ANALYSIS: how did differing tyre combinations impacted WorldSBK at Assen?

Monday, 26 July 2021 09:53 GMT

Always a hot topic and in conversation more than ever, tyres were once again on everyone’s lips for Round 5

Following the explosive fifth round of the 2021 MOTUL FIM Superbike World Championship at the TT Circuit Assen for the Prosecco DOC Dutch Round, one topic once again surged into the spotlight: tyres. Pirelli – the Official Sole Tyre Supplier to the WorldSBK paddock – unveiled new solutions for Assen with a new front tyre, the A0721. As well as this, the A0508 development tyre from Misano also returned, meaning that the options were vast for front end feel come the races.

THE NUMBERS: who used which compound?

The new A0721 is a softer tyre, as it the A0508; both were good front options for the weekend and plenty of riders gambled on them. In Race 2, all of the riders were on a development tyre of some sort, with 17 going for the new A0721. However, on the rear, it was less decisive as most riders went with the returning A0557 SCX tyre back from Misano and the standard, harder SC1 proving just as popular. 11 riders opted for the development SCX whist the remaining eight went for the SC0.

That was a stark contrast to the much brighter conditions of Saturday, when nine riders went for the new development front, seven went with the established SC1 and the remaining four went to the returning development SC1. On the rear, 11 riders went for the SCX development option, nine on the SC0 and one other on the SCX standard.

WINNING COMBINATION: how Rea made it work perfectly

Now we have the numbers of the two main races, there’s one man who got it absolutely nailed: Jonathan Rea (Kawasaki Racing Team WorldSBK). Rea took victory in Race 1 with the new front tyre and with the development SCX, also using this combination to give him the Tissot Superpole Race win. However, in Race 2, he didn’t stick to what he knew; he continued with the new SC1 at the front but switched to the SC0 standard option. This would pay dividends as Rea got the win. Race 1 and the Tissot Superpole Race were both run on a track temperature of 37 degrees Celsius at the start of the race, whilst when lights went out for Race 2, it had dropped to 32 degrees Celsius. A five degrees difference, perhaps an important one if Jonathan Rea’s media debriefs were anything to go by.

Speaking on Saturday, Rea commented, shedding light on his decision in Race 1 and also hailing the work of crew chief Pere Riba: “I’ve used every slick rear tyre available to me this year. The SCX, the SCX evolution and also the SC0. I was listening to what Scott was saying and it is true that different circuits and different temperatures can have different requests for the bike and the tyre and that’s the biggest influence of the race. I did a long run on Friday on the new front and felt quite comfortable. Pere made a plan; Pirelli brought a new front tyre and we ended up with the only bike in Race 1 Parc Ferme with that and it’s a good feeling when you see that you do your homework, and it pays off. Sometimes, you come away with egg on your face, but we pulled it off; the decision was clear-cut.”

So, why the change on Sunday afternoon for Race 2? Rea explained that it was weather-influenced: “We changed the tyre due to the overnight rain and the temperature was about 3-4 degrees lower, which we figured could be the crossover point between using the development SCX tyre of the SC0. It is nice to win in Race 1 with the soft and then on Sunday with the standard tyre and it is a huge testament to the guys in the box. We made quite a big chassis set-up change with the geometry of the bike, wheelbase and it seems much easier to ride. I could put the bike where I wanted, it was nimble and stable in the fast sections, something I think we’ll need at Most.”

OUTFOXING THE OPPOSITION: Redding’s tyre struggles prevent him from Rea battle

Whilst Rea was clear out ahead, it was Scott Redding ( Racing – Ducati) who opted for different combinations to Rea, ultimately seeing him finish second to him in Race 1 and Race 2. After Race 1, Redding commented on the performance drop: “I felt like I had the pace in Race 1 and I got ahead of Toprak, but then he started fighting with me, which let Jonny escape. I started struggling with the front tyre on the right side, I think he did too as I could feel him slowing up. I dropped the hammer after I passed Toprak but that just ended the tyre as it couldn’t sustain it. The front was closing more, and amore and it was about survival and trying to keep Toprak at bay.”

Then for Race 2, Redding changed from the standard SC1 front to the development SC1 front, but still had to preserve it in the early stages of the race: “I struggled in the beginning to pass other riders as I didn’t want to push the front tyre too much. Those guys got away and there was nothing I could do, until the front tyre came to me, and I could start putting in the pace. I had to be a bit clever, but the tyres are a big part of the decisions but as usual, we found the set-up for the race in the last race.”

CONCLUSIVELY: what can we take from this?

Tyres are always a major talking point but in 2021, the topic of conversation surrounding the development of the rubber in WorldSBK has been everywhere. Whether it is from the intermediate tyre debate back at Aragon and again at Donington Park or the innovations and solutions from Pirelli at Misano and again at Assen, so many options to choose from is creating a new dynamic before the racing starts.

You can see the tyres sheet from Race 1 here, the Tissot Superpole Race here and Race 2 here.

Keep up with all of the drama in World Superbike in 2021 with the WorldSBK VideoPass!