Are Trailer Wheel Hub Bore (Pilot Diameter) Measurements Universal Sizes

Question:

Replacing 4.8x 8 wheels and tires with 12” ones. Tires on a cox trailer, boat and motor weight 920 lbs. Presently there are buddy bearings on the hubs.Bolt pattern 4 x 4”. Question: is center hub opening universal size ?

asked by: Mike G

Expert Reply:

The center hub bore size can vary between wheels so you will need to verify the hub bore size (pilot diameter) before replacing your 8" wheels with 12" wheels. For example, the Steel Spoke Trailer Wheel # AM20124 with the galvanized finish has the 4 on 4" bolt pattern that it looks like you have and a pilot diameter of 2.84".

It looks like your current lug nuts sit flush against your wheel and they don't have a cone shape. If this is the case then you will need 60 degree coned lug nuts like part # N10R.

Also be sure to take into account your larger and wider tire size with the 12" wheels. Make sure that you have enough clearance height-wise and width-wise. For example, the Kenda 4.80-12 Bias Trailer Tire with 12" Galvanized Wheel # AM30630 has a section width of 4.9" and an outer diameter of 20.7".

expert reply by: Jon G