Here's an uncomfortable exercise. Open the back of your rig and find the heaviest single object that isn't bolted down. For a lot of overlanders, it's the fridge — a Dometic CFX3 45 weighs 42 lb empty, and loaded with food and drinks it can push toward 90 lb. Now ask one question: in a maximum-effort stop from highway speed, where does that object go?
Physics has an answer, and it doesn't care how carefully you packed.
The Physics, Without the Hand-Waving
Newton's first law is the whole story: an object in motion stays in motion until something stops it. When you brake, the vehicle decelerates because the brakes act on it. Your cargo decelerates only because something — friction, a strap, a barrier, or eventually the back of your seat — acts on it.
The force required is proportional to the deceleration. In a braking event pulling around 1g — the territory of a hard emergency stop for a capable vehicle — restraining a 90 lb fridge takes roughly 90 lb of force. A genuine collision involves decelerations several times higher, which means restraint loads several times the object's weight. The numbers stack up fast:
| Object | Weight | Restraint load at ~1g stop | In a multi-g collision |
|---|---|---|---|
| Loaded 45L fridge | ~90 lb | ~90 lb | Several hundred lb |
| Full water container (5 gal) | ~45 lb | ~45 lb | 100+ lb |
| Loaded gear box | ~40 lb | ~40 lb | 100+ lb |
| Recovery boards (pair) | ~15–20 lb | ~15–20 lb | 50+ lb |
Two conclusions fall out of that table. First, friction is not a plan. The grip between a plastic fridge foot and a carpeted cargo floor is nowhere near these loads — in a real stop, the fridge moves. Second, the people in the front seats are downstream of everything in the back. In a wagon, SUV, or anything without a bulkhead, unsecured cargo and occupants share the same airspace.
This is why "it's never moved before" means nothing. Normal driving generates a small fraction of 1g. The whole question is the day that isn't normal.
The Anchoring Hierarchy
Not all securing methods are equal. From worst to best:
Level 0 — Wedged in place. Packing tight feels secure and is worth almost nothing in a real event. Soft gear compresses, and your wedge becomes a launch ramp.
Level 1 — Bungees and light hooks. Fine for keeping a jacket from sliding around. Dangerous as the primary restraint on anything heavy, because elastic restraint is exactly what you don't want — it stores energy and lets go.
Level 2 — Ratchet or cam straps to rated anchor points. The real minimum standard for heavy items. Straps rated well above the calculated load, attached to structural anchor points — factory tie-down loops or properly mounted track — not to plastic trim hooks designed for grocery bags.
Level 3 — Mechanical mounting. Bolted-down fridge slides, drawer systems, and bolted box mounts. The load path goes through hardware into the vehicle structure. This is the standard for permanently installed heavy gear.
The rule of thumb: anything you can't comfortably throw should be at Level 2 minimum. Anything that lives in the rig permanently deserves Level 3.
Fridges: Slides Done Right
A fridge slide is a quality-of-life upgrade — no more deadlifting 90 lb at arm's length over a tailgate — but it's also a securing system, and it has to be treated like one:
- Bolt the slide to structure. A slide screwed into thin floor panel just relocates the failure point. Through-bolt to the floor with backing plates, or to a properly anchored drawer system.
- Strap or clamp the fridge to the slide. The slide holds the fridge's position; the tie-down keeps the fridge on the slide. Most slides include mounting points for exactly this — use them.
- Respect the latch. A slide's travel latch is what stops 90 lb from deploying itself during braking. If the latch is worn or sloppy, fix it before the trip, not after the dent.
Boxes, Water, and the Rooftop Question
Standardized latching boxes like the Front Runner Wolf Pack Pro make securing dramatically easier — uniform shapes strap down as a single block, and latched lids mean contents stay contents. Strap the stack, not just the top box.
Water deserves special respect: it's over 8 lb per gallon and it sloshes, which means it shifts its own center of mass mid-corner. Mount containers low and strapped tight.
Don't forget the small-but-dense category either: tool rolls, recovery hardware, cast iron, and propane bottles all punch far above their size in a stop. The same hierarchy applies — latched container first, then the container strapped to structure. Fuel bottles add a second requirement: secured upright, in a spot where a leak vents outboard rather than into the cabin. And soft gear isn't exempt so much as it's the padding layer: duffels and sleeping bags belong on top of and around the hard heavy items, never as the base a heavy object is "wedged" against.
Up top, the same physics applies with a worse lever arm. A roof rack like the Front Runner Slimline II provides a proper grid of rated anchor points — that's the platform's job. Recovery boards such as MAXTRAX MKII should live in their purpose-made mounts, through-bolted, because dedicated mounts put the load path through hardware instead of hope. And remember that every pound up high raises your center of gravity and changes handling — run your roof load through the load checker against your vehicle's rack and roof limits before it becomes a cornering experiment.
The Five-Minute Pre-Drive Check
Securing isn't a one-time project; it's a habit. Before pulling out of camp:
- Fridge latched, slide latched, fridge strap tensioned.
- Box stack strapped, latches closed.
- Water tight, no slosh movement when shoved.
- Roof load: shake test on the rack, every mount and strap checked.
- Loose odds and ends — stove, chairs, the axe someone used last night — back in their homes, not on the floor.
Thirty seconds per item. It's the cheapest insurance in overlanding, and the full gear list for doing it right — anchors, straps, slides, and mounts — is in our securing and storage gear guide.
FAQ
Are factory tie-down points strong enough for a loaded fridge?
Factory cargo loops in most trucks and SUVs are rated structural points and are an appropriate anchor for strapping heavy gear — a major step above plastic trim hooks, which are not rated for restraint at all. Check your vehicle documentation for ratings, use straps rated above your calculated load, and spread big items across multiple anchors.
Do I really need a fridge slide, or are straps enough?
Straps to rated anchors are a legitimate Level 2 solution — plenty of rigs run strapped fridges safely for years. The slide earns its cost in access (no more deadlifting a loaded fridge over the tailgate) and in providing purpose-built mounting. If you buy one, bolt it to structure and still secure the fridge to the slide.
What about heavy gear on the roof — is it safe up there?
Safe if it's within your vehicle's rated roof and rack limits, mounted to rated anchor points, and you account for the handling change from a higher center of gravity. Heavy-and-low beats heavy-and-high whenever you have the choice; the roof is best reserved for bulky-but-light gear and items with purpose-built mounts.
How often should I check my tie-downs on a trip?
Every time you drive, briefly — and thoroughly after the first hour of washboard, because corrugations are world-class at loosening ratchets and walking bolts. Re-tension straps, re-check latch engagement, and re-torque rack hardware periodically on long rough-road trips.
The trail dispatch
Weight changes, rating corrections, and new gear run through the load model — one email when it matters, no filler.