What Size 4WD Wheel Bag Do I Need?

Choosing the right Wheel Bag is fairly straightforward once you know the outside diameter of your spare tyre.

Our Australian Made 4WD Wheel Bag comes in four sizes, covering tyres from 26 through to 37 inches. The important bit is to measure the whole tyre, rather than relying on the rim size printed on the sidewall.

Blacksmith Wheel Bag size guide

The size refers to the outside diameter of the spare tyre the bag fits around. It doesn’t refer to the diameter of the wheel rim.

How to measure your spare tyre

The most reliable method is to measure the tyre directly:

1. Leave the spare tyre mounted on the vehicle.
2. Measure from the bottom of the tyre to the top.
3. Run the tape through the centre of the wheel.
4. Record the measurement in inches.
5. Match that measurement to the table above.

It’s worth measuring rather than guessing from the tyre markings. Actual tyre dimensions can vary slightly between brands, tread patterns and models, even when the size printed on the sidewall is the same.

What if my tyre fits two sizes?

There is some intentional overlap between the sizes:

• Medium and Large overlap between 31 and 32 inches.
• Small and Medium meet around 28 inches.

If your tyre falls within an overlap, consider going for the smaller size - that will ensure you have a tight fitting bag to prevent any sag.

If you’re unsure, send us your tyre measurement and a photo of the rear of your vehicle. We’d rather help you check it properly than have you take a punt.

Should I use the tyre size printed on the sidewall?

You can use the tyre markings as a starting point, but measuring the mounted spare is easier and more reliable.

A tyre marked 265/70R17, for example, doesn’t mean the tyre is 17 inches tall. The 17 refers to the wheel rim diameter. Once the tyre sidewalls are included, the overall diameter is much larger.

Tyre manufacturers may also measure slightly differently, particularly with all-terrain and mud-terrain tyres.

What can you carry in each Wheel Bag?

The right size is primarily determined by your tyre, but capacity is still worth considering.

Small - 50L

A good fit for smaller spare tyres and compact 4WDs. There’s still plenty of room for rubbish, recycling, wet clothes, muddy boots or a light load of firewood.

Medium - 57L

The middle ground for many common touring setups. It provides a little more room without taking up unnecessary space on the rear of the vehicle.

Large - 70L

Suited to larger spare tyres and customers who want plenty of usable storage. It’s a handy size for bulky rubbish, light load of firewood and dirty gear. 

XL - 70L

Designed specifically for 37-inch tyres. The shape is made to fit the larger tyre while providing the same 70L capacity as the Large Wheel Bag.

Whatever the capacity, avoid overloading the bag with excessive weight. We recommend carrying no more than 5kg for our Australian Made Wheel Bag.

Check the space around your spare tyre

Tyre diameter isn’t the only consideration. Before ordering, check the space surrounding the spare for:

• Reversing cameras
• Number plates
• Rear lights
• Door handles
• Wiper arms
• Jerry-can holders
• Rear bars and accessories
• The clearance between the tyre and rear door

You should also make sure the bag won’t restrict the operation of a rear door or create an obstruction around legally required lights and number plates.

What if I don’t have a rear-mounted spare?

If your vehicle doesn’t have a suitable rear-mounted spare tyre, our Australian Made Tailgate Bag may be a better option.

The Tailgate Bag is designed for suitable utes and trucks where the bag can attach to the tailgate or tray area. As always, check the fitting requirements and available clearance before ordering.

You can compare both options in our 4WD Wheel & Tailgate Bags collection.

Built for the back of the fourby

Our Wheel Bags are made in Australia using:

• Dynaproofed 370gsm Australian canvas
• Heavy-duty 680gsm Australian PVC lining
• Matte-black metal buckles
• Reinforced stitching at stress points
• Side mesh pockets
• Stainless-steel front D-rings
• Double-layered mesh base for drainage

The PVC lining makes the inside easier to clean after carrying rubbish, wet boots or muddy gear, while the mesh base allows water and loose debris to drain.

Still unsure which size you need?

Measure the outside diameter of your mounted spare tyre and compare it with the size table above.

If it still sits between two options, send us:

• Your tyre measurement
• The tyre size shown on the sidewall
• A photo of the spare mounted on the vehicle
• Your vehicle make and model

We’ll have a look and help point you towards the most suitable option.

Shop the Australian Made 4WD Wheel Bag