TECH TUESDAY: The tiny design modify that made all the distinction for Mercedes in Sochi

Mercedes’ victory in Sochi might have carried some debate since of the notorious ‘switch’ in between Lewis Hamilton and Valtteri Bottas. It was nothing less than definite– and part of the factor for that important benefit over the Ferrari group was a little information hidden within its rear wheels.

The Sochi track is rather extreme in one specific need: just how much tyre energy can be taken early in a certifying lap so regarding still have the backs alive in the last sector, which comprises lots of right-angle bends and low-speed velocity zones.

The smooth surface integrated with the design makes the tire preparation to satisfy this challenge a very detailed process. The surface area’s absence of abrasion makes it hard to generate heat in the front tyres, demanding a longer than normal preparation. The longer the front takes to provide good grip, the more pressure is put onto the rears as the vehicle is unbalanced. Anything for that reason which can dissipate heat away from the rear tires is better than ever around this track, as it opens out the narrow window of balancing the temperature in between front and rear tyres. In this regard, Mercedes’ recently-introduced concave rear brake drum, in mix with the unique rear wheel rim design (presented at Medical spa), was an effective property– and rather potentially a vital part of the reason for Merc’s considerable qualifying benefit over Ferrari.

Getting heat into the tyres is about balancing the temperature of the tyre’s surface area with that of its core. If the central, core, part of the tyre stays cool the tyre will be relatively inelastic. The tyre requires to flex under load to develop the opposing force and it can refrain from doing this really effectively when the core is cool. It is fairly simple to generate heat on the tyre’s surface just by moving the tire across the track, however that will not construct up the lateral loads that induce heat into the core. Unless genuine care is taken, you can quickly wind up with an overheated surface however a cold core– and this can end up being a self-magnifying loop.

So the lateral loads have to be massaged into the tyre, gradually developing up the core’s temperature level while not overheating its surface. Preferably, the core and the surface then reach the optimum temperature concurrently. The smoother the track surface area, the longer this procedure takes as the tire’s tread has less to ‘bite’ into. Since the rear tyres are on the driven wheels, it’s reasonably simple to create heat in them.

In fact the problem is generally in keeping the temperature levels from getting too high. The longer the process of bringing the fronts up to temperature level takes, the longer the backs are carrying a higher proportion of the load. At Sochi, the rears can already be verging on too hot at the beginning of the flying lap, simply as the fronts have actually finally come up to temperature level. The closer to that threshold the rear tyres are, the less the chauffeur can manage to utilize them hard in the very first sector– because the last sector is extremely demanding of the backs, particularly in traction.

At Sochi, the Mercedes fixed this dilemma much better than the Ferrari– which might be fast in either Sector 1 or Sector 3, but not both. In 2015 it was Mercedes which was in trouble with this conflict. However not this time.

The rear wheel rim style Mercedes presented at Spa includes numerous ridges around its area. These not only allow the heat to dissipate over a higher area, however their style creates a fan impact as the wheel turns, drawing much more heat far from the wheel rim and avoiding it, for that reason, from entering the tyre. The concave design of the carbon fibre aero-drum around the disc presented at Singapore builds on this by producing an atmospheric pressure difference there that causes the hot air to be extracted even faster.

These little details in parts of the car not aesthetically obvious probably made the vital difference in Sochi.