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Sorry, I am not that mechanical minded. I will be looking for a new bike in a few months, and I was wondering whether to buy a single or twin cyclinder. I am not sure what differences there are other than another cyclinder.

What are the pros and cons of each? At first glance, it would seem that one cyclinder would be easier/cheaper on maintenance than two.

Two of the bikes that I was considering are the Kawasaki Vulcan 500 (a twin) and the Suzuki S40 (a single). What is surprising to me, is that the S40, which is about 655 cc, has a more cc, weighs about 87 lbs less, and cost about $650 less. In this case, the single is bigger, less weight, and costs less. The choice seems like a no brainer, but then I don't know what the pros are for having a twin.

While the merits of the Kawasaki vs Suzuki is probably interesting. I am really looking for a discussion on one cyclinder vs two.

Thanks,

Dan

You're talking cruisers [not really my experience] but generally the same as standards and trailies.

In my own opinion I'd rather have a twin than a single, but you describe a good dilemma. I've ridden a 450 single, and 500 twin. I'd rather have a twin for smoother power. Just as I'd rather have an inline 4 to a twin for smooth tractability from low RPM that twins seems to shake around at. But at the expense of more weight, higher cost?

I don't include a power comparo, but you may find that the 500 twin produces simliar power (if not torque) figures to a 650 single. Because a single produces fewer power pulses in the same time, singles tend to have longer stroke geometry (more torque to get the bike moving), with a result of reduced RPM range, and lower high end power.

Reduced complexity should reduce initial cost, and repair cost of a single cylinder engine.

I've probably missed something. Hope this is a start!

The simple rule of thumb.... the more cylinders in an engine gives a smoother performance and greater power....

Fast Eddy gave a great explaination......also a great article to read on this subject

Whats between your legs

Nice overview of motorcycle engines, performance, power etc....

Is insurance costs an issue in the decision.....if there is even a difference?

I had the same decision to make, I went with the Vulcan 500, partly because at the time no one had any S40s, but also sitting on one of the last 500s in our area (I bought new) it just felt right. Even tho I have never ridden an S40, I am very, very happy with my 500.

The Vulcan 500 is the more substantial motorcycle with greater highway potential. It's virtually the same engine that Kawasaki uses in the Ninja 500. It will likely be smoother as well.

High_Side wrote: It will likely be smoother as well.

The Kaw 500 is quite a bit smoother. The S40 (it was an LS650 when I rode it) is a traditional thumper. No one really expects it to be smooth on the highway and it doesn't disappoint. The 500, on the other hand, is a quiet, water cooled, counterbalance twin. The only way it would be smoother would be if they made it a 4 cyl.

That said, I've gotta admit that I thoroughly enjoyed riding the S40 around town. Lots of low end torque, and pretty zippy at street speeds. The 500 makes a better highway mount (IMHO) not only because it's smoother, but it also has more power at highway speeds.

The single is rougher, vibrates more because when the cranksaft goes around there's not as much to counterbalance it. Singles, commonly called thumpers, can rattle the fillings out of your mouth, and vibrate sufficiently to give you tingly fingers after a couple of hours riding. Of course paying for a more expensive BMW will give you a nice counterbalancer. Singles have less horsepower than twins, less heavy, burn less gas, are easier to maintain, and are usually cheaper. Most small bikes under 250cc, and the huge majority of the world's bikes in 3d world countries are singles.

Twins have 2 cylinders that somewhat counterbalance the cranksaft when it goes around, resulting in a much smoother, more comfortable bike. The comparison to a single can be startling for a rider that moves from a single to a twin. Moving to 4 cylinders from a twin, you wonder if the engine in still running. Twins have more power, are heavier, more expensive, eat more gas, and provide more performance.

It really depends on your riding style and the purpose of your riding. The S40 Savageis a single 650 but puts out 40HP, weighs 360lb, and gets 60MPG. The Vulcan 500is a parallel twin and puts out 50HP, weights 410lb, and gets 50MPG. The single gets less power for its engine size, is substantially lighter and gets much better gas mileage.

That said, both bikes are exceptional. You really need nothing more than a single if you are commuting. If gas cost is high on your list, a single is much better. If touring or highway riding is important, you'll be more comfortable on a twin. If you want more acceleration then go for a twin. Between the 2 bikes I'd go for the Kawi EN500.

Here's a ten bike comparo from the 03 Cycle World Buyers Guide that includes both the S40 and Vulcan 500. The Vulcan 500 is the better performer of the two while the S40 is around 90# lighter. Gas milage is about the same. I've been considering one of the two as a next bike.

http://smg.photobucket.com/albums/v443/ ... sOnWheels/

While on the topic, I remembered that there are single cylinder machines designed for high revs. They have a 70-81 mm stroke, compared to 42.5mm for a CBR600RR. This is in F650GS range. But check out the mods.

For every taste there is a perversion. Here is one more:

http://www.barebones.net/machines.htm

It was explained to me long ago that the more cylinders a vehicle (car, truck, motorcycle) has, the less work each cylinder has to do in order to keep going. I may be WAY off with motorcycles, but I do know that with trucks, a four cylinder Ford Ranger, driven hard, will give up faster than an eight cylinder Ford F-150.