Honda built a 250cc 6-cylinder race bike that screams so loud at 18,000 rpm it has people cringing and covering their ears
Published on Oct 03, 2026 at 8:05 AM (UTC-4)
by Ben Thompson
Last updated on Oct 03, 2026 at 8:05 AM (UTC-4)
Edited by
Mason Jones
When Honda built the RC166, they had a race bike on their hands that was so loud it had people covering their ears.
Developed to compete in the 250cc class of World Grand Prix motorcycles, the RC166 remains famous for its ferocious roar.
At 18,000 rpm, it’s no wonder this race bike made as much noise as it did.
But beyond making a lot of noise, what was it that set the RC166 apart?
The RC166 was one of many legendary racing machines
While cars get their deserved kudos, motorbikes are often overlooked.
Not that anyone has forgotten how cool they are – that is pretty self-evident.
But their sheer power is often underestimated.
Race bikes have risen to the occasion on different occasions, whether that’s racing against a Tesla Model S Plaid or taking on a Lamborghini Revuelto.
But it’s not just in performance on the track that these bikes are impressing.
The RC166 sounded as fierce as it looked
The RC166 was built back in the 1960s, when Honda was desperately trying to produce 250cc race bikes that could compete against its rivals.
Because four-stroke engines traditionally produced power on every second revolution, Honda needed to spin the engine at extraordinarily high RPMs to stay competitive.
To achieve this without destroying valvetrains or pistons, one engineer divided the 250cc into six tiny cylinders.
The construction of this bike was so precise, it was as intricate as a watch.
But here’s what really set this bike apart – its almighty roar.
In the above clip, you can get a taste of just how loud this engine gets.
The gathered crowd can’t help but wince and cover their ears.
While it was likely a pretty unpleasant experience for their ears, we’re sure they appreciated how cool it was nonetheless.
How did this Honda race bike do in competitive races?
Leaving aside the noise, how did the RC166 fare when it came to the races?
Very well, it turns out.
Ridden by legendary racer Mike ‘The Bike’ Hailwood, the RC166 stormed to victory in all 10 races in the 1966 Grand Prix season.
The following year, it secured five more victories.
Could these be the most iconic motorbikes ever?
Honda Super Cub (1958–present): The most produced motor vehicle in history (over 100 million sold). It revolutionized personal transportation globally with its reliable design, automatic clutch, and accessible price.
Honda CB750 (1969): Widely regarded as the world’s first true ‘superbike’. Introduced an inline-four-cylinder engine, electric start, and a front disc brake to the mass market.
Triumph Bonneville T120 (1959): The quintessential British parallel-twin motorcycle. Became a cultural symbol of 1960s rock ‘n’ roll culture.
BMW R80 G/S (1980): Created the modern Adventure Touring (ADV) segment. Combined long-travel suspension and shaft drive with BMW’s signature boxer-twin engine.
Ducati 916 (1994): Designed by Massimo Tamburini, this machine set the visual benchmark for modern sportbikes with its under-seat exhausts, single-sided swingarm, and aggressive styling.
Ben joined Supercar Blondie in February 2025 after being published by international organizations including LADbible, The Sun, the New York Post, and the Daily Mail. He covers supercars, rare and collectible vehicles, aviation, luxury assets, and the fascinating people behind them. His reporting has explored everything from seven-figure supercars and historic Ferrari collections to unusual aircraft adventures and extraordinary automotive discoveries from around the world. Ben has also gained first-hand insight into vehicle craftsmanship and customization, including visiting specialist workshops to see bespoke vehicles up close.
