Meet the Supertwins

You’ve seen the snazzy racers from the Entire Cover Supertwin TT, but have you seen the road going versions they start out as? Here’s a look at the road going twins which are quite frankly marvellous…

We might be biased but we think the TT supertwins are among the most impressive machines you’ll see in the Isle of Man TT race paddock.

They might be the least powerful bikes (making around 100bhp) but these once humble motorbikes are highly modified, with engines tuned to make almost 50% more power than stock, while the chassis are comprehensively reworked with strengthened frames, lighter wheels, upgraded brakes and suspension – the result being motorcycles which can lap the legendary TT course at an average of over 120mph (in the right hands of course).

But all Supertwins must start out as motorcycles we can all buy from a dealership so, if you’re as taken by the twins as we are, here are the four fabulous flyers which will be fighting for honours in the first week of June.

Aprilia RS 660

On paper the Aprilia is the bike to have for Supertwin racing. With 100bhp out of the crate, not to mention a trick chassis and class leading electronics, the Aprilia is the benchmark lightweight sports bike.

The parallel twin engine is essentially constructed from one bank of cylinders from an RSV4 superbike, while the chassis is also a real work of art, being an aluminium double beam type frame. It’s always been a trick little machine but, for 2025, it’s been further updated. The new bodywork incorporates MotoGP style aerodynamic wings on the fairing which not only look cool, but are said to improve handling as well.

As a performance road bike, the RS 660 is the pick of the mainstream offerings – even though no-one’s really taken the TT by the scruff of the neck with one. 

Kawasaki Z650/Ninja 650

Two entries for the price of one from Kawasaki, who will sell you a naked (Z650) or faired (Ninja 650) version of their Supertwin contender.

The quick Kwakker is arguably the bike which helped establish the class over a decade ago. It took over from the Suzuki SV650 as the lightweight club racer of choice and provided the basis for a new generation of road racing machines.

As the oldest design in the Supertwin pack the Kawasaki lacks behind a little in terms of road bike performance, but it is a very tunable package. Kawasaki racers are very heavily modified and, because they have a smaller capacity engine than the Aprilia and Yamaha, they are allowed bigger throttle bodies on the race bikes. That makes them very competitive and means the Kawasaki is still the most common machine found in Supertwin racing today.

Paton S1-R

Paton was an Italian maker of Grand Prix race bikes. They first raced in the late ‘50s and were around until the end of the 500cc Grand Prix championship in 2001. Today’s Paton company still competes at the TT, focussing solely on the Supertwins with its S1R.

The S1-R is an outlier among the Supertwins as it’s not a mass market machine. It’s an exotic sportsbike which is made in small numbers. The styling reflects Patons from the 1960s, and it even has traditional twin shock absorbers. At its heart is a modified Kawasaki 650 engine and it has been a very successful package.

Paton has won all but one Supertwin/Lightweight TT since 2017, and that defeat only came when a couple of the Italian machines broke down and handed Peter Hickman victory on his Yamaha.

They’re beautiful things, though at £42,000 for a road going version it costs around six times as much as a stock Kawasaki Z650!

Yamaha MT-07/R7

Yamaha is another manufacturer with a dual entry, in the form of the naked MT-07 and faired R7.

Because the liberal Supertwin rules allow for the stock fairing to be replaced by a slippery race item, many TT teams chose the MT-07 as their base, although both bikes are essentially the same mechanically.

Although the Yamaha’s 689cc engine is bigger than 650 found in the Kawasakis and Patons, they have to run standard throttle bodies and this means that they’re still not yet as powerful as the other bikes on the grid.

Peter Hickman won one Supertwin TT in 2023 on his R7, albeit after several Patons broke down in front of him, but that was the bike’s debut year at the TT and it is getting quicker and quicker each year.

As standard, the R7 is an affordable street bike with a relatively basic specification. The engine produces 73bhp in stock trim, while the steel frame is far less sophisticated than the superbike style unit found on the Aprilia.

It’s got some race pedigree though. The R7 is used in the Women’s World Championship and in National Sportbike racing in the UK, where it competes against the Aprilia, Kawasaki and Triumph’s Daytona 660. This race experience means the number of special parts and racing knowledge is increasing, making the TT racer more and more competitive each year.

The organisers are constantly looking at the rules of the Supertwin TT to ensure parity between all the different brands and their slightly different engine capacities. While history suggests the Paton mounted riders will start as favourites for the two 2025 Supertwin TTs, there’s no reason why we can’t see an Aprilia, Kawasaki or Yamaha atop the podium come the first week in June.