Why Axle Weights And Tyre Pressure Matter
Axle weight tells you the true load on each tyre. From that you set the correct cold inflation pressure. Get it right and you improve traction, cut fuel use, protect soil, and extend casing life. Get it wrong and you risk heat build‑up, shoulder wear, bead unseating, poor steering and weak braking.
IF and VF tyres carry more load at the same pressure, or the same load at lower pressure, within speed/duty limits:
- IF: about +20% load at the same pressure, or −20% pressure at the same load
- VF: about +40% load at the same pressure, or −40% pressure at the same load
Always set pressure for the heaviest duty you face (top road speed, field speed, and any cyclic loads). For fundamentals, see our IF/VF load–inflation setup and read about ground pressure and soil protection.
Tools, Data And Setup You Need
Work with cold tyres: parked in shade for 3+ hours.
- Level hardstanding, wheel chocks, a spotter
- Calibrated weigh pads or a weighbridge; drawbar scale for trailed kit
- Tape measure, notebook/spreadsheet
- Latest maker load–inflation tables (e.g. Michelin, BKT, ATG/Alliance)
Record machine details:
- Ballast fitted, fuel level, loaders/front weights, hitch type
- Axle spacing, singles/duals per axle, rim profile and rating
- That rims suit IF/VF bead seats and loads (check ratings and W/DW/TW profile)
If in doubt, see our guide to rim profiles and IF/VF bead seats.
Prepare The Tractor And Implement For Weighing
- Configure the machine as used: working ballast and duals, typical tank levels, implement fitted
- Record current cold pressures; inspect casings, valves and rims
- Confirm wheel fixings, offsets, PCD and dish match spec; torque to values
- Work on level ground with chocks and a spotter
Fieldens OTR Ltd follows ISO 9001 methods for measurement, fitment and verification. The same discipline helps you repeat results and avoid guesswork.
This image was generated with AI and may not always represent the product or service exactly.
Method A: Weigh Pads Step‑By‑Step (Mounted/3‑Point Implements)
- Tractor only: place each axle on pads. Record F0 (front) and R0 (rear).
- Hitch the implement. Raise to transport height and record Fr (front) and Rr (rear).
- Lower to working depth/carry position (for semi‑mounted) and record Fl and Rl.
Hitch transfer (raised) = Rr − R0. Working transfer (lowered) = Rl − R0. Use these figures to define worst‑case road and field axle loads. Note singles/duals on each axle—you will divide axle load by tyre count when setting pressures. If ground impact is a concern, see our flotation and ground pressure calculation.
Method B: Weigh Pads And Drawbar (Trailed Implements)
- Support the drawbar on a calibrated vertical scale at hitch height. Record nose weight N.
- Hitch to the tractor, release brakes, and weigh tractor front and rear axles (TrF, TrR).
- Weigh trailer axles on pads or a weighbridge.
Check TrF + TrR + trailer axles = total gross. Use N to understand how hitch height and loading transfer weight onto the tractor’s rear axle. For safe transport, confirm speed and loading against the maker’s limits and UK guidance in trailer load and speed ratings.
Method C: Estimating Axle Loads Without Weigh Pads
- Start with known masses for the tractor (with ballast/fluids) and implement.
- Mounted kit: estimate hitch transfer using lever arms. Use a simple moment balance about the rear axle to split loads onto front and rear.
- Trailed kit: use stated nose weight or a typical manufacturer percentage of gross.
- Add operator and any payloads (seed, liquid, bales, tanks).
- Cross‑check that the front axle retains at least 20–25% of total in transport for stable steering.
If you are near tyre, rim or axle limits, prioritise an actual weigh.
Convert Axle Loads To Per‑Tyre Loads
- Per‑tyre load = axle load ÷ number of tyres on that axle (adjust for duals/triples).
- Apply any maker guidance on uneven inner/outer sharing at higher road speeds.
- Add allowances:
- Side slopes: +5–10% to uphill tyres
- Dynamic peaks: loader work, potholes, headland turns—add the margin advised by the tyre maker
- Choose the worst case across road and field; fronts often peak on road, rears in draft work.
This image was generated with AI and may not always represent the product or service exactly.
Set IF/VF Pressures From Load–Inflation Tables
- Open the table for your exact size, construction (standard/IF/VF), and speed/duty line (transport, cyclic, field).
- Find the next value above your worst‑case per‑tyre load; read off the pressure.
- Apply dual/triple corrections if specified.
- Never set below the tyre’s minimum seating pressure or the rim’s pressure limit.
Set cold pressures, re‑check after 24 hours, then refine. If you run CTIS, create field and road presets that match the table data and your duty cycle. For retrofit options and best practice, see our CTIS guide for tractors and trailers.
Balance, Ballast And Wheel Choices That Protect Tyres And Soil
- Target 20–35% static weight on the front axle in transport for steering control.
- Aim for 8–15% slip in field on 4WD; adjust ballast and pressure to meet it.
- Add/remove front/rear ballast to hit targets, then re‑check loads and pressures.
- Strip unneeded ballast for roadwork to cut heat build‑up.
- Match rims to tyre technology and rating; consider bespoke wheels/offsets for track width and clearance.
- Where puncture risk or industrial duty is high, Fieldens OTR Ltd can advise when Polycoat Tyrefill makes sense.
- Avoid heavy liquid ballast in agriculture unless essential; adjust pressures if used.
Verify In The Field And Maintain
- Check footprints in work: aim for a long, even contact patch without lugs burying or scuffing.
- Short footprint = pressure likely too high
- Crushed shoulders = pressure likely too low
- Confirm slip from tractor readouts or GPS; fine‑tune ballast and pressure.
- Check pressures weekly in season and before long road runs using a quality gauge.
- Record settings per implement; re‑weigh if you change implement, ballast, tyre size, duals, or add loaders/saddle tanks.
Small changes can make large differences to casing temperature and life.
Compliance, Limits And When To Ask For Help
- Never exceed tyre, rim or axle ratings.
- Observe UK limits on agricultural vehicle weights, axle loads and speeds.
- Set pressure for the maximum duty, not the average day; build in margin when close to limits.
When you need a bespoke setup—duals, rowcrops, or flotation—Fieldens OTR Ltd will measure and build to ISO 9001 standards, supply leading brands, and fit on‑farm. We help you validate loads and pressures and keep you legal and productive.
Services And Further Reading
Fieldens OTR Ltd supplies and fits agricultural and industrial tyres and builds wheels to specification. For tractors, loaders, sprayers and trailers, we match casing, rim and duty to your work and region. Explore our range of tractor tyres and speak to our team for a measured solution.
For deeper reading, revisit IF/VF load–inflation tables, ground pressure, CTIS and ballast choices. Use this guide to document settings per implement and protect your soil and tyres across the season.
FAQs
Do I Need Weigh Pads To Set Tractor Tyre Pressures?
No, but they are the most accurate method. You can estimate from known masses and lever arms, then validate with a weighbridge or practical checks. If you’re near limits, get an actual weigh.
What Is “Cold Inflation” And Why Does It Matter?
Cold inflation is the pressure set with tyres at ambient temperature, parked out of sun for at least three hours. It ensures readings match the manufacturer’s load–inflation tables.
How Much Weight Should Stay On The Front Axle In Transport?
Keep at least 20–25% of total weight on the front axle for stable steering and braking. Add front ballast or adjust hitch settings if needed.
Can I Run Different Pressures For Road And Field?
Yes. Set pressures to the heaviest duty you face, or use CTIS to switch between safe road and field presets based on the tables.
How Do Duals Affect Per‑Tyre Load And Pressure?
Divide the axle load by the number of tyres, then apply any dual/triple correction in the tables. Some makers assume uneven inner/outer sharing at speed.
When Should I Re‑Weigh My Tractor And Implements?
Re‑weigh after any change to implement, ballast, tyre size, duals, loader fitment, or tank additions. Also re‑check at seasonal shifts when duties change.