You can never tell with F1 if a decision is media/sponsorship driven or safety driven. But they all have the same tyres and so I guess it doesn't matter about the weight ... and unsprung weight is less critical in cars than motorbikes.
A great question. Baffles me why many manufacturers offer light weight wheels, at a high premium, then have tyre pressure sensors and any old tyre. As per my post elsewhere (re: tyre pressure quages) 33 grammes of unwanted weight. Been looking at a replacement for my GS. Alsorts of adv bikes, XR, 1250 GS, Multi (yes 1260 ...) and similar. The difference in weight between PPeak 1260s and Multi enduro and others is an eye opener. So yes, why not tyres too when being serious about handling and weight? Had a test ride on the new XR. In the ‘extras’ list (BMW!) they have lighweight wheels. They come with racing discs...which are thicker and weigh more. BUT when a BM designer was asked he agreed that weight was taken away, then added. (Eh?) He e xplained that rotating mass was reduced as it was more centralised. Which made some sense and still had potential gains for handling.
If we can all just agree to weigh our preffered tyres before the next set are fitted...easy database to assemble. Grant
That is assuming that people give a toss. Personally, I don't. I can save weight for free by just going on a diet!!!!
I remember many years ago when people were swapping their Brembo 916 etc wheels for the later Marcheseni wheels "because they were lighter", it was pointed out that the mass difference between the bare wheels was less than the variation in mass of many popular tyre makes at the time.
It's an impossible situation. I would rather have a heavier tyre that lasts and does not explode. And when they add balancing weights to my wheel, I don't question it, but some may. Others might prefer to save unsprung weight by having a lighter tyre that lasts 10 seconds or blows out if you run over a stone. I want to ride on the roads around me with their frequent pot-holes, rocks delivered by tractors, or bits of scrap metal from the docks (who export scrap to Spain) and not get punctures (or worse) every 10 seconds. Race tracks are very different and a race tyre can be less robust. Castle Combe has agricultural farming on the infield, but I assume that farm vehicles can only get across the track in one place and the track is swept where they cross. I hope!
When it came to the single make tyre rule, that was cost driven from the FIA, who in turn probably had a big old bung from the tyre manufacturer to be the brand of choice. Michelin were the choice of the top teams (apart from Ferrari) as they would go balls deep into the development with you - we used to have different compounds for different circuits and driver and weather conditions. they even gave us wind tunnel tyres to mirror the fullscale test cars' options for when we needed to do circuit optimisation aero packages. The smaller teams couldn't compete with that, so the decision was made to have a single tyre and a limit the options. Even in racecars the unsprung weight is of paramount importance. the same thing that goes for bikes goes for cars, especially at that level, and it means that your wishbones and trackrods become more effective due to not having to deal with the massive pendulum on the end, so in turn you could make them lighter if you needed to. The other thing it allows you to do is keep the package kerb weight down which is important - you ideally wanted your car to be sub minimum weight, because then you could put ballast weights in to balance the thing how you saw fit.
