A caravan can shift far quicker than most owners expect once the ground tilts, the surface softens, or the load balance changes during setup.
That single detail explains why choosing the right caravan wheel chocks matters so much on New Zealand roads and campsites. A chock that is too small can slide or lose grip against the tyre. One that is too large can sit poorly against the wheel and reduce contact. Both mistakes can turn a parked caravan into a serious problem within seconds.
Across New Zealand, caravan owners deal with gravel campsites, damp grass, uneven paddocks, coastal salt air, steep holiday park entries, and soft rural terrain. Those conditions place huge pressure on wheel restraint equipment. Picking the right size depends heavily on tyre diameter and caravan weight.
This sizing guide breaks down how to match your caravan tyres and Gross Vehicle Mass to the correct OZ CHOKS® model so your caravan stays planted exactly where it should.
Match Caravan Chocks to the Tyre Before Anything Else
A surprising number of caravan owners buy wheel chocks based on caravan size instead of tyre size. That shortcut causes problems quickly.
Wheel chocks work by creating firm contact against the tyre surface. If the chock height does not suit the wheel diameter, the tyre can climb over the chock under pressure, especially on sloped ground or during loading and unloading.
Most NZ caravans from brands like Jayco NZ, Avan, and Trakmaster commonly run wheel sizes between 13 and 15 inches. That translates into tyre diameters that usually fall within the sizing range covered by OZ CHOKS® 035 through OZ CHOKS® 105.
Before buying any caravan chocks, measure the full tyre diameter from the ground to the top of the tyre. Do not measure only the rim.
Measure Your Caravan Tyre the Right Way
Getting the tyre measurement right takes less than two minutes.
Use this process:
- Park the caravan on level ground
- Engage the handbrake
- Use a tape measure from the ground to the highest point of the tyre
- Measure in millimetres for accuracy
- Record the full tyre diameter
A caravan fitted with a 14 inch rim may still have a much larger outer tyre diameter depending on tyre profile and load rating. That detail changes the wheel chock size required.
Many NZ caravan tyres sit within these approximate ranges:
- Smaller pop top caravans often sit near 600mm tyre diameter
- Mid sized touring caravans often sit near 650mm to 750mm
- Off road caravans and larger tandem axle vans can exceed 800mm
The wheel chock must match the tyre properly across the contact area. A poor fit reduces grip and stability.
Use the 20 Percent Rule Before Choosing Caravan Wheel Chocks
The safest approach is to choose a wheel chock height that reaches roughly one fifth of the tyre height.
For example, if the tyre diameter measures 700mm, the wheel chock should contact close to 140mm of tyre height.
This matters because shallow wheel contact allows tyre movement under force. Caravans carry shifting loads during entry, storage setup, towing preparation, and levelling. The tyre presses heavily against the chock during these moments.
A correctly sized caravan wheel chock spreads pressure evenly across the tyre surface and helps maintain stronger grip during loading and parking.
OZ CHOKS® model numbers directly relate to tyre sizing compatibility, making selection easier for caravan owners who want a direct fit instead of guesswork.
Check Caravan Weight Before You Buy
Tyre size alone forms only part of the equation.
The caravan weight must also match the wheel chock capacity. A heavily loaded touring caravan places very different pressure on a chock compared with a lightweight camper trailer.
Before choosing a model, check your caravan Gross Vehicle Mass listed on the compliance plate.
Things that increase caravan weight quickly include:
- Full water tanks
- Extra batteries
- Portable generators
- Tool storage
- E bikes
- Recovery gear
- Food and camping supplies
- Added solar equipment
Many caravan owners calculate based on empty weight instead of travelling weight. That mistake places huge stress on undersized wheel restraint equipment.
Heavy duty wheel chocks matter heavily once the caravan is fully packed for travel.
Match Your Caravan to the Right OZ CHOKS® Model
The OZ CHOKS® range simplifies sizing by matching tyre diameter and vehicle type directly to specific models.
Here is a quick reference table for common NZ caravan setups:
| Caravan Tyre Diameter | Typical Caravan Type | Recommended Model | Suitable Vehicle Range |
| Up to 550mm | Small camper trailers | Oz Choks® 035 | Light campers and trailers |
| 550mm to 650mm | Compact caravans | OZ CHOKS® 050 | Caravans and campervans |
| 650mm to 750mm | Standard touring caravans | OZ CHOKS® 055 | Mid sized caravans |
| 750mm to 850mm | Tandem axle caravans | OZ CHOKS® 065 | Larger touring vans |
| 850mm plus | Off road caravans and heavy vans | OZ CHOKS® 075 and 105 | Heavy caravans and 4WD towing setups |
Larger models like the 155 range move into heavier industrial vehicle applications beyond standard caravan use.
Why Material Quality Changes Everything on NZ Roads
Many caravan owners focus only on wheel chock shape while ignoring construction quality.
That approach creates problems in New Zealand conditions because cheap chocks can split under repeated loading, soften under heat, lose grip on damp ground, or crack after UV exposure. Caravan owners parked near coastal areas also deal with salt and moisture exposure year round.
OZ CHOKS® are rotationally moulded in one solid piece using heavy duty polyethylene filled with high density urethane foam. That construction removes seams and welds that commonly weaken lower grade products.
The material setup also helps the chocks stay lightweight while handling serious load pressure across uneven terrain and demanding campsite conditions.
Other important features include:Â
- UV stabilised constructionÂ
- Slip resistant baseÂ
- Resistance to oils and fuelsÂ
- No tyre damage during correct useÂ
- High visibility yellow colouringÂ
- ANSI compliant printed safety guidanceÂ
- No maintenance requiredÂ
That matters heavily for caravan owners who travel often and store equipment outdoors between trips.
Small Wheel Chocks Create Big Problems Fast
A wheel chock that barely touches the tyre creates very little restraint force.
This becomes dangerous during:
- Levelling on uneven campsites
- Hitching and unhitching
- Entering the caravan while parked
- Loading gear into storage compartments
- Parking on wet grass or gravel
A caravan only needs slight tyre movement for momentum to build, which is why the top rated best caravan wheel chocks are sized correctly instead of chosen purely by price or convenience.
Many caravan incidents begin with movement measured in centimetres.
Place the Chocks Correctly Every Time
Even the right chock performs poorly if placed incorrectly.
Use these placement habits every time the caravan is parked:
- Engage the handbrake first
- Position the chock squarely against the centre of the tyre
- Place on solid ground where possible
- Use multiple chocks if terrain slopes heavily
- Never use damaged chocks
- Never drive over the chock
- Follow the caravan manufacturer pre operation checks
Adding rope or chain retrieval accessories can also make removal easier on muddy or tight sites.
Why NZ Caravan Owners Need Dedicated Caravan Chocks
Some caravan owners use lightweight trailer chocks bought for garden trailers or small utility setups.
That shortcut rarely works well for loaded caravans.
Caravans carry higher weight, taller body profiles, and more movement during occupancy. Wind pressure, passenger movement, and campsite gradients all increase tyre force against the chock.
Purpose built caravan wheel chocks designed for caravans, campervans, vans, 4WDs, and light trucks provide stronger restraint under those conditions.
That difference becomes obvious very quickly on uneven NZ campsites after rain.
Add Wheel Chocks to Every Departure Checklist
Experienced caravan owners rarely skip wheel chocks because they know problems happen during ordinary moments involving setup, storage loading, or overnight parking.
That is why caravan chocks belong beside towing mirrors, brake checks, and tyre pressure inspections on every trip preparation list.
Final Word
The right wheel chock size can determine whether your caravan stays planted securely or shifts at the worst possible moment. Tyre diameter, caravan weight, terrain, and material quality all matter. Guesswork does not provide enough protection for loaded touring caravans moving across New Zealand roads and campsites.
If you want heavy duty caravan wheel chocks built for harsh NZ conditions, our range from FSP New Zealand® gives caravan owners direct access to manufacturer supplied OZ CHOKS® built from 100 percent virgin materials with one piece moulded construction, UV stable performance, ANSI compliant testing, and lightweight handling. We have supplied safety products since 1994 and continue to supply customers across New Zealand, Australia, the UK, and the USA. You can browse our caravan wheel chock range, request a hard copy catalogue, or send a quote enquiry online for the right setup for your caravan.
FAQsÂ
How do I know which size wheel chock fits my caravan?
Measure the full tyre diameter from the ground to the top of the tyre. Match that measurement to the OZ CHOKS® sizing range closest to your caravan wheel size and vehicle weight.
Can I use small trailer chocks on a caravan?
Small trailer chocks are often unsuitable for loaded caravans. Caravans place greater pressure against the chock during parking, loading, and levelling.
How many caravan wheel chocks should I use?
The number depends on terrain, caravan weight, and slope angle. Many caravan owners use multiple chocks for added restraint on uneven sites.
Do caravan wheel chocks damage tyres?
Properly sized OZ CHOKS® are designed to avoid tyre damage during correct use.
Are wheel chocks needed if the handbrake is on?
Yes. The handbrake and wheel chocks work together. Chocks provide an extra restraint barrier that helps reduce tyre movement during parking and setup.
