Search new + high quality used tires online. Size 235 50 R21 starting at: $33.74. Tires in stock: 72. Available brands: 3 with 4 models. All season: 70. Winter: 1. Summer: 1.. Selling all used tires at discount costs. All used tires go through 2 layers of inspection on specialized equipment. One year warranty + free shipping on all inventory ;) Happy shopping!