The MGB left Abingdon on steel wheels as standard equipment throughout its production run, either 4 to 5-inch disc wheels with a separate polished hub cap on early cars, or Rostyle wheels from September 1969 to 1980. Alloy wheels were fitted to limited edition models, and wire wheels were offered as a factory option. Understanding which wheel type is fitted, and whether it is the original specification or a later conversion, is important when ordering wheels, hubs, and associated hardware.
Rostyle Wheels
The Rostyle became the standard MGB wheel from September 1969 and remained so to the end of production. Late rubber bumper MGBs from September 1976 had an increased wheel offset, with a resulting wider track of approximately one inch, introduced to counteract increased body roll from the raised ride height. The two Rostyle specifications are not interchangeable. To identify which type is fitted, remove the centre cap and lay the wheel face down, the wide-offset late rubber bumper wheel lies flat, while the earlier narrow-offset wheel rocks on its protruding centre.
Reconditioned exchange Rostyles are available in both offset specifications.
Limited Edition Wheels
The five-spoke alloy wheel fitted to the 1979 to 1980 Limited Edition MGB requires specific wheel nuts. The 1975 Jubilee Edition GT used the V8 cast alloy wheel finished in gold and gloss black, with sleeved wheel nuts, retaining washers, and V8 wheel centres.
Alloy Wheels
Aftermarket alloy wheels are predominantly 5.5 inches wide, wider than the standard steel rim, increasing the tyre contact patch and giving a more planted feel. They are available in 14-inch and 15-inch diameters in a range of finishes, fitting inside standard wheel arches without modification. A centre-lock option is available for wire wheel hub cars.
Wire Wheels
Wire wheels were a factory option throughout production and remain one of the most distinctive MGB specifications. The original 60-spoke 4.5x14-inch wheel in painted finish was the standard option, with aftermarket wheels available in wider and larger sizes in painted, chrome, and black finishes. All new wire wheels from MGOC Spares are of an improved tubeless design, eliminating the need for inner tubes and rim bands. Wire wheels must be centred on balancing machines using dedicated balancing cones, without them, correct balancing cannot be achieved.
Spinners & Hub Thread
Wire wheels are secured with spinners, two-eared or octagonal depending on period. The hub thread pitch changed in February 1964 from 12 TPI to 8 TPI; the two are not interchangeable. Hubs are handed, left-hand hub uses a right-hand thread and vice versa, a self-tightening arrangement that keeps spinners secure under forward motion. Two-eared spinners were original until 1968, when octagonal nuts replaced them on safety grounds.
All types are available with or without MG logo. Wire wheel and disc wheel axles differ in width, 46 inches versus 48 inches, which affects fitment when converting between wheel types.
Wire Wheel Conversions
Complete conversion kits are available for cars originally fitted with steel or Rostyle wheels. A full conversion requires replacement front and rear splined hubs, spinners, and associated hardware. The axle width difference means that conversion hubs on a steel wheel axle do not provide the same standoff as a genuine wire wheel axle, a consideration when selecting wider wheel and tyre combinations.
Wheel Nuts, Centres & Tyres
Replacement wheel nuts are available in chrome and stainless steel for original and aftermarket alloy wheels. The MGB was originally fitted with crossply 560-14 tyres; the radial equivalent is 165/80 R14. Alternative tyre sizes are available to complement the full range of wheels, the correct profile depends on wheel width, diameter, and arch clearance. The MGOC Spares range includes steel wheels, Rostyle wheels, alloy wheels, wire wheels, spinners, splined hubs, wheel nuts, centre caps, balancing cones, tyres, and all associated hardware, supported by expert advice for every wheel and tyre combination.