Top 10 Biggest production bikes

SO, TRIUMPH is reviving the Rocket III after a couple of years’ absence from the European market.

We’ll have to wait until May to discover the new bike’s exact specs, but Triumph is claiming – as it did with the original – that the Rocket will have the world’s biggest production engine for bikes. The old model, introduced in 2004, was developed as 2000cc triple but late in its pre-production was ramped up to 2294cc to grab that title, and there are rumours that the new version will be bigger still.

But how large does it need to be if it’s really going to be the largest-engined production bike? We’ve dug through the archives to find the top 10 contenders for the title.

10: Harley-Davidson 117 Milwaukee-Eight: 1923cc

The 117cu-in Milwaukee Eight engine is fitted to several of Harley’s top models in its current range. All the models in the current ‘CVO’ range – the CVO Road Glide, CVO Street Glide and CVO Limited – use the 1923cc version of the firm’s latest V-twin, making them among the largest Harleys ever built. But despite that, they just squeeze into 10th place on this list and achieve an underwhelming-sounding 105hp.

9: Harley-Davidson 120ST engine: 1962cc

Back in 2015 and 2016, Harley had an even bigger engine in its line-up. The 120ST engine was available as a ‘crate’ engine to bolt into any Twin Cam powered bike, and was certified as an option on several models including the Ultra Classic, Road Glide, Road King and Street Glide. But like one of those body-builders who’s out of breath after a brief jog, it managed a disappointing 91hp.

8: Morgan 3-Wheeler: 1979cc

Yes, you’re right. It’s a car. But legally the Morgan 3-Wheeler is classed as a motorcycle, and it’s got a big engine so we’re having it. Actually, that engine is an S&S V-twin, a motor that’s also used in a host of small-run custom bikes, so it’s fair enough to include it in here. That’s our argument, and we’re sticking to it.

7: Boom Trikes Mustang 2.0 turbo: 1999cc

The Morgan in 7th place is a three-wheeled car with a motorcycle engine. The Boom Trikes Mustang is a three-wheeled motorcycle with car engine. And at 1999cc, it just edges it in terms of capacity. The engine is actually a turbocharged four-cylinder Ford EcoBoost, capable of 200hp and usually found in cars like the Galaxy, Mondeo and various Volvos. Oh, and at 780kg, the Mustang is significantly heavier than the more car-like, 585kg Morgan 3-Wheeler.

6: S&S V124 V-twin (eg Arch Motorcycles KRGT-1): 2032cc

American engine-maker S&S might have started out tuning Harley motors but for years now its V-twin motors have been entirely made in-house. Its 2032cc ‘124’ engine has been approved as emissions-legal to be sold in various small-run bikes over the years, getting it into 6th place. Examples to use the engine include Arch Motorcycles machines. It’s worth mentioning that S&S also makes a much bigger ‘143’ engine – that’s 2343cc – as an upgrade for Harleys or the basis of one-off bikes, but we’re not aware of any production bikes that use it.

Head to page two for the top five >>>