rocket III had the frame that was up to task. The company did just that by using a big, tubular steel twin spine frame that’s strong and rigid enough to handle that massive engine. Remember, 2.3 liters may be small in the world of cars, but it’s a mammoth motor in the motorcycle world. The twin spin spine frame is there to ensure that the engine can sit comfortably without compromising the bike’s performance characteristics.

Similarly, Triumph also gave the Rocket III’s front end with d sports-bike-style upside down forks measuring 1.7 inches in diameter. The suspension allows the Rocket III to have the sturdiness to handle the road force the bike will undoubtedly be subjected to.

A bike with the size of the Rocket III also needs a wheel-and-tire setup that can handle all of its quirks, for better or for worse. As such, Triumph fitted a 16-inch rear wheel to emphasize the bike’s size while also allowing it the agility and versatility to handle whatever road condition it finds itself in. The last piece of the puzzle are the brakes and in this instance, the Rocket III was given a pair of vice-like, four-piston callipers that grips the front and rear discs and backed up by the company’s own ABS system.

Frame Specifications

Frame Tubular steel, twin spine
Swingarm Twin-sided, steel (houses drive shaft)
Front Wheels Cast aluminium alloy 5 spoke, 17 x 3.5in
Rear Wheels Cast aluminium alloy 5 spoke, 16 x 7.5in
Front Tyres 150/80 R17
Rear Tyres 240/50 R16
Front Suspension Kayaba 43mm upside down forks, 120mm travel
Rear Suspension Kayaba black spring twin shocks with 5 position adjustable preload, 105mm rear wheel travel
Brakes front Twin 320mm floating discs, Nissin 4-piston fixed calipers, ABS
Brakes rear Single 316mm disc, Brembo 2-piston floating caliper, ABS


2015 Triumph Rocket III Roadster Exterior
- image 615954

I’ve probably beaten this feature a lot by now, but it’s still worth repeating. The Triumph Rocket III Roadster has the biggest engine of any production motorcycle in the world. Try looking for another motorcycle that has a 2,294 cc liquid-cooled, three-cylinder engine and you’re likely going to have no luck doing so. The massive motor on the Rocket III certainly allows it to live up to its name, thanks in large part to output numbers that hit 148 horsepower at 5,750 rpm and 163 pound-feet of torque at 2,750 rpm.

It’s not the fastest bike in the world but that’s not the point. What you get is unbridled power that can still hit a standing quarter-mile in just 12.2 seconds to go with a top speed of 137 mph.

Drivetrain Specifications

Engine type Liquid-cooled, DOHC, in-line 3-cylinder
Capacity 2294cc
Bore 101.6mm
Stroke 94.3mm
Fuel system Multipoint sequential electronic fuel injection with twin butterflies and progressive linkage on primary butterflies
Exhaust Stainless steel 3 into 1 into 2, large volume catalysts in front of chrome-plated silencers
Final drive Shaft
Clutch Wet, multi-plate
Gearbox 5-speed
Oil capacity 5.9L
Max power ec 148BHP @ 5750
Max torque ec 221NM @ 2750
Color Options Matt Phantom Black, Phantom Black


2015 Triumph Rocket III Roadster High Resolution Exterior
- image 615953

The Triumph Rocket III is priced at $15,499. The company also provides customers with a two-year unlimited mileage warranty on Triumph and Genuine Accessories to go with a 12-month unlimited mileage warranty on replacement parts and 10,000-mile service intervals.


2015 Triumph Rocket III Roadster High Resolution Exterior
- image 615956

“The Rocket III Roadster is a totally unique kind of motorcycle with the most unmistakable presence on two wheels. A true one-off it defies convention and category. But one ride tells you that they are about surprising levels of agility and performance in a bike that can deliver an engaging ride every day. They just happen to do it with that pure classic cruiser style.” ----- Total Motorcycle

“2.3 litres. 221Nm of torque. Blacked out. Blinged up. Streetfighting cruiser. Hard. The Rocket III Roadster is not normal, it is very, very special. No other motorcycle on the planet comes close to delivering the tree-pulling levels of torque that comes as standard with the turbine-like triple. Twist and go. Sounds great, stops great. Standard ABS. Classic streetfighter looks.” ----- Autobase

Kirby Garlitos
Automotive Aftermarket Expert -
Kirby’s first exposure into the world of automobiles happened when he caught Knight Rider on television as a five-year old boy. David Hasselhoff didn’t leave much of an impression on him (that happened later on in Baywatch), but KITT certainly did. To this day, Kirby remains convinced that he will one day own a car with the same ‘spirit’ as the original KITT (not the 2008 monstrosity). He doesn't know when that will be, but until then, he’s committed to expressing his love for KITT, and all cars for that matter, here at TopSpeed.  Read More
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