Tyres: the final say in whether we remain upright or kiss the tarmac, and an ever-subjective topic for every one of us. Rubber technology and R&D has been drastically enhanced recently to cope with the demands of the latest crop of 200bhp howitzers and, such is the grip on offer, only human (sometimes subconscious) or mechanical errors are the cause for crashing nowadays. You really have to be a monumental bellend to unearth any grave deficiencies in top-shelf rubber.
Metzeler – the only tyre manufacturer to produce solely motorcycle rubber, which is a neat little factoid – launched the Racetec RR at the end of 2014, and its immediate success was evident in pure roads competition. We tested the K3 version which, despite racing heritage and connotations, is purely a road tyre and very different from the softer, grippier K1/2 compounds. Incidentally, the softer Racetec compounds are the first Metzeler race tyres to be properly homologated for road use, but the K3 is far more suitable for the everyday usage.
The longstanding Pirelli/Metzeler conglomerate has caused some confusion, and there’s a common misconception that the Supercorsa and Racetec are near-identical tyres that are simply rebranded, which is utter codswallop, even more so after the marketing decision to steer Metzeler towards pure road racing and Pirelli’s focus to short circuits, and subsequent offshoots in development.
Along with its sister hoop and only true ‘rival’ – Pirelli’s Supercorsa SP – the K3 has been a popular choice for manufacturers to choose fit for OEM fitment. We spent a day spanking Baron’s K3-shod KTM 1290 Super Duke R at Silverstone that included six 25-minute sessions without tyre warmers. The KTM’s switch to K3s was also a pertinent test after a life spent on the OE Dunlop Sportsmarts.
Warm-up time is impressive, even in cold conditions. There are no hidden surprises in brand-new guise and within a lap of Silverstone’s International layout, confidence to investigate kneedown came intuitively. The KTM felt instantly more assured mid-corner on the side of the tyre, more eager to steer to an apex, and more willing to accommodate trail braking over the Dunlops. If this was a blind test, we could well have been on competition rubber during our first laps.
Having spent 12 years racing in the BSB paddock and consequently on Pirelli/Metzeler rubber (not through choice, but control tyre ruling), I’ve formed an involuntary affection and unwavering confidence, although there’s a tangible shift in the RR’s behaviour. Metzeler and Pirellis have long been known for their friendly flex on the limit of adhesion but, dare I say it, the K3 feels a little more towards a Dunlop carcass in comparison with the outgoing Interact, which used to move around in excess when molested. It’s more stable in almost every aspect without sacrificing that trademark abundance in feedback.
In terms of longevity, you’ll be treated to two sessions with uncompromised grip levels before starting to observe perceptible degradation. There clearly isn’t the outright grip of its peers during acceleration from the rear but it’s all very civilised unless you’re asking for excess throttle inputs. We didn’t notice any drop-off from the front tyre throughout the day until the very end, where it felt as though it could do with another few psi. And except for overzealous off-the-throttle front-end exploitation and obvious warnings on the very side of the tyre, there’s very little to complain about. The 1290 isn’t exactly renowned for its stability, yet the palpable steering sharpness was beautifully controllable from upright to big lean, neutral and predictable.
The rear may have looked like it was attacked by a gigantic cheese grater, though this was largely down to an ill-performing Super Duke R shock and there’s plenty of road mileage left in the tank. Granted, grip levels dropped immensely from the rear during the last sessions and she moved around like a trifle, but it remained progressive and bloody good fun. The front looked nicely scrubbed and continued to produce linear performance.
Without GPS or stopwatch clarification, it’s safe to suggest the K3s lose around a second for every minute towards a lap time compared with the K1/K2. Although perfectly capable, I wouldn’t recommended them to faster, more experienced riders as an out-and-out trackday tyre unless you’re riding to said trackday, or don’t mind a slight performance expense. You simply can’t take the piss-taking liberties soaked up by the K1/2.
Away from the track, the K3s road manners imitate circuit etiquette: easy, predictable, intuitive and brag all the grip you’ll ever need for the road combined with greater stability than the Supercorsa SP. Willy-wavers and smack-talkers will have you believe that racier rubber is perfectly acceptable on the road. Unless you’re able to maintain heat and ride like a twat/boast the innate talent of someone like John McGuinness 100% of the time, the benefits of outright grip are useless.
Other than not being available in a 200-section rear option, our only real issue isn’t with the K3s themselves – it’s the fact that the M7RRs are so good in both wet and dry conditions, you have to ask serious questions before opting for the sportier tyre.