I used to own a Honda RC51 that made the most wonderful noise. It sounded like Godzilla stepped on a Lego. I loved the sound of that bike, though I’m sure the neighbors that lived above my parking space did not. I wouldn’t call it the best sounding motorcycle, but it’s up there with the Yamaha R1 and its crossplane crankshaft and pretty much every Ducati.
If we’re looking for the best motorcycle sound though, that comes from the Honda CBX. I was reminded of this recently when a trio of Honda CBX motorcycles pulled into The Rock Store. I waited around for them to leave so I could hear all three of them together, and it was so worth it. I won’t be upset if you get derailed from reading this by getting sucked into a YouTube trap of CBX exhaust sounds. I’ll get you started.
The CBX has a unique and amazing sound thanks to its inline-six-cylinder engine. It wasn’t the first inline-six production motorcycle, that was the Benelli Sei 750. The Benelli Sei was designed by Alejandro de Tomaso, founder of the carmaker De Tomaso. The Sei engine was essentially a Honda CB500 with two extra cylinders. The alternator was moved from the side of the engine to the rear of the cylinders to reduce overall width. Later, Benelli increased the bore and stroke to make a 900 Sei.
Honda did have an inline 6 motorcycle that preceded the Benelli, but it wasn’t a production engine. The Honda RC174 was a Grand Prix racing motorcycle competing in the 350cc class in 1967. The engine was six 49.5cc cylinders each with its own carburetor and exhaust all stacked together in the most adorable engine package. The bike won seven of the eight races that year.
Honda’s first production inline-six came in 1978 when it started selling the CBX, which was briefly the fastest production motorcycle in the world. The engine was a 1,047cc six with 24 valves, six carburetors, and 105 horsepower. Like the Benelli, the alternator was stacked above the transmission instead of being stuck on the sides of the crankshaft as you would typically see. This allowed the engine to be only two inches wider than a CB750. Despite the excellent performance, sales were not great and the motorcycle ended production in 1982.
There have been a few other inline-six motorcycles, like the Kawasaki Z1300 which sold from 1979 to 1989, and the BMW K1600 which has been on sale since 2011. I’m sure those bikes sound great, too, but I’ve never seen three of them pull away from a cafe while a few dozen motorcyclists all stop what they’re doing to watch them symphonically ride off into the hills. So I’m going to give this one to the CBX.