This article is dedicated to the problems of using bolt-on wire wheel adapters on the MGA. The first point to make and to remember is that the wire wheel rear axle is 7/8-inch shorter on each end to allow for length of the splined hub. If you bolt-on a splined hub like the TR6 part shown immediately below, it will offset the tires outward about one inch on each side to increase track width about two inches. Some people like (or don't mind) the wider looking stance, but this positions the tires perilously close to the rear fenders. It can work with standard size tires on original configuration wire wheels, but with the wheels set outward that far it is unlikely to accept any tires wider than standard issue (about 165-80R15 maximum tire size). In other words, this only works with more or less standard size tires, and it makes the car look odd. Check out these pictures for comparison.

Additionally, these adapters want to use hex drive round head bolts for attachment (see photos below). To use hex nuts on the standard studs you need to cut the studs shorter and round off the outer end of the nuts to clear the inside of the wire wheel hub. If you don't to this the wheel will hit the studs or nuts before mating with the intended conical seat at the inner end of the hub. When not properly seated the wheel will work loose, quickly damaging the wheel (possibly hazardous to your life).

A possible alternative to cutting the studs shorter is to install a spacer plate just inboard of the splined adapter hub, as shown above and below. This will set the wheel and tire even farther outboard, but it makes the process reversible without replacing wheel studs.

Below are pictures of a slightly different approach to bolt-on wire wheel adapters. This is called "Dental Splines" where very short coarse splines are positioned around the outer edge of the bolt-on adapter flange, and special wire wheel hubs are required for mating. I think these are single source parts, rather expensive, and slightly heavier than standard wire wheel parts. There are a few advantages to this design. The hub itself can transmit considerably higher torque for high performance cars, the splines are less prone to wear, and the wheels are less likely to stick on the splines after long periods of inattention. This design does not necessarily set the wheel centerline any farther in or out, as it depends on design angle of the spokes to determine offset of the wheel.

I am not an advocate of bolt-on wire wheel adapters specifically because it increases the track width setting the tires closer to the fenders, so I will generally recommend against it. But if you insist on doing this, there is now a redesigned rear hub wire wheel adapter from Moss Motors that can reduce the problem some.

On November 30, 2011, Kelvin Dodd from Moss Motors wrote:
"Our rear axle wire wheel conversion hub mounts the drum differently than the original WW hub. Instead of the drum being secured on the WW hub studs by nuts, which require a certain amount of wheel offset to clear. The adapter hub has threaded holes and the drum is secured by special half height head bolts. This allows the wheel to be situated about 1/2" closer to the drum than on the original hubs. The rear track is still slightly wider than that of a steel wheel car, but with a reasonably centered axle there should not be rubbing problems with a 165-14 tire (relating to MGB). If the customer wants to go with wider tires and wheels, I would recommend converting the axle assembly".

Addendum June 20, 2018:
The most recent Moss Motors rear splined hub adapter uses special thin lug nuts which are "double-ended" with the tapered bevel on both ends of the nut. Using standard lug nuts here with flat front face would definitely interfere with seating of the wire wheel onto the adapter.

The Moss adapter installation instructions also call for cutting the rear wheel studs shorter. As alternative, you can replace the long studs with shorter studs from the front hubs of an MGA 1500 drum brake car. If you happen to be converting your 1500 from drum brakes to front disc brakes at the same time as installing wire wheel adapters, you may have the old 1500 drum brake hubs left over. In this case you can use the old front studs without having to buy new ones for the rear splined hub adapters.