All of our standard racks (5, 6, and 7) have 10 inch spacing between each tire basket. The 3X and 5X have 15 inch spacing between tire baskets and the 412 has 12 inch spacing. The 5X is much wider than the regular 5 rack. Specific rack specs are found on each product page. See a video here for the differences between the 5 and 5X.