Having endured a blowout on my previous RV, a motorhome I'm gun shy about letting tires go too long. To each his own but, after 5 or 6 years I'm buying a new set of tires. I have the EZ lube axles so I just do that. They are far better than the old days when you had to pull everything apart to "pack" your bearings. Adjusting the brakes is super easy and I do that once a year. It never needs much adjusting. The roof is what I pay the most attention to. Our first travel trailer was in 1991. Personally, I've never had a bearing or axle issue and never known anyone too. However, I'm certain that the bearings can fail if neglected or, have a manufacturer defect, or get water in them and rust up.