TBR Tyres and TPMS — Where the Sensor Goes Truck and bus radial tyres need different TPMS mounting from car tyres. Here is how valve-mount and strap-mount sensors differ, and how to choose.

TBR means a different mounting question

TBR — truck and bus radial — is not simply a larger car tyre. The inflation pressures are higher, the rims are different, the service environment is harsher and, critically for a monitoring project, the valve is often not the place you want to put a sensor.

That last point drives most of the technical discussion. On a car, a valve-mount sensor is the default and there is rarely a reason to question it. On a truck or bus, the valve is frequently metal, sometimes awkward to reach, and on some rims fitted with extensions or flow-through fittings. A sensor that screws onto the valve may work, may foul the adjacent wheel or brake component, or may simply not be serviceable by the fitter who has to work on it.

This is why the mounting question comes before the specification question. Choosing a sensor by pressure range first, and mounting second, is how projects end up with a part that meets the datasheet and cannot be fitted.

The three mounting families

Mounting	Where it attaches	Strengths	Watch out for
Valve mount	Screws onto the valve stem in place of the cap	Simplest fitment, replaceable cell in most designs, no tyre removal to service	Valve type and clearance; accessibility on dual wheels
Strap mount	Band around the rim well, sensor inside the tyre cavity	Fully protected from kerb and road damage, no external protrusion	Requires tyre removal to fit or service; band and sensor must suit the rim profile
Internal, stem-replacement	Fixed to a purpose-made stem through the rim	Secure, protected from impact	Needs tyre removal; stem must match the rim

On a truck or bus, the choice usually comes down to how the fleet maintains its tyres and how exposed the wheel is. Kerb-side wheels on a bus, in a dense city, take a great deal of impact damage. An external sensor on that wheel is at risk; a strap-mounted sensor inside the tyre is not. On the other hand, a strap-mounted sensor cannot be serviced without breaking the tyre down, so a fleet that does not remove tyres often may find it inconvenient.

Pressure range is not the only number to check

The specification table that matters for TBR has more lines than buyers usually compare.

• Pressure range, since truck tyres run well above car pressures and a sensor that tops out early is useless.
• Temperature range, because a truck tyre under load runs hot, and the sensor body sees that heat. A sensor rated for a car's thermal environment may work at the start of a run and fail the specification by the end of one.
• Position count, since a multi-axle combination passes four wheels quickly. Our own platform handles up to 256 wheel positions on one installation.
• Sealing, because the sensor lives with road spray, pressure washing and in some markets road salt.
• Battery serviceability, which decides whether a fleet can change cells at inspection or has to replace sensors.

What the sensor can actually tell you

A pressure reading alone is less useful on a truck than it sounds, because tyre pressure varies legitimately with load and temperature. Two wheels that started at the same pressure can differ measurably after an hour on the road and both be correct.

The more actionable readings are comparative and temporal.

• Temperature per wheel. An axle-end running hotter than its neighbour is a warning about a brake, a bearing or an under-inflated tyre, and it is visible long before a failure.
• Pressure trend. A tyre losing 0.2 bar a day has a slow leak. A tyre that has lost the same amount once is simply cold. Trend tells them apart.
• Cross-axle comparison. A single wheel out of step with the others on the same axle is the classic early signal.

None of this requires a sophisticated dashboard. It requires the sensor to report both pressure and temperature, and for the readings to be recorded rather than glanced at.

Why BLE is worth considering on TBR, and when it is not

There is a real case for a Bluetooth sensor on truck tyres, and it is a cost case. Our BLE platform removes the receiver from the bill of materials entirely: the sensor talks to a phone or tablet. For a fleet where a workshop or driver walks the vehicle and checks the readings, that is a substantially lower fitted cost than a receiver-based system, and the pressure span and wheel count are adequate for truck tyres.

It is worth being straight about the limits, though. A BLE sensor works in the 2.4 GHz band, with a shorter range than a 433.92 MHz system, and 2.4 GHz is more easily blocked by the vehicle itself. That is fine when the reader is close to the wheel. It is not fine when the requirement is continuous monitoring of a long combination from a fixed receiver in the cab, with the readings surfaced centrally.

Requirement	Better fit
Technician or driver reads each vehicle with a phone	A BLE sensor — no receiver, lowest fitted cost
Continuous monitoring in the cab of one vehicle, short wheelbase	Either, depending on distance
Central fleet visibility, alarms pushed to an office	A 433.92 MHz system with a receiver
Integration into the vehicle bus (CAN, J1939, serial)	A 433.92 MHz system — our industrial range

If a project needs any of the last two, the honest answer is that a BLE sensor is the wrong product, and we say so. See the truck and heavy-vehicle page for the full comparison, or the BPU120 sensor if your requirement is the first row.

A note on certification, because it comes up

Truck and bus fleets cross borders and operate under several regulatory regimes, and buyers rightly ask about type approval and radio certification. The honest position is that certification status depends on the market and the product configuration, and it should be confirmed in writing for the specific destination rather than assumed from a website. We do not describe our products as certified, and we do not publish certificate numbers. Ask us about your market and we will give the current status directly.

What to prepare before asking for a price

TBR projects are usually decided on five facts, and a supplier who does not ask for them is guessing.

• The tyre size and the normal inflation pressure.
• The rim type, including whether it is a dual-wheel arrangement.
• Whether the valve is metal, and whether extensions or flow-through fittings are used.
• How the fleet maintains tyres — does a fitter remove them routinely, or rarely?
• Where the readings have to end up: a phone in a hand, a device in the cab, or an office.

Those five answers decide mounting, specification and whether a receiver is needed at all. They are also what turn a generic quotation into a number a buyer can actually approve.