In regards to my letter on the subject of precession as a cause of wheel loss [routeone/Letters/9 January].
Unfortunately, my explanation that a simple cure for this problem exists [was cut].
Until quite recently, commercial vehicles, and many quality cars, employed left-hand thread wheel nuts on the left side of the vehicle.
This was in order to counter the effects of precession, which causes the nuts to try to rotate in the same direction as the wheel.
For some inexplicable reason, a few decades ago we adopted the European system of using right-hand threads all round, with the predictable result that left-hand wheels started falling off with monotonous regularity.
The authorities' response was to give it a name – 'wheel-loss syndrome' – and to advise checking the wheel nuts every five minutes.
There is no 'syndrome' – it is the entirely predictable effect of precession.
If we were to revert to the tried and tested system of using left-hand threads on left-side wheels, the problem would disappear as quickly as it arose.
Do the authorities not understand this?
Hugo Miller, Arun coaches
