A kayak roof rack without crossbars

The distinction that costs people money

Do you need crossbars for a kayak rack? For a J-cradle, saddle or stacker, yes. For foam blocks, no.

The confusion is almost always about side rails. Those are the rails that run front to back along the edges of the roof on a lot of estates and SUVs. They look substantial, they look like a rack, and no kayak carrier mounts to them directly. They are the anchor points that crossbars clamp to, and crossbars are a separate purchase — usually a more expensive one than the carrier you were shopping for.

So the practical question is not “which rack” but “is it worth buying bars at all?” If you paddle most weekends and carry other things on the roof, yes. If you go out six times a summer with one boat, a foam block kit does the job for a fraction of the money and lives in a cupboard the rest of the year.

What a foam block kit actually is

Two blocks of closed-cell EVA foam that sit between the hull and the roof, plus straps that pass over the boat and through the car’s door openings, plus bow and stern lines to the tow points.

Malone publishes the numbers for its standard kit: blocks 14 inches long, a 55 lb load rating, 3.3 lb total kit weight, and two 15-foot load straps included alongside safety tie-downs. The blocks have a universal cut-out profile, so the same kit also works if you later add round, square or oval bars.

Rightline’s version includes four car clips — small hooks that give the straps something solid to attach to inside the door frame — which is the part people otherwise improvise badly. It does not publish a weight limit, which is the reason it sits below the Malone kit on this list.

Rigging it, in the order that works

1. Boat upside down, hull up, on the blocks. A polyethylene hull is at its strongest that way and the flat deck sits better on foam.
2. Blocks roughly above the door pillars, spread as wide apart as the roof allows. Wider is more stable; two blocks a foot apart in the middle of the roof are a pivot.
3. Straps through the cabin. Open all four doors, run each strap over the hull and back through the car, and buckle inside. Close the doors on the straps.
4. Bow line to a front tow point, stern line to the rear. Not to a plastic bumper — find the tow eye or a metal recovery point under the car.
5. Push the boat hard sideways and front to back. If anything moves, tighten. Then re-check after ten minutes of driving, and at every stop.

The three genuine downsides, stated plainly

Your doors are strapped shut. The straps pass through the cabin, so you cannot open the doors without unbuckling. This is the single most annoying thing about foam blocks and there is no way around it on a bare roof. Get everything out of the car first.

Wind noise. Straps through a door gap whistle. A twist in each strap breaks up the airflow and mostly stops it — an actual trick, not a myth.

They need re-checking. Foam compresses slightly as it warms and the straps go slack. A rack does not do this. If you are driving three hours each way every weekend, buy bars; you will get tired of stopping.

What does not work, whatever the listing says

• Pool noodles and ratchet straps. The noodles crush and the ratchets dent the hull. This combination appears in a lot of DIY advice and it is a bad idea on both counts.
• Straps with hooks that grab the door frame lip. They bend the seam and they let go. Use a strap that passes right through the cabin, or a proper car clip.
• Blocks alone with no bow and stern lines at highway speed. The lift on a kayak at 70 mph is substantial, and the hull straps only resist upward movement, not rotation.
• Suction-cup mounting systems for anything as long and as light as a kayak. They exist, they work for some loads, and a kayak in a crosswind is not one we would trust to them.

If your car is a sedan with a short roof, or you have a pickup, there are better answers than either bars or blocks — see transporting a kayak on a sedan and transporting a kayak in a truck bed.