Car bike racks: hitch, roof or trunk, and the plate and light laws

There are three ways to carry a bike on a car: a hitch rack (in the trailer-hitch receiver), a roof rack (on crossbars) or a trunk rack (strapped to the trunk or hatch). The hitch rack is the easiest to load and the one that carries the most weight, including e-bikes; the roof rack keeps the trunk free but costs the most fuel and limits bike weight; the trunk rack is the cheapest but is the most likely to hide your license plate and lights. Whatever you choose, the plate has to stay readable in most states, and the bikes shouldn’t block your tail lights.

The three types compared

Prices and load ratings from Thule’s US range, checked on October 19, 2026, as a market reference:

Hitch racks

A hitch rack slides into the receiver and locks in with a pin. There are two styles: hanging racks, where bikes hang by the top tube from two arms (cheaper, 37.5 lb per bike on Thule’s Apex and Helium Pro), and platform racks, where the bike sits on its wheels in trays (easier on carbon frames and the right choice for e-bikes). Thule’s e-bike platform racks are rated for 55-80 lb per bike: the EasyFold XT 2 for 65 lb, the Epos for 75 lb and the Vero for 80 lb.

Before you buy, check two numbers:

• Receiver size. Receivers come in 1.25 in and 2 in. Heavy-duty and e-bike racks may be sold only in the 2 in version, so check the listing for the exact model.
• Tongue weight. The rack plus the bikes press down on the hitch. Your hitch’s tongue-weight rating is on its label and your vehicle’s limit is in the owner’s manual. Do the math: a 50 lb rack with two 60 lb e-bikes is 170 lb on the hitch.

Some platform racks (like the Epos with lights) carry their own light board, which helps when the bikes hide your tail lights.

Roof racks

Roof racks need crossbars and one rack per bike. Thule’s US roof racks carry 40-44 lb per bike, which covers road, gravel and most mountain bikes but not e-bikes, and lifting a bike over your head onto an SUV roof is a workout. Add the crossbars, racks and bikes and stay under the roof load limit in your owner’s manual.

Two classic roof rack mistakes: driving into the garage with the bikes up (stick a note on your garage remote) and forgetting the bikes at a drive-through or parking garage height bar.

Trunk racks

Trunk racks hook onto the edges of the trunk or hatch with straps and padded feet. They’re the cheapest option (Thule’s start at $179.95) and need no hitch or bars, but they carry only light bikes (33-35 lb per bike), the trunk stays closed, and the bikes usually sit right over the plate and lights. Check that your car is approved on the rack maker’s fit guide: spoilers and glass hatches often aren’t.

Fuel economy: what the rack costs you

Wind resistance is what hurts mileage. According to fueleconomy.gov, run by the US Department of Energy and the EPA, a large roof cargo box can reduce fuel economy by around 2-8% in city driving, 6-17% on the highway and 10-25% at Interstate speeds (65-75 mph), while rear-mounted carriers cost only 1-2% in town and 1-5% on the highway. Bikes on the roof aren’t a cargo box, but they’re a big, messy shape up in the airflow, so expect the roof to cost more than a hitch rack. The site’s advice applies to racks too: take it off when you’re not using it.

Plates, lights and the law

There’s no single national rule for bike racks: each state writes its own plate and lighting laws, and enforcement varies. A few examples we could verify:

• New York: Vehicle and Traffic Law § 402 says the view of the number plates must not be obstructed by any part of the vehicle or “by anything carried thereon”.
• California: Vehicle Code § 5201 requires plates to be mounted so they’re clearly visible and kept clearly legible.
• Michigan: a 2018 law (House Bill 5100) stopped removable rear-mounted items like bike racks and trailer hitches that block the plate from being grounds for a ticket, according to WCMU Public Radio.

In practice:

1. Check that the plate is readable from behind with the bikes loaded. If it isn’t, move a bike, use a rack with a plate holder, or mount a secondary plate bracket if your state allows it.
2. Make sure people can see your brake lights and turn signals. If the bikes block them, use a rack with its own light board or a plug-in trailer light bar.
3. Look up your state’s rules in our US bike laws section, or on your state DMV’s site, especially before a long road trip across several states.

E-bikes on a car

For an e-bike, the only realistic option is a platform hitch rack rated for e-bikes. If your e-bike weighs more than 44 lb (20 kg), as most full-size ones do, it’s over every Thule roof and trunk rack’s rating. Before you drive:

• Remove the battery and carry it inside the car, out of the sun. It makes the bike lighter to lift and protects the battery from rain, road grit and theft (more in e-bike battery care).
• Remove the display if it comes off.
• Use a ramp if the rack has one: lifting a heavy bike onto a tray at bumper height is how backs and paint get hurt.

If you’re still choosing an e-bike, weight is one more thing to look at: see how to choose an e-bike.

Common mistakes

• Not re-checking straps after the first few miles. Straps stretch and bikes settle. Stop after 10-15 minutes and tighten everything.
• Leaving bikes on the rack overnight. Rack locks slow thieves down; they don’t stop them.
• Pedals and handlebars hitting the car or each other. Alternate bike directions on hanging racks and pad contact points.
• Ignoring the hitch or roof limit with heavy e-bikes or a 4-bike load.
• Driving through an automatic car wash with the rack on. Take it off.

Traveling farther? Compare flying with your bike and taking it on the train.

Updated October 19, 2026 ·Report an error on this page