How Mercedes F1 is trying to claw back its lost downforce

These changes to the aero rules appear to have hit the low rake runners the most, but you could also argue that those teams have also made the biggest effort to recover their losses too.

So, let’s take a look at what Mercedes has done in response to the challenges thrown at it, and why it might be suffering more than its counterparts.

Aggressive floor

When Mercedes finally revealed the new floor of its W12 during pre-season testing it appeared it had some of the most mature solutions on the grid. Here are the details.

Mercedes AMG F1 W12 floor

Photo by: Giorgio Piola

Teams have rolled up the edge of the floor in this region for some time now. But, in order that some of the airflow from the upper and lower side of the floor converge at different rates, Mercedes has added a series of ever decreasing wave sections for this year. This should help to mitigate some of the losses associated with the regulation changes that prevent the use of slots and fully enclosed holes in the floor.
Whilst the regulations call for the floor to taper back toward the rear tyre, Mercedes, like a number of teams, has opted to give up some of the available floor space and create an additional cutout. This creates a Z-shaped cutout whereby a section of the floor is returned to a parallel edge before tapering again ahead of the tyre. In Mercedes' case, the parallel section is quite short, if compared with the likes of Red Bull, for example.
Ahead of the rear tyre, Mercedes has a number of solutions, including a collection of outwardly angled fins that have been boxed in to try and enforce an aerodynamic effect. They have three strakes of varying shapes and lengths inboard of this which look to direct the flow between the edge of the diffuser and side of the tyre. Then, quite differently to everyone else on the grid, its floor is angled upward towards the trailing edge, where a Gurney flap has been applied to the underside of the floor.
Mercedes has gone to considerable effort to enlarge the size of this flow pathway into the coke bottle region, with the shape of the sidepods altered to raise the cooling outlet. Meanwhile, it has also reworked the shape of the floor in order that the floor descends beneath the gearbox and crash structure, further opening up space for the air to flow into.

Even with these extensive changes, it’s clear to see that the W12 wasn’t as stable as the drivers would like under certain conditions, meaning it still has plenty to work to do over the remainder of the season.

And, with Mercedes seeming to have worked harder than some of its competitors on recovering losses with the design details of its floor, you have to look at the impact of some of the other 2021 regulation changes to try to understand where it is losing out.

The winglets mounted to the lower half of the brake duct fence are 40mm narrower in 2021. This might not seem like a big deal, as everyone suffers the same fate, but there’s a difference as to where those winglets line up relative to the floor ahead, depending on the rake angle of the car.

As such, both groups would have used them differently, and it appears their narrowing has impeded some of the work they did for the low rake runners.

Furthermore, the strakes in the diffuser have also been cut down by 50mm, which would logically harm the high rake runners if not for them already accounting for a loss here relative to their counterparts.

However, for the low rake runners, their diffusers had been designed to operate with the benefit of those strakes being closer to the ground and the effect that proximity has. With this benefit now removed, their diffuser will likely be less effective.

Red Bull plays catch up…

The RB16B features a new rear suspension layout for 2021 that draws its inspiration from the arrangement used by Mercedes last season.

Red Bull Racing RB16B comparison rear suspension

In both cases the primary reason behind the implementation is aerodynamic, as the teams look to position each of the suspension elements in more favourable positions.

Red Bull hasn’t been able to fully appropriate the Mercedes design, as that would have required more tokens than it had at its disposal. But it has still been able to make changes that will undoubtedly improve flow over the rear of the car.

The track rod position is the major difference for Red Bull (highlighted in blue). It has moved this to the front of its assembly and effectively flipped the wishbone over so that it can mount the rear leg as high and rearward as is possible.

Of course, it cannot be underestimated how much of a structural challenge this is. Whilst the optimum aerodynamic positions might give you extra performance, it’s only worthwhile if you’re not adding a substantial amount of weight to the car that would offset any gains.