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Keep dense gear low, balance the load across the approved supports, and use the carrier’s loading diagram and restraints. There is no universal rule that every basket must carry most of its mass in its middle third. A box’s instructions may specify a different distribution.

Pre-drive checklist

  • Confirm the exact rack and carrier are approved for the vehicle and their mounting positions.
  • Weigh cargo and equipment. Apply each limit according to what it includes; use the load-rating calculation .
  • Follow the carrier’s loading diagram. Avoid concentrating a heavy object on one small area or on an unsupported end.
  • Keep dense items low and the left and right sides balanced. Consider placing especially dense gear inside the vehicle within its own loading limits.
  • Use the specified restraints and attachment points. Secure individual items against sliding, lifting and escaping, including small items.
  • Keep latches, clamps and hinges clear. Close and secure the carrier as directed.
  • Check total installed height, hatch clearance and any restrictions on opening the sunroof.
  • Inspect attachments and restraints before departure and at the intervals in the instructions, including an early stop where required.

Basket and box instructions differ

Thule’s box-packing guidance describes distributing approximately one-quarter of the load in each end section and half in the center, with heavier items in the middle. Apply the actual box manual; this is not a universal basket rule.

A basket exposes cargo to airflow. Use restraints suited to the cargo and approved anchor points. Soft bags can settle, so recheck them; stuffing gaps with soft clothing is not a substitute for restraints. A net may retain small items when its maker approves that use, but do not assume a stretch net or bungee has the capacity of a rated tie-down.

In a roof box, use the specified internal straps. The closed lid is not the cargo restraint. Keep objects from interfering with the locking mechanism and do not force the lid over an overfilled box. Use separate weather protection for sensitive items; a box is not a guaranteed dry vault.

Three packing decisions

Load Decision
Dense cooler or tools Check whether interior storage avoids using most of the roof allowance; restrain it there too
Soft luggage Keep it within the carrier’s envelope, clear of latches, and secured against settling
Long or awkward equipment Use a carrier approved for that item instead of assuming a basket and extra straps make it suitable

Do not loosen the standard for a short trip. If the load shifts while securing it, rebuild and restrain it before driving. If the route exceeds the system’s approved conditions, choose another transport method.

Choosing the carrier

Choose a roof basket for cargo that can be exposed and restrained within its instructions. Choose a roof box when enclosed storage suits the load and its dimensions, weight and loading height work. Neither solves an excessive roof load.

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