The Best Aftermarket Wheels And Tyres For Your MGB: What's Worth Fitting

Every MGB owner gets there eventually. The car's running well, the bodywork's sorted, and then you glance down at the wheels and think something's not right.

Whether you've inherited Rostyles that refuse to balance, a set of tired pressed steel wheels or simply the urge to do something a little smarter, MGB aftermarket wheels are a subject we know well at Moss Rimmer. This guide covers the full picture: what left the factory, what fits without drama and which options are worth the money. Read this before you buy anything.

What road wheels are suitable for my MGB?

Understanding your MGB's factory wheel specification

The MGB ran on one of several factory wheel types depending on year and build spec. Early cars used a narrow 4.0-inch pressed steel wheel. Wire wheels were available throughout production as a popular alternative, running on splined hubs with knock-off spinners. From around 1969/70, the Rostyle became the standard disc wheel, stepping the rim width up to 5.0 inches. The 1980 Limited Edition brought a five-spoke GKN alloy to close out the model's production run.

What all of these share is the same bolt pattern: 4x114.3mm (the imperial equivalent is 4 x 4.5 inches). For aftermarket wheels, an offset in the range of 22 to 25mm is recommended, with 22mm being the figure most commonly cited for bolt-on alloys and the offset used by our Minator wheels specifically. Too much positive offset and the tyre sits too far inboard; too little and you'll get arch contact, almost always at the rear.

The four main aftermarket road wheel options for the MGB

In aftermarket terms, MGB road wheels fall into four broad categories. To help you get your bearings, here's the lay of the land before we go into detail on each.

• Replacement MGB steel wheels: Period-correct, suits chrome and rubber bumper cars
• MWS wire wheels: Suited to splined hub cars or owners fitting a conversion kit
• Minilite-style alloys: The classic period upgrade, works across all years in 14" or 15"
• MGB alternative wheel rims: Anything sharing the 4x114.3mm PCD can in theory be fitted, though offset and width need checking individually

One thing worth knowing before you go any further. If your car left the factory with bolt-on steel wheels and you want wire wheels, you'll need a hub conversion. We stock a complete kit covering hubs, grease caps, lock tabs and spinners. Check local regulations on spinners before committing to that route.

Which MGB aftermarket wheels are worth buying?

Knowing your options is one thing. Knowing which ones are actually worth fitting is another. Here's how we'd break it down, category by category.

MGB wheel size: is 14" or 15" better?

This question divides MGB owners more than almost anything else. Both sides have reasonable arguments, and the right answer depends on what you actually use the car for.

The case for staying on 14-inch wheels

Standard fitment for MGB road wheels across the entire production run, from 1962 to 1980, was 14 inches. The original tyre was a cross-ply 165/80R14, giving a rolling diameter of around 620mm. The modern replacement most owners settle on is a 185/70R14: slightly wider, almost identical rolling diameter at around 615mm. If you're shopping for MGB aftermarket tyres in 14" and want to avoid any speedo error, 185/70R14 is where to start.

The case for MGB aftermarket wheels 15 inch

The argument for 15 inch MGB aftermarket wheels isn't really about the wheel; it's about what tyre choice it opens up. Step up to 15 inches and a much broader range of performance rubber becomes available, particularly in 60 and 65 profile sizes. To keep the rolling circumference close enough to maintain speedo accuracy, a 195/65R15 is a sensible pairing. Getting the speedo recalibrated when switching diameter is always worth the effort.

Here's a comparison of common tyre sizes for the MGB across both rim diameters:

On rubber bumper cars in particular, 15-inch alloys suit the proportions well, and the broader tyre choice is a real benefit for anyone using their B regularly. The trade-off is ride quality. Shorter sidewalls are less forgiving on rough surfaces, and the B's suspension was set up around 14-inch rubber. Many owners who've run both tend to return to 14s for everyday use and keep a 15-inch set for the summer or track.

Will 14" x 5" wheels fit on my MGB?

The short answer is yes, on most cars and without arch modification. The longer answer involves a couple of things worth checking before you buy.

Chrome bumper vs rubber bumper: does the model year matter?

It does. Chrome bumper cars have less rear arch clearance than rubber bumper cars running at standard ride height. The rear is always the tighter end of the car on a B, and at a 22mm offset a 185-width tyre will clear on most standard cars. Go wider and you need to check your specific car rather than rely on a blanket answer, because some MGBs have a rear axle that's slightly off-centre from the factory. If yours is one of them, one side can sit closer to the arch than the other even when the offset looks right on paper. New rear springs can correct this.

What tyre width works on a 14" x 5" rim?

On a 5-inch rim, a 185/70R14 is the recommended pairing. Some owners run 185/65R14 on 5J rims without issues. Going beyond 185 in width on a 14" x 5" rim pushes you into territory that needs checking car by car rather than assumed to be fine.

MGB bolt-on wheels and MGB custom wheels at 5.5 inches wide are also available for a slightly meatier stance. At 5.5J, offset becomes more critical and it's worth measuring your own arch-to-hub clearance before committing to rubber.

MGB wheels and tyres is one of those areas where five minutes with a tape measure saves a lot of bother later. If you're not sure about fitment on your particular car, get in touch and we'll work through it with you.

You'll find MGB and MGB GT wheels for sale across our full range, covering road wheels, wire wheels and alloys in every specification. Browse MGB aftermarket wheels for sale at Moss Rimmer MGB wheels and tyres.

Disclaimer

The information in this guide is intended for general reference only. Tyre sizes, rolling diameters and fitment details are based on standard calculations and publicly available technical sources, but compatibility can vary between individual vehicles depending on specification, modification history and condition. Always verify fitment on your specific car before purchasing wheels or tyres. Part numbers and product specifications are correct at time of writing but may be subject to change. If you're unsure about any aspect of wheel or tyre fitment, consult a qualified mechanic or contact us directly before proceeding.