Alas, we have discovered two more tires with ominous bulges on our BH3670RL (2008 model). This unit has very few miles and is stored inside all winter. We have already replaced one of these tires six months ago, but had great difficulty finding tires rated for the weight and size of the trailer. What does the factory recommend that would be available in Western Canada? We plan to buy four tires this time, and will continue to use the recently purchased one as the spare.