The Carole Nash Sportbike TT debuts at TT 2026 and, far from being a rebranding of the previous supertwin class, the new sportbikes promise to be a more sustainable and accessible entry into the TT races for many years to come.
Although seen as the junior class due to their smaller capacity engines, the old supertwins were among the costliest bikes to build, and some of the most expensive and difficult to maintain. Although based around humble parallel twin road bikes like the Kawasaki Z650 and Yamaha MT-07, the rules allowed for heavy modifications to the engines and chassis.
Unlike all the other solo classes, which allow limited tuning, supertwins which originally left the showroom with under 70bhp could get a 50% power boost in the hands of top tuners. It meant the best funded teams could build the fastest bikes, while the extreme tuning ensured that the Supertwin TT was as much a durability test for the bikes as it was a test of the rider’s skill. With high attrition rates, the Supertwin TT would always throw a surprise result or two as leading riders dropped out with mechanical gremlins.
But, for 2026, the Supertwin TT has evolved. Now called the Carole Nash Sportbike TT, it allows a new generation of motorcycle to compete on the 37.73 miles of hallowed asphalt, which makes up the majestic Mountain Course.
Competing under the regulations developed in the British National Sportbike Championship, the race will see Triumph’s Daytona 660 eligible to race alongside the ‘twins. As the inaugural year, the existing supertwins will also be allowed in under the old rules one last time – which means we shouldn’t expect too many changes at the very front of the race, but it will give us a glimpse into the future of the class and it will be interesting to see just how competitive, and reliable, those bikes built to the cheaper sportbike rules prove to be over the two three-lap TTs.
The hand-built Paton S1-R has proved to be the bike to beat in supertwins since the class began. The retro-styled Italian machines are available to buy as road bikes but, at £42,000, they’re more expensive than even the 200bhp BMWs and Hondas used in the 1000cc classes. To be truly competitive, teams further tune the engines and even change the bodywork to optimize aerodynamics – with Jamie Coward’s Padgett’s by Milenco team going as far as investing in Moto2 fairings for their entry.
Kawasaki-engined Patons have won nine out of the last 10 Supertwin TTs, with Peter Hickman’s Yamaha R7 only breaking the domination in an attritional 2023 race when two of the Italian bikes broke down in front of him. Michael Dunlop has won seven of those and the combination of him and his Paton will again be the one to beat in this week’s two Sportbike TTs. He’s been fastest in qualifying, of course, with a 123.557mph lap putting him ahead of fellow Paton rider Mike Browne, who missed out on a potential first TT win when he broke down while leading that aforementioned 2023 race.
Hickman has qualified third, sticking with his highly developed Yamaha, despite the fact that his PHR Performance company was responsible for developing the Triumph Daytona 660 as a race bike. There will be several PHR Triumphs on the grid, however they’re running under the more restrictive sportbike regulations – meaning they’re not likely to challenge the dominant Patons, or even the Aprilias and Yamahas, for outright honours.
Where the supertwins are tuned to the hilt, sportbikes have been developed under Balance of Performance (BoP) rules, which are designed to equalize the speed and capabilities of competing motorbikes, which were not necessarily evenly matched out of the showroom. It’s the same principle that’s applied to the Next Generation Supersport class, which sees 600cc fours compete alongside 765cc to 900cc triples and near 1000cc twins.
In order to give these bikes parity on the race track, organisers control various regulations like rev limits, minimum weights, torque mapping, throttle openings and engine tuning concessions. It means that a Triumph, which comes out of the showroom with 95bhp, must run to a strict rev limit and reduced power. It also has a minimum wet weight of 165kg, while an Aprilia or Yamaha twin running under sportbike regs can be up to 7kg lighter.
This year’s split Sportbike TT regulations mean Aprilia and Yamaha runners can enter under either supertwin or sportbike rules. The difference will be staggering, with a fully tuned supertwin a good 15-20bhp more powerful and 8kg lighter than a visually similar sportbike – and they’re allowed chassis upgrades too. A supertwin is allowed to run a race gearbox, racing wheels, custom fairings, different forks and upgraded brakes, where the sportbike must make do with homologated parts based on the production machine. All those modifications come at a cost however, both financially and in terms of machine durability.
Unsurprisingly the top 10 qualifiers for this year’s Sportbike TTs are all running to the old supertwin regulations. The top sportbike runner is 11th placed Dominic Herbertson, who posted a best of 118.589mph on his factory backed Triumph. The 31-year-old lumberjack knows only too well how the different machines compare, having ridden a Paton to a podium finish in last year’s second Supertwin TT.
He told us: “The Paton I was on last year was around 105 to 107bhp, and then there are the Aprilias which are banging out around 113-114bhp. We’re running to the same rules as the world and British (Sportbike) championship, which means we’re limited to 90bhp and restricted to the fairings we use. Even the engine mounts (on the Triumph) have to be standard. The idea is to make it more affordable.
“The most exciting thing about supertwin racing is that it's old engineering. What I mean by that is that they are tuned to an inch of their life, and the thing about tuning a bike is it may go fast but it could break down at any second around here. It can be exciting for the spectators but, because this bike is restricted, we’re getting a lot more out of the stock engine and it proved reliable at the North West 200, where it spent a lot of time on the red line.
“The way they’ve made it more affordable is by keeping the rules really tight. We have to run standardized electronics. The Triumph has been very successful on the short circuits but bringing it to the Isle of Man is uncharted territory. On the twin, I knew exactly where my braking markers were and I knew exactly where to get on the throttle. Because it’s a triple rather than a twin, the characteristics are totally different and the gearing’s totally different. As a result, I’m having to learn again, as all the braking markers have changed, but we’re getting faster every time we go out. This year we’ve brought a knife to a gunfight but next year, when it all goes sportbike, we are going to be ahead of the curve.”
The new rules will not only make it cheaper for competitors, they should also bring a more diverse grid that better reflects the bikes that are on sale today. Chinese brand CF Moto is entering a two-rider team at this year’s TT, running Jamie Cringle and Shaun Anderson on their three-cylinder 675SR-R under sportbike regulations. Other homologated bikes allowed under the rules include the four-cylinder Kawasaki ZX-4RR and Kove 450RR Pro, as well as the Suzuki GSX-8R which won last year’s National Sportbike Championship on the short circuits, and we expect to see many of those gridding up at TT 2027.
But for now we’re looking forward to two corking Carole Nash Sportbike TTs. Will Michael Dunlop say farewell to his beloved Paton with two more wins? Can Peter Hickman’s trick R7 finally best its nemesis in its fourth year of competition, or will a new name find its way on the famous trophy?
Photos: Isle of Man TT Races/Impact Images
