How to Attach Bike Trailer to Bicycle | Axle By Axle

You attach a bike trailer by connecting its hitch to the rear axle, matching the correct adapter for the bike’s axle type.

For the full breakdown, see our best Children’s Bike Trailer guide.

Most trailers connect at the rear wheel using a hitch plate that slides onto the axle, then the trailer tow arm locks into that hitch. The exact steps depend on one thing: what kind of rear axle your bike has. The three common standards are bolt-on hubs, quick-release skewers, and thru-axles, and each attaches slightly differently.

Getting this right matters for safety and for keeping the connection from wobbling loose mid-ride. Here’s how to handle each axle type.

Step 1: Identify Your Bike’s Axle and Dropout Type

Before buying or mounting anything, confirm what you’re working with. Burley’s compatibility guide says the first move is to identify the axle type, then determine the dropout type, before choosing a hitch.

• Bolt-on hubs — a solid axle held by nuts on both ends of the hub.
• Quick-release (QR) hubs — a hollow skewer with a lever that clamps the wheel in place.
• Thru-axles — a thicker bolt that threads through the fork or frame and into the dropout.

Bikes with 12 mm thru-axles, internal gear hubs, or certain frame shapes may need additional adapters. When in doubt, check the trailer brand’s fit guide with your exact bike model before riding.

Attaching to a Bolt-On Hub

Bolt-on hubs are the classic case, and the procedure is straightforward. The process below follows the official-style manual for this setup.

1. Remove the rear axle nut and washer on the left side of the bike (the side opposite the chainring).
2. Slide the hitch plate or tab washer onto the axle, fitting the tab into the dropout slot so it can’t spin.
3. Reinstall the nut and washer and tighten them securely. Confirm enough thread remains so the nut fully engages — a partial grip can let the hitch loosen while riding.
4. Slide the trailer tow bar onto the hitch until it seats fully.
5. Insert the locking pin through the aligned holes. Misalignment is the most common setup error, so wiggle the arm slightly if the pin won’t slide through.
6. Clip the safety strap around the bike frame and back to the tow arm. This strap is a secondary retention device, not the main connection.

Before every ride, verify the locking pin is fully latched and the strap is clipped. Some systems stay mounted on the bike between rides, so check the connection each time you hitch the trailer arm.

Attaching to a Quick-Release or Thru-Axle Wheel

Quick-release and thru-axle bikes need slightly different steps because the hitch replaces part of the wheel’s own retention hardware.

For a quick-release skewer:

1. Open the lever and remove the skewer from the hub.
2. Place the tab washer into the dropout slot so the tab seats in the frame’s notch.
3. Put the coupler plate onto the axle, then reinstall the skewer parts in order.
4. Tighten the lever to firm resistance — snug, but not so tight you strip the cam.
5. Insert the tow bar, locking pin, and safety strap as described above.

For a thru-axle:

1. Remove the thru-axle from the frame.
2. Slide the trailer hitch or adapter onto the axle, usually on the disc-brake side of the rear wheel per Wike’s guide.
3. Reinstall the axle and torque it to the spec written on the frame or adapter — common values run about 12–15 Nm depending on the system.
4. Attach the tow bar, secure the locking pin, and clip the safety strap.

Common Setup Mistakes and How to Avoid Them

Most attachment problems trace back to the same few errors. A quick checklist before the first ride catches them all.

• Wrong adapter for the axle type. Bolt-on, QR, and thru-axle hitches do not interchange. Confirm which standard your rear wheel uses.
• Locking pin not fully seated. The pin must pass completely through the hitch and tow arm. If it half-engages, the arm can release on a bump.
• Safety strap left off. The strap is a backup — clip it every ride, even on short trips.
• Insufficient thread on bolt-on hubs. If the nut can’t fully engage the axle threads, the whole hitch can pull free under load.