I have a friend who constantly talks about how stupid and dangerous sports bikes are. I always defend them because, in fact, they're safest bikes you can buy.
A bike is only as dangerous as it's rider. Every bike, whether it's a Honda Rebel 250cc cruiser or a BMW HP4, is capable of doing the speed limit. How much faster the rider chooses to go beyond that isn't a result of a dangerous bike, but rather a reckless rider.
The inherent differences between the two bikes are what gives the sports bike the advantage. The aggressive riding ergonomics put the rider in a position where he is better able to control both his weight and the weight of the bike. Speaking of weight, most cruisers will outweigh a sports bike by 100 to as much as 400 pounds. On the low end of the spectrum you're looking at around a 20% increase; Many full size cruisers weigh almost double what a sports bike weighs. For example, the Triumph Daytona 675R weights 407 pounds wet, while the Indian Chieftain weighs 848 pounds wet. This weight is also spread across a much longer wheelbase, making it harder to keep under control, and making cornering much more difficult. The low pegs on a cruiser also limit the available lean angle, making high speed cornering impossible. When I say high-speed cornering, I don't mean speeding. Take a country back road with a speed limit of 45. There may be some tight, decreasing radius turns that a sports bike could take at the speed limit without having to slow down, whereas the cruiser would have to. Also, good luck making mid-corner adjustments or transitioning over from corner to corner on a 700 pound bike with high bars and low pegs.
Many people associate cruisers with comfort, style and safety — and responsible adults. They often associate sports bikes with speed and danger, and reckless young people. However, this is misinformed thinking, because 73% of motorcycle fatalities occur in riders 30 years old or older. (As of 2011) Also, less than half of fatal accidents involve a speeding bike, with that percentage decreasing year after year. So while speed does kill, it's not a prerequisite.
The counterpoint is that sports bike can be less forgiving, especially high displacement models. Yes, the throttle is twitchy and a yank of the crank will arrange a date between your windscreen and visor. Yes, with that much torque and horsepower it's easy to spin the rear tire and low side coming out of a corner. However, you shouldn't riding a literbike if you haven't already made those mistakes on a 250cc. Besides, many sports bikes come standard with advanced rider aids such as ABS, TC, WC, etc. While many cruisers offer ABS, they don't offer the level of computerized rider aids that sports bikes do. But hey, at least you've got a speaker system and sat nav right?
People will also argue that while it may be less capable, a cruiser is more comfortable and not as bad for your back. The truth is, a cruiser is worse for your back, because you can't properly stand up and use your legs to absorb bumps in the road. With your back straight up and your legs out in front, each jarring pothole sends a shockwave directly up your spine as the bike jumps up underneath you and kicks you in the ass. If you're sitting on a low chair right now, spread your legs farther than shoulder width and all the way out in front of you and try to stand up. It's impossible! On a sports bike you can raise yourself up, use your legs as a suspension and let the bike jump underneath you, so your body doesn't take the impact. The also allows the bike to settle itself underneath you and regain composure. If you're looking for comfort, I'd recommend a sports tourer or an adventure bike, such as the KTM 1190 Adventure R, which very well may be my next bike if I decide against the D675R. Touring bikes are comfortable but can be obscenely heavy.
Cruisers do have their place in my heart, don't think I'm just being a hater. I learned to ride on a Suzuki GZ250 and then a Honda Rebel 250, and recently put 400 miles in one day on a rented Harley Sportster. They sound great, look great, and draw less attention.
It's just frustrating that whenever I would leave on my GSX-R, people said be careful and goodbye like it was the last time they were going to see me; when my buddy leaves on his cruiser, they say, "Have fun!"
This is the bottom line: If you're cruising along at 55 mph, and a motorist in front of you loses control of their car, wouldn't you rather be on the bike with the superior braking and handling capability? You will be able to make a sudden evasive maneuver with more ease and control on a sports bike than you would on a cruiser.
What say you, Oppo?