Editorial: Why must motorcycles continue to get bigger and bigger?
Filed under: Etc., AutoblogGreen Exclusive, On Two Wheels

There were many reader responses on our editorial regarding the ever-expanding volume of the automobile in America, so why not extend the same questions to motorcycles? Way back in March we featured an article which highlighted the fact that technology is trickling down to motorcycles from cars. There has been a great deal of debate going on as to whether or not motorcycles are really a green form of transportation. This post will not hit each and every facet of either side of the argument, but it is interesting to note that it is possible for manufacturers of motorcycles to hit extremely high horsepower figures while still allowing for reasonable fuel economy.
Unfortunately (or fortunately, depending on your point of view), delivering on the promise of that fuel economy is in the hands of the rider, and when big power is available, riders are likely to twist that wrist ever tighter! So, it came as little surprise that Cycle World was able to wring 45 miles per gallon out of one tank with their Kawasaki Concours 14 testbike, while lowering that number all the way down to 24 miles per gallon from another tank-full. That is a huge disparity, and shows that high power and high fuel economy are possible from the same engine, but not at the same time. The engine in this particular bike happens to be one of the most powerful available in any production bike, maxing out at almost 140 horsepower at the rear wheel with 92 lb. ft. of torque. From a 1.4 liter engine, this is excellent! To make that kind of power, the engine has variable valve timing and electronic fuel injection. The engine also makes full use of its 10.7:1 compression ratio, which is quite high, and 4 valves per cylinder arrangement. This is an excellent engine, and would make an awesome starting point for a hybrid vehicle. But, there it sits installed in a motorcycle!
Continue reading after the jump.
Consider, for a moment, that motorcycles are getting ever larger. The Frankfurt Motor Show that we have been covering this week has shown that even in Germany, the land of high performance and no speed limits, cars are being forced into going green. BMW, Mercedes and Audi are powerhouse carmakers in Germany with a penchant for producing high horsepower cars, but they chose to feature hybrids and diesel engines for this show. The same cannot be said of motorcycles, however. Bikes like the Concours 14 and Triumph Rocket III show that buyers want bike engines in their bikes. Those big engines do come with big power, and that's fine. There is no problem with having a high performance vehicle. The problem with cars is that those cars are used for purposes where that power simply is not needed. On a much smaller scale, the same is true of bikes - I can't think of any scenario where a rider needs the power output of the Rocket III's 2.3 liter engine. That engine would be just fine in a small car, and is complete excess in a motorcycle.
So, getting back to whether or not motorcycles are a green form of transportation. The answer is that they can be. Of course they are not always used for commuting back and forth to work. But, for commuting purposes, they make a fine choice. Not only can money be saved when filling the tank, emissions can be saved as well. Studies have shown that riders of motorcycles spend less time with their engines idling and more time on the move, shortening the time that the engine is running in the first place. Less space is taken up with the bikes are parked and congestion would be much less of a problem with more cycles and less cars on the roadways. We would never suggest that all of our readers rush out and but a bike for commuting, but for those who can make it work, riding to their jobs offers many advantages. Perhaps you should shy away from the Concours 14 for your commuting chores, though!
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Reader Comments (Page 1 of 1)
9-13-2007 @ 2:51PM
detroit9000 said...
Dear Adam Smith,
Why must the supply and demand curve govern the marketplace?
Reply
9-13-2007 @ 3:16PM
Brian W said...
A high-revving, relatively low torque motorcycle engine is the absolute last place you want to start for a hybrid car. Ideally you would utilize a small turbo-diesel with low power and higher torque.
Reply
9-13-2007 @ 4:09PM
pgh said...
What's really going on here is that since the beginning of the malaise era, motorcycles have been the place where regular folks can experience big power. How many of us look at cars such as the BMW M5 and AMG Mercedes offerings knowing that we will likely never own any car that powerful. Yet for not a lot of money at all we can ride motorcycles that exceed all but the most powerful of four-wheelers. Until speed goes out of style, this trend will certainly continue.
By the way, while I agree that the Kawasaki Concours motor may not be a good match for hybrid applications, accoring to a recent test it turns out to have an exceptionally flat torque curve. Personally, I'd be happy to have one as my next two-wheel powerplant.
Reply
9-13-2007 @ 4:10PM
MattM said...
In my experience, (and perhaps this is not true in other parts of the country) motorcycles are not for transportation; they are for recreation and style. The most important thing about a motorcycle's engine isn't how powerful it is or how fast the motorcycle can go, it's how the motorcycle sounds. (Loud, rumble, lots of bass.)
Most motorcycle riders in this area ride on the weekends when the weather is nice. They ride for the joy of riding. The ride to see and be seen. Not to go anyplace, or do anything necessary.
It's a lot like riding a horse or sailing a boat. It has no utility, it's just an entertaining hobby. And making it more efficient misses the point entirely.
Reply
9-13-2007 @ 4:10PM
Benson Leung said...
Bryan W...
How do you figure that low torque engine is bad for a hybrid vehicle?
The engine in the Toyota Prius is a 1.5L atkinson cycle engine that sacrifices low speed torque and high end power in favor of efficiency. The system makes up for it in terms of performance with the electric drive motor, which at low speeds, can provide tremendous torque.
http://www.everything2.com/index.pl?node=Atkinson%20Cycle
Reply
9-13-2007 @ 5:02PM
Phil L. said...
A note on motorcycle engine output...
From a market perspective, people simply don't expect motorcycle engines to last as long as car engines. It's rare to find a motorcycle engine with 100K miles on it. And, in my experience, it's expected that a motorcycle engine will have been rebuilt at least once before reaching this level of mileage.
Simply stated: In general, motorcycle engines can be tuned for higher output because they have a shorter life. Would you be happy if your car routinely required an engine rebuild at less than 100K miles? Transplanting this level of engine performance into a car - without also finding ways to reach acceptable levels of longevity - won't fly in today's marketplace.
Reply
9-13-2007 @ 5:10PM
TIMMAH! said...
Higher sales margins?
Just waiting for the first bike from HUMMER...
Reply
9-13-2007 @ 6:16PM
motosaurus said...
I think you are confusing displacement ( Rocket III ) with power ( GSXR1000, R1, CBR1000, ZX14 ZX10). In fact larger displacement turning at lower RPMs can be more efficient. See the 7 liter Corvette for instance, that can get pretty good mileage if you keep a light foot. Since few bikes are ridden more than 2000 miles a year, and most get 40+ mpg they just aren't a big part of the problem.
Reply
9-13-2007 @ 7:05PM
Cervus said...
I have a 2004 Honda Reflex 250cc scooter that I ride to work 1-2 days per week. It comes out to about 4000 miles per year. I've ridden it in some pretty chilly weather. It's freeway legal and I get about 63-67 mpg.
Reply
9-14-2007 @ 12:26AM
stevejust said...
I have an older bike that gets about the same mileage as my hybrid civic. I really want a new bike, but I think it's pathetic that bike mileage has remained basically flat over the last 20 years. It's debatable whether car mileage has remained flat (compare a CRX HF or an 80's Corrola, or a Geo Metro to the hybrids of today. The hybrids are bigger and safer. But some might say not all that much improved mpg-wise if you don't pay attention to air bags, passenger room and stuff like that). I tend to think mileage has improved in cars far more than it has in bikes.
I considered getting an MV Agusta Brutale for a time, then found out it only gets 28 mpg and took it off my list. I
I'm not the only person who rides a motorcycle and thinks they should get better mileage, detroit 9000. If a manufacturer put out a bike that was designed to be more environmentally friendly, it could fill a niche market. Adam Smith would approve. Right now, the closest thing to an environmentally friendly bike is a BMW 650CS.
In the meantime, I'll just wait to see what the 08 Ducati Monster looks like, and hope that it will get about the same or better gas mileage than this year's.
Reply
9-14-2007 @ 4:27AM
spdracerut said...
The current crop of sportbikes (600cc-1000cc) get roughly 35-45 mpg depending on throttle usage. And the 1000cc bikes are putting down close to 160hp at the wheels :)
I'm in France right now and it's amusing to see a Honda Goldwing with a 1.5L motor sitting next to a car with a 1.4L turbo diesel.
Back home, I use my motorcycle to commute to work 2-3 days out of the week. It saves me roughly $2 a day compared to driving my car. If I were in Europe, that'd convert $6 a day; almost $9 a gallon for premium over here!
Reply
9-14-2007 @ 9:35AM
Syke said...
I've been riding for 31 years now, average 10k a year (used to be 20K) of virtually year round riding, bikes are my main daily transportation, and my '95 Triumph Trident has 96K on it - and no, it's not ready for the junkpile.
It gives me a steady 36mpg (the first generation Hinckley Triumphs were known for being gas hogs). My Harley does high 40's. And fuel mileage is a minor part of the equation. Performance and driving enjoyment are the important parts.
Yes, you can easily make a 65mph motorcycle. It'll probably have a 250cc engine, performance just slightly faster than a Camry with automatic, and be very undemanding. Honda makes those bikes right now, they're called Rebel and Nighthawk.
At the dealership where I work, they sell barely enough to justify keeping them in the catalog. If bought, it's by a very prudent beginner (very much in the minority), and sold off within a season, as the owner has progressed to the point that he/she's bored with it and ready for something bigger.
Reply
9-14-2007 @ 9:58AM
Alex said...
I agree that you can easily find a bike whose's engine isn't going to last anywhere near 100,000 miles, but you can just as easily find ones that can.
It's all about the ratio of HP to cc's. My FZR1000 is a high strung sports bike. Its brually fast and immensely quick. But an engine that size with that much demand put on it won't get good mileage or last very long.
HOWEVER my little KLR650 puts out little power in comparison. That bike will go forever and it gets great mileage.
it all depends on what bike you are buying and why you are buying it. If you buy something like a GSX-R, a Speed Tripple, or a 998, don't expect to get impressive mileage or an engine built for longevity. If you get something that has greater displacement compared to its power output you'll get great mileage and an engine that is not so stressed that it can't survive to 100,000 miles.
Reply
9-14-2007 @ 10:40PM
MikeW said...
Kawasaki doesn't have variable valve timing, it has camshaft profile switching.
How many motorcycle engines have any provision for exhaust gas recirculation, I don't know of any.
Even the Corvette doesn't have it anymore, it relies on its tall 6th gear.
You can find plenty of 100,000+ mile motorcycle engines, just look for the ones with separate engine oil & transmission oil.
Reply
12-14-2007 @ 8:12AM
vtrider said...
I had a Suzuki DRZ400SM (Street legal) that got 60-65mpg regularly no matter how hard i rode it. My current KTM 640A gets 50mpg. Kawasaki KLR650 owners report 50-55mpg regularly. Plenty of bikes getting this type of gas mileage.
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