Best Sport Motorcycle Tires of 2017
In this video/article :
- Metzeler Racetec RR
- Bridgestone RS10
- Bridgestone S21
- Pirelli Diablo Rosso 3
- Continental Sport Attack 3
Metzeler Racetec RR
Same as last time, we’re rolling from track-focused to road-biased. In 2016 my fastest pick was the Pirelli Supercorsa but this year – Metzeler Racetec RR.
So I cheated a bit, because the Racetec RR is a sister tire to the Supercorsa. Pirelli owns Metzeler, they share factories, one says spaghetti the other says spaetzle but in the end both tires are quite similar.
Main difference is that Pirelli focuses on short circuits while Metzeler is all about road races. RR – road race – get it?
So that’s one of the trickiest things to design a tire for. Take the Isle of Man TT – we have elevation, temperature and abrasion changes, plus an incredibly long lap at race speed. The demands are versatile and this Metzeler was diverse enough to see the top step.
For starters, it comes in three different compounds. The K1 is supersoft, but there’s also a soft K2 and a medium K3. 1 and 2 are race-ready tires, but K3 is more of a road rubber, which will lose you a second per minute at the track.
Like all fast tires, the Racetec RR is turning my hands black. That’s how much carbon is in here – an additive that makes for soft, sticky, fast-warming rubber.
Not a long-lasting one, however. Expect to get about four track days from the rear, which always wears away on the sides first. Since I’m a cheap bastard, I would then use it on public roads for another 1000 clicks to burn what’s left off the top.
Speaking of tops and sides, the Racetec RR has little of one and much of the other. It’s a high-narrow profile, meaning you won’t get much surface area on the straights, which probably explains why the Racetec RR tends to break traction off the line.
But the thin centre band also makes it shockingly quick to fall in. And once it does, the contact patch is massive.
At the very limit, Racetecs are a smidge more stable than Supercorsas and loads more stable than the older Interact. That’s because of a stiffer rayon carcass, which offers rigid precision at low lean angles.
But be careful! This Metzeler won’t get squirrely at the limit of grip, so you’d better know where that point is.
Racetec RRs aren’t for the fainthearted. They’ll run circles around Dunlop Q3s, they’ll track truer and lean quicker than almost anything with a DOT sticker. But make sure you know how to pick a line, because this tire will hit it with ruthless precision.
Bridgestone RS10
In contrast, the Bridgestone RS10 is more forgiving.
It has a softer sidewall, so the tire doesn’t leave all the damping to my suspension. Put simply, the RS10 spends more time on the pavement than the Racetec RR.
And that’s a good thing because I’m not Maverick Vinales. My tires aren’t constantly loaded under acceleration or braking, as I’ve been known to miss a marker. I often have to adjust my line mid-turn, and sometimes I even blow a shift.
All of those things put an awkward impulse on my tire, but the Bridgestone RS10 doesn’t care! It’s soft enough to soak up my mistakes.
Of course a cushy sidewall also makes the feedback more vague, but you can’t have your doughnut and eat it too.
Normally I’d expect a soft sidewall to hurt cornering precision as well, but Bridgestone pulled two clever tricks. First, they cut tread grooves with shallow edges. So when I have my tire leaned over, the lateral force is trying to fold this shallow slant onto itself, which will never happen, so the block stiffness is huge.
Then Bridgestone also chucked a GP Belt in here. That keeps pressure on the centre of an oval contact patch, which is an area that otherwise tends to curve away and give up grip.
Bridgestone is rather secretive about how the belt works but if I had to place a bet, I’d say they modulated the belt tension to be tighter at mid lean angles. That keeps a uniform pressure on the contact area, which increases precision when you’re lining up a curve.
Also take note of these mid-lean reservoirs. The RS10 can evacuate a wee bit of water, so compared to the Racetec RR it’s slightly less of an ice skate on wet pavement.
Overall, the RS10 is more street-focused than the Racetec. It’s perfect for canyon carvers who like to hit the track maybe 2-3 times a month. In that sense, this is very similar to the Dunlop Q3 I recommended last year.
But the RS10 gives a vastly superior front end feel and it doesn’t have the rear overheating problems of the Q3, so you can push it a little harder on race day.
Just make sure you give the RS10 a lot of time to warm up because it slides way more than the Q3 at low temperatures.
Bridgestone S21 & Pirelli Diablo Rosso 3
So far we’ve seen an aggressive and an amateur track-day tire. But with the Bridgestone S21 and Pirelli Diablo Rosso 3, we’ve moved to primarily public road usage.
Maybe take these to the circuit once a month, provided you don’t mind sacrificing a few seconds.
And if you can only take one, make it the Pirelli. This is a faster tire than the S21 because the profile is steeper. Also it’s only a double compound rear with a thin 20% centre band. That means you’ll get soft cornering grip even from early lean angles.
Speaking of which, the two compounds are both silica based. 100% on the sides, 70 on top. That means the Diablo Rosso hooks up well in cold, damp conditions. Plus it has grooves that actually extend into the centre strip for water evacuation.
The Bridgestone S21 is equally good in the rain. Had Bridgestone cut these micro sipes a little deeper, they probably would have trumped Pirelli on the wet stuff. But alas, these disappear within the first 500 kilometers so they’re basically useless.
But the S21 does last a lot longer than the Diablo Rosso. Its tread grooves are deeper and the rubber is a triple compound, which lets Bridgestone use a harder material where the tire spends most of its time.
I’d expect an extra 2000 clicks with the S21 when compared to the Pirelli. It also gets about 1000 more than the S20 EVO, which is impressive considering that it laps 2 seconds faster than the old version.
Both tires have a shortcoming! For the Diablo Rosso, it’s sidewall stiffness. Rayon should be decent but the tire came out surprisingly soft and squirelly at the very limit, especially on litre bikes.
And the S21’s main problem is its profile. See Bridgestone made the rear wider and flatter, which improves upright surface area for straight-line grip, stability and longevity. But that also makes the S21 reluctant to turn in and slippery under cornering acceleration.
Bridgestone gave the front tire a higher and narrower profile to counteract the slow turn in, but it still takes a fair amount of effort. And of course that does nothing to touch the problem of rear exit grip, so the S21 likes to spin up when you’re on the throttle coming out of a corner.
All around, these are the best two tires for the way most sport riders ride. Choose the Diablo Rosso 3 for better performance, especially on that occasional track day. And take the S21 if you want more miles for your dollar.
Continental Sport Attack 3
Now, let’s end this list with a wet-weather option.
Last year it was the Metzeler Sportec M7 RR, which is still a great tire. But this year I’ve chosen the Continental Sport Attack 3.
Surprise, surprise.
The Sport Attack 2 was generally unimpressive. Not that great in the dry, nothing special in the wet … nobody cared.
But Continental has done something radically different with the Sport Attack 3. They’ve created a solid rain tire by mixing a finer silica compound and extending drainage out the sidewall. They’ve also kept the grooves short, so they’re less likely to bend shut under pressure and lose their ability to channel water.
So big whoop – right? We didn’t love the M7 RR because it was safe in adverse conditions, we loved it because it was stupid fast in adverse conditions.
What can Continental say to that?
Well, they say “MultiGrip Technology.” Basically this is a single rubber compound that has been cured progressively. So it gets gradually grippier as you lean to the limit, rather than suddenly changing from one compound to another. And that’s a lot easier to control.
If Continental is baking Metzeler a humble pie, the second key ingredient is GLFT – Grip Limit Feedback Technology. Basically they built weakness into the edge of the carcass on purpose so that the tire makes small slides before releasing entirely. That helps a rider to know when they’re on the limit of grip, so they can cool their jets before low siding.
And the icing on this cake is Traction Skin. Unlike other manufacturers, Continental makes a micro-rough surface right out of the mold. That all but removes the need for a break-in period, so the Sport Attack 3 comes ready to attack.
I have two annoyances with this tire! First, the tread looks like it was designed after a game of pick-up sticks.
Hey Continental – you know you can curve the grooves to help a tire wear evenly, right?
The second thing I dislike is the profile. Continental flattened the crown for better straight-line surface area and mileage – 10,000km won’t be unheard of. But the squat profile makes a sluggish turn-in, and I’ll be the first to admit that the M7 RR is more flickable.
However, I still think that the Sport Attack 3 is an easier tire to ride in crappy conditions. If you want to maintain an aggressive style over rain, ridges, dirt, dust, pebbles and paint – it doesn’t get any better than this.
And that’s it for my favourite go-fast tires – thanks for watching.