Small Boat Ownership - Trailer Tyres
After reversing the boat onto the driveway after one particular trip recently, as we were un-loading, we could clearly hear a loud hissing noise coming from one of the wheels. Shortly afterwards, the tyre was flat. On inspection we noticed that some of the strengthening wires in the wall of the tyre were protruding, one of which presumably had punctured the tyre. Thinking we had perhaps side scraped a kerb somewhere, or had chafed it along sharp rocks on the beach, we had it changed and thought no more about it.
A couple of months later, a far more serious tyre situation occurred. Driving at 60 mph on a long straight stretch of road, one of the trailer types quite literally exploded. Fortunately, this didn’t have much effect on the true running of the trailer itself, and we were able to pull off the road safely where we found that the entire tyre wall had split. So on went the spare. But being a good way from home, we decided to find a tyre place in case sods law handed out another dose of the same on the way home.
When the chap in the tyre centre saw the split tyre he said it was no wonder it had blown. It was completely the wrong type of tyre for the job, and the problem with its predecessor with the protruding wires was probably down to the same reason. Both tyres had been fitted from new and had hardly any wear on them, but for a number of reasons they were simply not up to the job, We had been ‘lucky’ in both instances that no other damage resulted say through loss of control. Not all trailer blow outs end quite so quietly.
The tyres in question were 4-ply car tyres. Boating outfits these days seem to be getting heavier and heavier to the point where some may even be heavier than the car that is towing them. Car tyres are designed to support that sort of weight. However, cars have their weight spread over four wheels whereas boats have it coming down through just two, with all of it concentrated at any given point in time on one small area of contact with the road. Bouncing along the road as trailers tend to do when the surface is anything other than mirror flat, it was only a matter of time before the walls gave way under the strain.
The chap in the typre place suggested we had an 8-ply tyre fitted, though a 6-ply would possibly have done the job. These higher ply rated tyres have additional wall strength built in to them with trailing in mind. But it isn’t only ply ratings and wall strength that can let you down as we were to find out. I didn’t know this until it was pointed out to me, but tyres have a date of manufacture moulded onto their side wall. On cars, tyres are not expected to last long enough for the rubber to deteriorate. But on boats it’s a different matter. They can have a good legal tread on them throughout the entire life of the trailer.
Sunlight, so I am told, causes rubber to perish. Having a vehicle standing for a long time without its wheels moving also causes damage. Long periods of standing in-activity are a regular feature of boat trailers. Yes I know that the man in the tyre centre is in the business of selling tyres, so you would expect him to say this, but I am assured that tyres ought to be changed at least every four years regardless of tread, if they are to be reliable. It’s not so bad if you are pottering around locally, so long as you have a spare. It’s those long journeys and trailing on fast roads where the cost of putting the right tyres on and keeping within their 'best before' dates can suddenly become a good investment.