Tested: Pirelli Diablo Rosso III tyres

WORDS: John Milbank, editor Motorcycle Sport and Leisure – PHOTOGRAPHY: Milagro

Price: Around £240 a pair

What better way to test a tyre that’s claimed to be perfect for UK riders of sports, naked and sport-touring bikes than in the pouring rain?

I’m sure that, in 20°C heat on a sunny Spanish race track the new Pirelli Diablo Rosso III tyres would be absolutely stunning; the evolution of the excellent Rosso II, which I’ve used on my favourite (fast) British roads, and on Cadwell (in the dry), the new rubber promises increased grip and mileage. But it wasn’t to be – Aragon was covered in standing water, we were all soaked, and yet we were still all utterly impressed.

The Diablo range was launched in 2002, with the Rosso II (which will still be available) hitting the market in 2011.

The optimum mix of handling, grip and consistency across operating temperatures is usually achieved via the profile, structure, compound and tread pattern. By increasing the tyre’s centre (or ‘cap’) height by 5%, and increasing the side’s radius by 7% over the previous tyre, the Rosso III gives a larger footprint when cornering. The company claims that in testing, the Rosso II had an optimum 45° lean angle, while the III achieves 52° (the more track-oriented Diablo Supercorsa has 58°).

Grip has been improved by using a 100% silica compound in the front, along with a dual-compound rear, which has a high-silica mix across the central 20%, and 100% silica on the rest of the tyre. Using a full silica compound used to mean good wet performance, but limited consistency at prolonged, higher temperature; however a new blend promises performance across all conditions and surfaces – including track – whilst gaining a 15% mileage improvement over the Rosso II.

Changes to the tread pattern maintain the trademark flash design, but there’s now 9.5% tread area across the front tyre, and 7.5% across the rear, compared to 10.5% and 8% on the Rosso II. The pattern creates water drainage, but also aids in the compound’s warm-up, as well as optimising the tyre’s footprint.

A revised structure is also designed to absorb road bumps and aid the tyre’s warm-up, as well as creating a more even wear across the rubber’s life.

Putting them to the test

The morning of the Rosso III launch was on a mix of long straights, tight twists and sweeping bends covering 100 dry miles from Motorland Aragon to Olocau del Rey and back. My first experience of the Pirellis was with a Yamaha MT-07 – a softly-sprung bike, it was still immediately obvious that the tyres very effectively soaked up minor imperfections in the road. Deliberately aiming for cracks and small pot-holes, the ride was smooth and compliant; some tyres can feel a little firm, transmitting vibrations and knocks through the bars, but – surprisingly for such a sporty tyre – there was none.

By swapping machines whenever possible, I also tried the Diablos on a BMW S1000R, Ducati Hypermotard SP and a Honda CB650F. In every case, the motorcycles tipped into bends very easily, changing direction without effort. While the radiuses now offer a sportier profile, there was still what I consider a very neutral feel – something I much prefer to the almost Toblerone-shaped sports tyres of old.

Conditions were fine, and while the pace wasn’t flat-out, it was still spirited. During the photo stop, we had to wait a fair while between passes of just two corners – no time to get any real heat into the tyres, and plenty for any there was to fade away. Riding the S1000R, it still felt completely at ease, and as I found myself half-way around a bend going faster than I’d realised, the BMW tipped further without any difficulty. My favourite tyres are those that seem comfortable at any angle, and the Rosso III, like its predecessor, never appears to want to drop deeper or pick itself up.

As we arrived back at the track, the rain started. By the time we were out behind the safety car for a sighting lap, the persistent rain was leaving standing water at many of the exits of the fast circuit’s corners. I’d chosen a BMW S1000RR – in rain mode the throttle delivery and restriction to a paltry 185bhp made me feel more confident. I figured that choosing this over the Honda Fireblade that was also available would mean that if things did go a little wrong, at least I’d know it by the warning lights and a smaller twitch, rather than chucking myself across the Tarmac.

Surprisingly though, the Rosso III proved totally stable. Never once twitching or causing any errant lights to blink on the dash. As my confidence increased I’d carry a little more speed in, and demand a bit more acceleration out of every corner.

I’m no racer of course, so there were others going faster than me on the track, but they echoed my surprise at how secure the Pirellis proved in the wet. In conditions that would have seen the World Superbikes that had raced here the day before shod on full wets, the only mention of any slides was on the position marker paint of the start/finish straight, or at throttle openings way beyond what any normal person would be using on the road. Also, while I was braking earlier than the race guys, I found myself scrubbing off much more speed than I’d have needed to, again without any fuss.

This is a product superbly suited to the UK; a great tyre in the dry with very easy handling that inspires just as much confidence in the wet. For sporty road use at weekends, with some long trips and commuting, not to mention the odd track day thrown in, Pirelli’s Diablo Rosso III has struck a perfect balance.