If there is one single component that can make the biggest difference to the overall performance of your sportbike, it’s those rubber hoops spooned around the wheels. With the ever-increasing power and handling of today’s sportbikes, transferring that power to the ground and directing all that energy around corners becomes an extremely difficult task for a tire, yet as you’ll see here in these pages, all of the latest sporting rubber currently available is well up to the task.
It’s been quite a while since we last conducted a sport tire (tires intended for street use, with a possible track day thrown in here or there) comparison test — exactly seven years ago, in fact (“Street Sense”, December 2005). Since that time, the sportbike tire market has segmented itself into increasingly specific genres. Besides the sport and DOT race tire sectors, now the street/track day and sport-touring categories have grown increasingly popular, and nearly every tire manufacturer has a specific model (some have more than one model for a category — check our “tire market” chart on page 39 for more info) for each of these particular applications.
Seven years is an eternity in the sport tire market however, so we decided a comparison test of this particular group was in order. These are the tires you would select for average street and aggressive sport riding, with perhaps the very occasional track day included somewhere in that life span. For those who get out to the track more often, you’d probably be better off with the hybrid street/track models that are now offered; we’ll be testing those, along with the latest DOT race tires, at a later date.
As we’ve done in all our previous tire comparison tests, we contacted every tire manufacturer that offered a model for this specific application, and asked them to send us two sets of their latest rubber to fit a Honda CBR600RR and a Suzuki GSX-R1000. Using these two machines not only allowed us to double up on the data and subjective impressions, but also permitted us to test the two most popular rear tire sizes: 180/55-17 (for the CBR) and 190/50-17 (for the GSX-R).
Time has taken its toll on the overall market, as two manufacturers from our last comparison have since stopped offering sport tires or dropped off the map altogether (Maxxis has ceased its street tire catalog, and Tomahawk is no longer in business as far as we know). We did have one new entry, however: Shinko tires have made a name for themselves in the past decade as a very inexpensive alternative to the more popular name brands. In fact, their cult status (and increasing market share in this tough economy) has gained the attention of the name brands, with two manufacturers specifically “re-releasing” an older model in order to offer that same economical alternative within their own lineups. We have a total of seven manufacturers represented in this comparison test: Avon, Bridgestone, Continental, Dunlop, Metzeler, Pirelli, and Shinko.
Most of you are surely wondering why veteran manufacturer Michelin wasn’t included in this comparison test. The reason is that the timing of our test was just a little too early to allow Michelin to get us its brand new sport tire that will be making its debut soon after you read this. The Pilot Power and Power 2CT will be replaced by this new tire, thus precluding us from using either of those models. We’ll be getting some sets of this new generation Michelin sport tire soon, and will give you the lowdown as soon as we’re able.
As before, each model was weighed, and its sidewall and tread construction noted. After the tire was mounted, the circumference, sidewall height, and section height and width were all measured; this data is all listed in the chart on page 38. We made any chassis ride height adjustments to compensate for any differences in overall circumference heights only if the test riders (Editor-in-chief Kunitsugu, who rode the CBR600RR, and Associate Editor Bradley Adams riding the GSX-R1000) felt it necessary by adjusting spring preload in the front.
As shown in our data acquisition sidebar on page 40, the test loop this year was different due to the relocation of our editorial offices to El Segundo, California. The 130-mile test loop still includes a good mix of urban city, highway, and canyon curvy roads snaking through one of the many mountain ranges in Southern California, taking about 3.5 hours total to traverse on average. The variety of corners on this loop is easily a match for the previous one; everything from smooth and grippy to choppy and dirty pavement, fast corners, slow corners, elevation and camber changes that challenge every aspect of both a tire’s and rider’s performance, hard braking, trail braking, changes in tarmac — you could say that this loop has it all.
As before, while we’d like to say we included wet weather testing as part of this comparison, unfortunately rain in the late summer in Southern California is basically nonexistent. Regardless, it’s extremely difficult to conduct repeatable, reliable wet test parameters with the resources we currently have.
At the completion of each test loop, Kunitsugu and Adams each filled out a ratings sheet that included 30 parameters in four different categories of performance: general, braking, traction, and steering. General characteristics include break-in and warm-up time, feedback, predictability, compliance, stability, and confidence among others. Braking characteristics include feedback, predictability, stability, and mid-corner behavior. Overall grip was rated on smooth and bumpy pavement, at maximum lean, and in slow or fast corners; and steering was graded on categories such as effort, neutrality, precision, and linearity, among others.
Um…where’s the racetrack testing?
We’re sure some of you out there are wondering why we’re not including racetrack lap times as a measurement of these tires’ performance. For tires that are specifically intended for that environment such as the sport/track day or DOT race categories, that would normally be the case. But the main reason we don’t here is because the vast majority of these tires that are sold will only see the street for their entire life span. Using racetrack aggression levels and speed to measure a street tire’s performance and feel is unrealistic, because the tires will likely (and hopefully) never experience those upper-envelope speeds and ultra-aggressive usage on public roads; this test is meant to measure the performance of the tires at speeds that are much more relevant to those that they will see on the street, which is a completely different setting than the controlled environment of the racetrack.
Make no mistake — most of these tires would not be out of their element for the occasional racetrack foray. The overall performance of this category has risen by leaps and bounds in seven years, and quite truthfully, you would have to be riding at a pace on public roads that borders on reckless to really need a tire with better grip. Yes, DOT race takeoffs from the local racer are probably cheaper, but it should be remembered that those tire compounds are made to endure only one or two heat cycles (both of which were probably used up before they were re-sold), and overall grip won’t be the same as when they were new (nor will the tread on the sides, mostly torched from numerous hard racetrack laps). And there’s no need to go into how foolish running racing slicks on the street is…
For each tire, the SR Rating is based on the average of all the scores for that tire (30 total ratings, from a scale of 1 – 10). There are four ratings categories: general, braking, traction, and steering. The scores in the capsules are the averages of those scores in each particular category from the aformentioned sub-categories and are displayed for both the 600 and the 1000.
As always, we urge you not to just blindly go with the tire with the highest overall rating, and instead read the capsules and the riders’ subjective comments to find the right tire for the type of riding that you do and the makeup of the roads in your area.
You’ll also note that the section dealing with tire pricing has changed from our usual policy of just listing the manufacturer’s suggested retail price. Because price fluctuates so much between retailers, we decided to average the listed prices from a handful of popular online motorcycle accessory chains, and come up with a number that way. We feel this more accurately reflects what you’ll find when you go shopping for tires, whether through a traditional brick-and-mortar bike shop or through an online source.