ADVICE ON HORSEBOX & TRAILER TYRESHorseboxes and Trailers tend to be heavily constructed, used intermittently, and stored in the open. Hence, though the mileage covered might be very limited, the tyres can be liable to cause more than their fair share of problems. The following are some points that need special attention.Tyre specification: Make sure that the tyres fitted are of the correct load rating for the trailer. The trailer should have a chassis plate with the maximum laden weight – if not, check with the manufacturer or weigh the trailer at a weighbridge, allowing for the load and equipment normally carried. Check with a tyre dealer that the tyres fitted are marked with an adequate load rating and/or load index, and that you know the correct tyre pressures. Tyre Condition:Tread wear should be checked – the legal requirement is that there must be at least 1.6mm of tread depth across the central three-quarters of the tread width, all the way round the tyre circumference. When checking a tyre, look for fine surface cracks in the rubber, around the base of the tread grooves or on the side-walls. Such cracking can accumulate over a period of years, particularly if the tyre is exposed to sunlight, and indicates that the tyre should be renewed.Check all the way round the tread for cuts or other damage, and look on the inner as well as the outer side-walls – they may need a hose down to do this properly. Look for wear or damage caused by contact with the bodywork or mudguards. Look closely at the rubber tyre valve stem for cracks, and make sure that valve caps are fitted.Tyre Maintenance:Check the tyre pressures while they are cold, and correct as required – get any significant loss of air checked and repaired. If the trailer is to be left any length of time – say more than few weeks, cover the tyres loosely to shade them from sunlight – and put a note on the hitch as a reminder. If a long period of disuse is expected, it will be worth putting blocks under the axles to take the weight off the tyres, as well as shading them with sackcloth or a similar permeable material.Check the wheel nuts for tightness by undoing them a turn, then re-tightening to the correct setting. When fitting a wheel, a little oil can be applied to the threads of the stud, but not to the nut seating. Make sure that the brakes work properly, and that they free off correctly when not applied.