Run-flat inserts explained: bands, rubber, plastic, beadlocks
A guide for fleet buyers to bands, rubber and plastic inserts, beadlocks, single-piece and multi-piece designs, and split-rim or one-piece wheels.
Tyron Asia technical team · 2 November 2026 · 4 min read
A band locks a flat tyre to a standard wheel for a medium distance at reduced speed, while an insert gives the tyre something to run on for longer. The right choice depends on how far the vehicle must travel on a deflated tyre, what terrain it works on, and whether its wheels are one-piece or split-rim.
Fleet buyers often hear these terms used loosely. This guide sets out what each one means.
Driving a car on normal wheels? See Run-flat tyres vs the Multiband or check your car.
Start with the wheel
One-piece wheels are the standard wheels on most road vehicles. The tyre is levered on over the rim. Anything fitted inside has to be fitted in the same way, or be flexible or segmented enough to go in.
Split-rim or bolt-together wheels come apart in two or more pieces. This lets a tyre and a rigid insert be assembled around the wheel, and it makes room for a beadlock. Changing a vehicle to these wheels is a bigger decision, since it means replacing the wheels themselves. Assembly should follow the wheel maker's procedure and be done by trained staff.
Safety bands
A band sits in the wheel well of a standard wheel. It stops the tyre beads dropping into the well, which keeps the deflated tyre locked in place.
Tyron's Multiband is this type of system. It converts a standard wheel into a safety wheel by locking the tyre to the wheel, which helps maintain steering, cornering and braking control during a high-speed blowout. It also lets the vehicle cover a medium distance at reduced speed to a safe stop, even with two or more deflated tyres. In TÜV testing on a range of vehicles it completed 3 km at 80 km/h plus a further 3 km at 50 km/h through a handling course and slalom.
Bands suit road vehicles on standard wheels, such as ambulances, vans and police cars, where the task is to get to a safe place. A band is not a long-range system.
Inserts
An insert is mounted on the rim, inside the tyre. It fills part of the tyre's air space. When the tyre deflates, it runs on the insert and does not collapse onto the rim. This gives a longer range than a band.
Rubber inserts
Rubber absorbs shock from potholes and kerb strikes, and it is a compliant material. Tyron's ATR (All Terrain Rubber) range is in this group.
Plastic and composite inserts
These are rigid. Tyron's technical paper describes them as lighter and less expensive to make, and generally designed to fit the existing single-piece wheel, and says they work very well on vehicles using public roads. Where road conditions are poor or vehicles operate off-road, Tyron's position is that plastic runflats can break, or cause the wheel to break, even in normal driving. Buyers should weigh that view against each supplier's evidence and ask for test data on their own operating conditions.
Single-piece and multi-piece inserts
Single-piece inserts are one continuous ring. For many years, a single-piece rubber insert has been the military industry standard. These generally need a hydraulic press to squeeze them in and out of the tyre. Tyron's ATR-SP is a low-cost option in this format.
Multi-piece inserts are built from modular segments. Tyron's patented ATR-MP does not need a hydraulic press, so it can be fitted and removed in the field, and it fits military split rims with no special tools. That reduces the logistics of moving tyres and presses around, which matters for forces working far from a workshop.
Custom inserts for one-piece wheels. Vehicles on standard single-piece wheels have traditionally been limited to bands or plastic inserts. ATR-Custom is Tyron's customised service to produce rubber runflats for these wheels.
Beadlocks
A beadlock clamps the tyre beads against the wheel flanges. It stops the tyre slipping on the wheel at low pressure. It also matters for vehicles that lower their tyre pressures off-road. Beadlocks can be separate parts or a function of the wheel and insert together.
Tyron's ATR-Beadlock is made of rubber. It is produced wider than needed, so that it compresses and takes up differences in bead thickness and tolerances.
Tyron's R-series wheels
R4 and R7 wheels are designed to make ATR installation easy and quick.
- R4 Forged and R4 Cast: aluminium bolt-together wheels, lighter than steel.
- R6: steel 3-piece split-rim wheels, designed for buses and cash-carrying vehicles.
- R7: steel bolt-together wheels.
With an ATR fitted, these wheels are designed to give beadlock to meet Finabel standards. Our guide to Finabel run-flat testing explains what that means and what to ask for.
How to narrow the choice
- How far must the vehicle go after a tyre fails? A medium distance at reduced speed, to a safe stop, points to a band. Tens of kilometres points to an insert.
- What is the terrain? Rough or off-road use favours rubber, and may call for a beadlock.
- Can you change the wheels? If not, look at bands, ATR-Custom or plastic inserts.
- Where will tyres be changed? If it may be in the field, look at multi-piece designs.
- How heavy is the vehicle? Armoured vehicles add load. Check every part against the vehicle's axle weights.
- Do you use central tyre inflation? If so, ask how the system handles beadlock and sealing.
Dimensions and load tables are available on request, and prices depend on your requirement. To discuss which system suits your vehicles, send us your vehicle types and rim sizes.