TT Supertwins: predicting the unpredictable
Take your pick from this lot!
Supertwins are one of the most intriguing classes at the Isle of Man TT Races. The little bikes are big on heart and big on drama, and it is hard to predict who will emerge victorious in the two three-lap TTs taking place this year.
Last year saw the TT’s big two, Michael Dunlop and Peter Hickman, share the race wins and they go into the races having topped the times in qualifying. All things being equal, you’d fully expect them to be taking the honours again this time around… although Supertwin racing rarely goes according to plan.
It’s a class where testing time is often limited and the highly tuned engines stressed to the max. As a result, it’s a race which always throws up surprise results. The bikes are hammered for almost a full hour as they take on over 110 miles of racing at full throttle. It means reliability plays as important part as outright speed.
As the name suggests, Supertwins are two-cylinder machines. Most bikes start life as quite humble production machines but are very heavily modified. Until recently the class had an engine capacity limit of 650cc, meaning it was dominated by Kawasaki powered bikes, but two years ago the capacity limit was upped to 700cc and the class renamed ‘Supertwin’.
This allows bikes like the Aprilia RS 660 and Yamaha R7 to enter too, better reflecting the motorcycles on sale today. To be eligible, manufacturers have to build 30 road bikes as a base. This means that Italian company Paton can enter with its limited run S1-R, although more on that later!
Supertwins can weigh 150kg and rev to 11,000rpm, with the most powerful bikes producing around 100bhp. Considering a standard Kawasaki Z650 makes less than 70bhp when it leaves the showroom, the bikes are very heavily tuned.
Compared to the other classes at the Isle of Man TT, the Supertwins are arguably the most interesting from a technical perspective.
To make up for their lesser capacity, the 650s have more freedom to tune the fuel injection system, while the Aprilia and Yamaha must use the standard throttle bodies – albeit with some permitted modifications.
But the freedom of rules makes this one heck of a class for the engineers. We won’t bore you with all the things you can do to the engine but, with a few limitations, you can change and tune internals to your heart’s content. You can also swap the wheels, brakes and suspension for racing items and, what’s particularly interesting, you can also change the bodywork for better aerodynamics.
Combined with the boom of the two cylinder engines, it makes for a race full of bikes that have a different look and sound to any other solos found at the TT. Supertwins may have half the power of the 1000cc machines, but their high corner speeds mean lap times average in excess of 120mph – around 10mph less than the Superbikes.
Who’s who and what’s what?
There are two Supertwin TTs in 2024: the Metzeler Supertwin TT is scheduled for Tuesday June 4, and the Entire Cover Insurance Supertwin TT closes action on Friday June 7 (although the schedule is all weather dependent).
Fastest in qualifying is Michael Dunlop, who recorded a 121.882mph lap on his Paton S1-R. He won the first Supertwin TT on that bike last year, but broke down in the second. The retro looking Italian machine, which is built in limited numbers, is powered by a highly tuned Kawasaki 650 engine. If the bike holds together, he’ll be favourite for both races.
Peter Hickman won the second outing on his Yamaha R7. The 2023 TT probably came too early for the Yamaha runners. It was the first year of the R7 and the special tuning parts were late in arriving. That said, for all the bike couldn’t match the Patons for speed, it was reliable and Hicky won after a number of rivals dropped out.
He prepares the bikes out of his own PHR Performance workshops in Lincolnshire and the Supertwin entry runs in distinctive yellow Swan livery. They’ve found a lot of speed from the R7 in the past 12 months, and although Hicky’s physique is better suited to the bigger bikes, he’s formidable on anything he races.
Third in practice was Jamie Coward, riding a Kawasaki for his KTS Racing team. His two previous TT podiums have come in the class (second in the 2019 Lightweight and third in the first Supertwin last year). He’s having a good TT and should be a contender again this time around, having clocked over 120mph in practice.
Also over 120mph is popular Geordie Dominic Herbertson, who is mounted on the favoured Paton this year. He was one of many retirements last year, missing out on a podium after a late breakdown. He’s unlikely to have a better shot at standing on the box at TT’24.
Fifth in qualifying is one of the star names of TT’24. Davey Todd has been on the podium in both the Superbike and Supersport TTs and will lead the experienced Dafabet Kawasaki team’s charge. Their Z650 based racer won the Lightweight TT three times and took Josh Brookes to a debut podium in the ‘twins last year. Todd hasn’t done too many laps on the Supertwin in practice, so we reckon there’s plenty more to come in the races.
Top Aprilia is Mike Browne, sixth in qualifying. The Irishman is a specialist on the small bikes and broke down while leading the second race last year. He’s one of many podium contenders, a list which includes the VAS Engine Paton pairing of Italian rider Stefano Bonetti and Pierre-Yves Bian, the Frenchman who finished second last year.
There are also a number of big names mounted on Yamahas, including the aforementioned Josh Brookes, Michael Rutter and Paul Jordan, who will lead the pack away from number one. With the exception of Hickman, the Yamahas haven’t quite found the speed of the Patons, however the R7 is proving reliable and able to take advantage of any slip ups from their rivals.
Choosing a winner out of this lot is pretty tricky but thankfully we won’t have to wait too long to find out who our victors will be.
