Your motorhome can sit under its maximum total weight and still overload the rear axle. Where you put kit — especially behind the rear axle — changes front and rear loads even when the total barely moves. That is why a roadside check can fail on one axle while the van “looks fine” on overall weight.
Three example loads
Example numbers table (from the diagram — not your van)
| Row | Front axle | Rear axle | Total |
|---|---|---|---|
| Empty (unladen) | 1,550 kg | 1,850 kg | 3,400 kg |
| Loaded (typical kit) | 1,450 kg | 1,950 kg | 3,400 kg |
| Loaded (with extras) | 1,400 kg | 2,100 kg | 3,500 kg |
| Example axle / van limits | 1,850 kg | 2,000 kg | 3,500 kg |
| Example result | OK | OVERLOAD | OK (total) |
In this example the total is OK and the rear axle is not. That is the whole point.
Why roadside checks care about each axle
UK enforcement and the vehicle plate care about each axle limit, not only MAM (maximum authorised mass / plated total). If a rear axle is over its plated maximum, you can fail even when the whole van is under MAM.
We do not invent what an officer will do on a given day. We do say this plainly: axle overload is a real fail mode, and guessing from “we’re under 3.5t” is not enough.
Related: Motorhome axle weights explained.
Why kit behind the rear axle hurts more
Weight hung behind the rear axle (bike rack, tow carrier, heavy garage load at the back) does not just “add to the total.” It also levers load onto the rear axle and can lighten the front. That is why a van can stay under MAM while the rear climbs over its own limit.
We will not invent a garage-to-axle calculator here. The honest fix is a Loaded weighbridge ticket with front and rear figures, then compare those to the plate in the Payload calculator.
What to do (honest path)
- Read the VIN plate axle maxima (front and rear) and the van MAM.
- Weigh the van travel-ready (Loaded) and write down front axle, rear axle, and total. See How to weigh a motorhome.
- Put those ticket figures into the Payload calculator Empty/Loaded axle check. Do not invent a split from a kit list.
- If the rear is over (or close), move weight forward, leave kit off, or reduce rear garage / rack load — then re-weigh. Do not trust a guess.
Key takeaways
- Position matters: weight behind the rear axle loads that axle harder than the same weight over the middle.
- You can be under MAM and still overload an axle.
- Plate = allowed maximum; weighbridge = today’s reading.
- A Loaded weighbridge with front and rear figures beats any diagram — including this example one.
Sources
VIN plate and public weighbridge ticket. The diagram is an example story, not a substitute for your numbers. We do not invent axle splits or safety limits.