Wheel nuts are one of the most crucial parts on a Formula 1 car. They determain how fast a pitstop is and keep all four wheels tied to the chassis, even when under five times their gravitational weight. The Wheel Nut clamps the tyre to the axel by connecting two sets of pins and threads unique to each wheel [below] which are designed to take the high literal loads that try to loosen them. In theory, even if the wheel nut comes loose the tyre should not fall off, but it sometimes does.
What do we mean when we say cross-threaded? Think of the inside of a wheel nut as a vinyl record, a cross-threaded wheelnut means that the walls on the threads get broken; this normally happens when putting the wheel nut on under high presure. We saw this in Bahrain when Lewis Hamilton’s mechanic did exactly that which then setup the problem in the next stop, which was a wheel nut that wouldn’t come off, costing Lewis valuable and possible race winning time.
However, some teams have come up with a solution to stop this from happening. Taken from DTM and other touring car racing, the nut-in-wheel is a solution Mercedes first introduced last year. Unlike the normal ‘loose’ wheel nut, the wheel nut is actually apart of the alloy, which means the mechanics don’t have to take anything off when changing tyres, its just a case of changing wheel. It is an ingenious solution that ends up in teams making 2 second to 3 second pitstops on average a race. The only downside to the system is that you still get the problem of cross-threading, and if you cross-thread these wheel nuts, that means the whole set of tyres needs to be changed as the rules say you must use the set of tyres allocated and not ones from other sets; costing you even more valuable seconds.
Teams try to seek out a much time as possible for pitstops. But every second gained is more time lost when somthing goes wrong.