Towbar Bike Racks in NZ: How to Choose, Fit and Use One Safely

Hitch-mounted bike racks

The term "hitch-mounted bike rack" is often used broadly for rear-mounted bike racks, particularly in overseas product descriptions. In New Zealand, the important distinction is the actual attachment. Some carriers clamp to a towball, while others slide into a removable or fixed receiver.

A platform carrier supports the wheels on trays and is often easier to load. Vertical and hanging carriers can carry more bikes in less rearward space, but the loaded weight and leverage still need to be checked.

Roof-mounted racks are an alternative if you do not want to use the towbar, while spare-wheel racks can suit some SUVs and 4WDs with an externally mounted spare.

What towball size does a bike carrier need?

The two common ball sizes you may encounter in New Zealand are 50 mm and 1 7/8 inch, which is approximately 47.6 mm. They are different sizes. A towball bike carrier must be fitted to the ball size it is designed to clamp or mount onto.

Do not use the towbar's trailer towing capacity as the bike-rack limit. A 3,500 kg towing rating describes trailer towing capacity. It does not mean the towbar can support a 3,500 kg vertical accessory load.

Why does leverage matter?

A rear-mounted bike carrier holds its load behind the towball or receiver. Moving the same weight further away from the vehicle increases the leverage acting on the towbar and its mounting points.

This becomes more important with long platform racks, receiver extensions and carriers that hold several bikes. Keep the bikes as close to the vehicle as the carrier design allows and do not add extensions unless the towbar and carrier setup permits them.

What should you check with a 4-bike towbar rack?

A four-bike rack can reach the towbar limit surprisingly quickly because the rack itself is part of the load. Four bikes also place the outermost bike further behind the vehicle, increasing leverage.

For example, a 20 kg carrier plus four 15 kg bikes gives a static loaded rack weight of 80 kg. If the bikes weigh 20 kg each, the total becomes 100 kg. Those totals need to be checked against the carrier, towbar and vehicle limits before the rack is used.

Already have a Hayman Reese towbar but are unsure about its rating or need wiring for a rear light board?Find a Hayman Reese installerwho can help check the existing setup.

Two e-bikes can weigh more than four lightweight road bikes. Weigh or check the specified weight of each bike and include the rack itself in the total.

If the bike design allows the battery to be safely removed for transport, taking the batteries off can reduce the weight on the carrier and make the bikes easier to lift. Transport removed batteries as directed by the bike or battery supplier.

Also check tyre width, wheelbase and frame shape. Some e-bikes need wider wheel trays or different frame retention than a conventional bike.

Supplementary plates for bike carriers

A supplementary plate must carry the same characters as the plate issued to the vehicle. NZTA says supplementary plates can be used when a temporary attachment, such as a bike rack, obscures the normal plate.

Only an authorised plate is legal. Do not make your own copy of the registration plate.

Rear lights and indicators

Bikes carried across the rear of the vehicle can cover tail lights, brake lights or indicators. If required rear lights are obscured, use a rear light board or other compliant temporary lighting so drivers behind can still see the vehicle's signals.

This is especially worth checking before buying a rack for several bikes. The first bike may leave the lights visible while the third or fourth bike blocks them.

A load carried on a car must not extend more than 4 metres behind the rear axle or more than 1.275 metres either side of the vehicle's centre-line.

If the load extends more than 1 metre behind the vehicle, it needs a warning flag during daylight. NZTA specifies a white or fluorescent red, orange or yellow flag at least 400 mm by 300 mm. During the hours of darkness, the projecting load must use the required rear-facing red light or lights.

Loads that extend more than 200 mm beyond either side of the vehicle body also require warning devices. During darkness, side-projecting loads require the lighting specified by NZTA.

For a bike carrier, measure to the furthest projecting part of the loaded bikes. A handlebar or wheel may extend further than the rack frame itself.

See our Toyota Hilux towbars, Nissan Navara towbars and Ford Ranger towbars for vehicle-specific fitment information.

For general information about towing capacity, towbar ratings and tongue weight, see our guide to towing a trailer in NZ.