Comparing v-twin with straight-four engines

Question

This isn't really on-topic for "motor vehicle repair", but I figure it's kinda close.

A few months ago, I bought a 1983 Honda Nighthawk 550, which has a straight-four engine. A friend of mine was looking at motorcycles also, but ended up buying a gently used 1800cc V-twin. I went to the dealership with him and asked what size he should look for to compare to mine, and the guy said mine would compare to a 1100 V-twin.

I'm curious because he was a commissioned salesperson and may have been trying to upsell my friend, or he could have been right. My dad also rides and has a Kawasaki KZ900, and sitting on it, it feels a LOT bigger than mine.

Thanks guys!

Answer 1

Generally speaking, twins will generate less power than an inline 4 with the same engine capacity. This is especially true for cruiser type engines (as opposed to a short-stroke twin like in a ducati). Simply put, twins tend to have a long stroke which gives them strong low-down torque but make it harder for them to rev (power = torque x rpm). Further to this, cruisers weight a lot - I was vaguely interested in a HD XR1200 until I read that the thing weights 250kg, that's a good 50~80kg heavier than a standard litre bike, let alone a sports bike.

There is not going to be a direct comparison. A 600 sports bike will outrun and out manourver a 1800cc cruiser but the guy on the cruiser wont care - that's not why he bought his bike.

I used to own a Kawasaki ZR750 - equivalent to a Honda Nighthawk 750. Even when it ran on three cylinders, it was a great bike. A 550 should have enough power to have fun - I really used to enjoy riding my wife's 250 since you actually had to plan your gear changes to keep the revs up.