In an effort to repair the handling woes of the W01, Mercedes boss Ross Brawn has indicated that the team will lengthen the car’s wheelbase. It’s been reported that the team has been unable to cure the car’s fundamental imbalance, which is causing understeer. This seems to have affected comeback kid Michael Schumacher more than it has his team mate Nico Rosberg, but irrespective of that, the car has been generally lagging behind the pace of the Ferraris, Red Bulls and McLarens.
Brawn recently told Autosport, “The problem is not actually the wheelbase per se, it is the weight distribution. We got the weight distribution wrong. When we got to test these tyres we realied we didn’t have the correct weight distribution and we went to the limit with what we could achieve with this car. It is not the wheelbase as such, it is the weight distribution that is not what we wanted it.”
In other words, altering the wheelbase is only a work-around, not a real solution. An ideal fix would be to revise the chassis design, but under current regulations the monocoque is homologated at the beginning of the season, and can’t be changed. See the relevant FIA technical regulation, below.
a) One specification of each of the following parts must be homologated prior to the first Event of the Championship season :
– survival cell ;
– principal and second roll structures ;
– front, rear and side impact structures ;
– front wheel ;
– rear wheel.
Once homologated, changes to the these parts will only be permitted for clear safety or reliability reasons following written approval from the FIA.
As is the case with many of the current technical and sporting regs, the homologation rules were introduced to impose curbs on spending. Once the elements listed above have been homologated with the FIA, they’re set in stone, more or less, and aren’t subject to continuous upgrades. While this might help limit budget allocation, it also means that if the chassis is fundamentally wrong it can’t be fixed. This is the problem Mercedes is facing.
Moreover, the chassis problem is partly the result of another regulatory restriction, namely, limited on-track testing. In-season testing is banned entirely, and pre-season testing is limited to a relatively brief window in February, with only four sanctioned test sessions.
This season saw two key changes to the technical regs, i.e. larger fuel tanks and smaller front wheels, which in turn had an impact on the weight distribution needs for the tires.
“The tyres changed quite a bit,” Brawn said, “and we didn’t have the opportunity to test these tyres, and we didn’t have as good a guess of what was required as some of the other teams. So we will have a modification to the car at Barcelona which will give us a better range for the weight distribution that we can achieve.”