It is easy to take a look at today’s high-performance motorcycles and assume all of the features present have been there since the very beginning. From the sleek suspension systems, beefy brake components, and powerful and reliable drivetrains, it all appears to be perfectly balanced. However, what you are actually seeing is the latest evolution of sport bike technology. Things weren’t always so advanced. If you were to take a look at bike from as little as ten years ago, you would be surprised to see how far today’s standard has come. If you were to go back 25 years, you might not even be able to recognize a bike as having sporting potential at all.
This list is comprised of some of the most defining technologies to ever grace the sportbike arena. Once these items showed up on the racing circuit it was only a matter of time when they would be front and center in the dealer showrooms. This isn’t a ranked list; no liberty was taken in assuming one was more important than the other. This list is simply a representation of features that a consumer should expect to find in a modern sportbike. Once novel and the height of ingenuity, a quick browse through your local dealer will prove that these designs are now commonplace.
Fuel injection systems are certainly taken for granted in today’s market, but it may come as a surprise to some that this technology isn’t all that ancient for mass-produced motorcycles. It wasn’t until the early 2000s when the ol’ choke lever was thrown out to pasture. Fuel injection has made cold starting a breeze, allowed for dynamic fueling at varying altitudes, and provided a more efficient fuel burn. Tuning can be accomplished with a simple software change instead of guessing and checking with jets and needles. While many will stand by the carburetor’s pure simplicity, it’s hard to argue with the precision and maintenance-free demeanor of a well-designed fuel injection system.
Performance motorcycle frames have come a long way in recent years. Some bikes on sale today hardly even have a frame at all, utilizing the engine as the main-stressed member. A design that is a hallmark of the modern sportbike is the perimeter (a.k.a. “dual-spar”) frame. Increasing chassis rigidity while decreasing weight, these sculpted channels of aluminum are a far cry from the crude cradle frames of old. Many perimeter-style frames are easy to spot, as the thick side walls running the length of the gas tank are a dead giveaway.
If you have ever stared at the brake rotors of a high-performance motorcycle, you may notice that the center part is typically a different color and material than the outer portion. While the design looks slick, there is a practical purpose. The inner “carrier” is a separate piece from the outer “rotor”. The two pieces are joined together with metal rivets. As a result, the brake rotor is not a singular rigid piece. This design allows the rotor to expand and contract separately from the carrier to compensate for heat cycles experienced during heavy braking. It also allows the rotor to move slight off center to track truly in the brake caliper. When it comes to slowing down a fast bike, semi-floating brake rotors are a must-have.
The brakes on modern sportbikes can pack a serious bite; so much so that under high-load braking the caliper mounting configuration can flex. While this may be something that will only be experienced during extensive professional use on the track, it hasn’t stopped manufacturers from incorporating a more sturdy design into their production bikes. This new setup is known as radial-mounted brake calipers. The defining part on this design is the orientation of the caliper mounting bolts. On a radial setup, the caliper bolts are parallel to the braking surface (the pads & rotors). The old design had the caliper mounting bolts perpendicular to the braking surface, which could lead to a small amount of torsional twist under severe load.
USD (Upside-Down) forks have adorned the front of true sportbikes for a few years now. Compared to conventional forks, USD forks provide greater rigidity due to the increased diameter of the fork legs. The triple-tree mounting locations (at the top of the forks) also have a larger surface area to clamp on to thus increasing rigidity ever more. Another benefit over conventional forks is the lower unsprung weight as the damping mechanisms are located at the top of the forks, closest to the chassis.
Quick downshifting without a delicate feathering of the clutch lever or a perfectly-blipped rev-match can see your rear tire taking a different line than your front. At best you’ll get a nice looking rear slide, at worst you’ll end up with a low-side. This scenario is especially common when you find yourself downshifting from a high RPM while entering a corner. When downshifting, you are forcing the engine speed to catch up to the relative wheel speed for the specified gear. Since there is a sizable rotating mass inside the engine, the engine is unable to immediately catch up to the wheel speed. As a result, the lower engine speed forces the rear wheel to rotate slower than the relative road speed, therefore inducing a skid. A slipper clutch systems works to isolate this lag in engine speed. It has an internal ramp-style mechanism that allows the rear tire to maintain relative road speed while the engine speed gets a brief moment to catch up.
Sorry, no picture for this one. You can’t really see them but you certainly can feel them when downshifting.
Preload, rebound, and compression are the basic attributes needed for a for a fully-adjustable suspension system. A true sporting motorcycle has this trifecta which allows for the personalization of both the forks and the rear shock. A simple set of tools is all that is required to turn a soft and compliant road bike into a taught and agile track weapon.
Head shakes and tank slappers are the bane of high-performance motorcycle riding. Nothing can end a fun day faster than a trip on the whipping willy. Modern superbikes produce well in excess of 150 horsepower. Wheelies tend to happen – sometimes unexpectedly – and if the front tire doesn’t return to Earth in correct alignment with the rest of the bike you may find your handlebars violently trying to throw you off. Improper suspension set up while riding on imperfect surfaces can also lead to this scary situation. The best protection against this is a steering damper, which slows the handlebar oscillations to a controlled movement.
Gone are the days of the long “U” shaped piece of extruded boxed metal. In its place are beautifully crafted geometric swing arms that provide extra stiffness. A motorcycle’s suspension can experience loading in a multitude of ways, including while the bike is fully leaned over. A braced swing arm ensures that there is not too much lateral flex at extreme lean angles. Mate that with the extreme power that modern bikes can produce and you’ll find that a braced swing arm will also keep the rear axle in true alignment with the swing arm pivot point.
There have been a number of technological changes over the years that have moved the high-performance motorcycle benchmark forward. Some of these changes are hardly noticeable to the untrained eye, but all play a very important role in performance. These features encapsulate the evolution of the high performance motorcycle and their commonality further defines what makes a sportbike a modern sportbike.