Are V-Twin engines obsolete? Maybe.
With so many available engine configurations, CADD, and advances in metallurgy and machining techniques, why are V-twin engines still in motorcycles? Aren’t there a pile of better configurations, and why haven’t they replaced that V-twin?
They Are Still Popular:
Oh, readers, there is so much to say here. I’ll start with “better is subjective” and go from there. This is why Baskin Robbins makes 31 flavors!
There are so very many engine configuration options when it comes to motorcycles. Singles, parallel twins, V-twins, opposed twins, triples, inline fours, V-fours, (RIP Square Four), flat fours, inline sixes, flat sixes… did I forget any? At any rate, the V-twin is just one of many, and each one has their advantages and disadvantages; admittedly, some more than others. The most popular in the United States is, by far, the V-twin, and I’m going to posit that this is not because of their performance, but because of great marketing: Americans have come to associate the noise of a big V-twin with “freedom” and “America.”
I’m going to make a big assumption here (I know) and figure that this question comes from a rider who doesn’t ride V-twins, loves other configurations, and is perplexed by the entire V-twin cruiser/tourer/bagger aesthetic. But, did you know loads of motorcycles have V-twins?
You might compare numbers for various engines: the peak horsepower they produce along with peak torque, when each happens, and the power to weight ratio. You might compare the gas mileage and the curb weight and the range of each bike. But in reality, the only thing that matters is how riding that bike makes you feel.
I’m sure you’ve run into that “numbers” rider, who will smugly point out that a stock Harley-Davidson 103ci V-twin motor puts out around 65hp at the rear wheel on a dyno, and what good is that, even? Well, it also puts out around 85 ft-lb of torque, and that is what gets any big, heavy bike off a line. You can get deep into the weeds researching frictional losses, intake velocities, and peak piston acceleration, but I will tell you this: unless you’re a mechanical engineer who designs motorcycle engines for a living, you are boring the hell out of the other people on that online forum where you’re showing off your Google University certificate.
I like twins. I currently own three: a parallel twin, an opposed twin and a V-twin, and I will tell you that while they all may be twins, the character of the motor in each of these bikes is quite different. My V-twin is a Suzuki SV650, and the horsepower-to-torque tune of that little motor combined with its light and nimble chassis makes the thing an absolute hoot to ride. Is it the fastest in its class? Nope. But it puts a big grin on my face. I’ve also ridden several very large, very heavy V-twin cruisers and baggers, and they also put a smile on my face, but I was laughing at the bike, not with it; although, I did once seriously consider purchasing a Kawasaki Vulcan Vaquero in a moment of weakness.
I probably didn’t answer the original question to any forum dweller’s satisfaction: I am not a mechanical engineer, and I did not ruminate on weight distribution, cooling properties, valve timing or method of actuation and why overhead cams are a thing, angles and firing order, bore and stroke, or why the power to weight of any given enormous cruiser is so low. I will tell you that a V-twin engine exists because there is market demand, and there is market demand because people love them. Motorcycles are never ridden on paper, friends.
So, dear reader: what is your favorite engine configuration? Do you think the V-twin engine is obsolete? Did I miss a “V-twins are great because” point?