Baby / Children Products
User Manual for Burley Ballz Thru Axle 142-148mm
Quick guide for installing the Burley Ballz Thru Axle 142-148mm. Includes verification steps, installation instructions, torque specifications, and compatibility warnings for bicycle trailers.
Table of contents
Manual images
Click an image to enlargeQuick guide from the manual
The Burley Ballz Thru Axle is designed to allow the attachment of a Burley trailer to a bicycle equipped with a thru-axle. Before installation, verify that the axle threads match your original axle and that the axle length is approximately 15mm longer than the original. Always use a torque wrench to tighten the axle to 12 Nm and the hitch to 6 Nm.
Safety warnings
- Carbon Frames: Due to manufacturing variations, Burley cannot guarantee compatibility with all carbon fiber frames. If the 20mm diameter clamping head contacts the carbon portion of the frame, it may cause cosmetic or structural damage. Consult your bike manufacturer if unsure.
- Trailer Usage: This axle is only for use when a trailer is attached. Use the manufacturer-supplied axle when not towing.
- Compatibility: The axle must be able to pass out through the drive side of the bicycle.
Axle verification
- Remove the existing thru axle from the rear wheel.
- Verify that the threads of the new Burley Ballz Thru Axle match the threads of the removed axle. If they do not match, the axle is not compatible.
- Compare the axle shaft lengths. The Burley Ballz Thru Axle should be approximately 15mm longer than the manufacturer's axle. Add appropriate spacers if necessary.
Axle installation
- Apply a drop of lubricant to the axle shaft threads and the shaft of the Burley Ballz Thru Axle.
- Insert the axle through the frame and rear wheel hub. Carefully engage the threads and hand-tighten.
- If you have an angled (Syntace) dropout, use the angled spacer (included only with the M12 x 1.0 model).
- Tighten the thru axle to 12 Nm using a 17mm wrench.
- Slide the 2mm aluminum washer over the protruding axle threads.
- Thread the Burley Ballz Hitch onto the exposed axle threads. If the hitch does not tighten against the frame and washer, an additional spacer is required.
- Tighten the hitch to 6 Nm.
Maintenance
Before each use, ensure that the Ballz are clean, free of debris, and not damaged in any way.
Practical help
Common problems
Threads do not match original axle
The Burley Ballz Thru Axle is not compatible with your bike. Do not attempt to use it, as this will damage the frame.
Axle cannot exit the drive side
The Burley Ballz Thru Axle is not compatible with your bicycle.
Clamping head contacts carbon frame
Consult your bike manufacturer to determine if the frame dropouts or swings are reinforced and acceptable for use.
Hitch does not tighten against frame
An additional spacer is required to ensure a secure fit.
Before use
- Verify thread pitch matches the original axle.
- Ensure axle is approximately 15mm longer than the original.
- Check that Ballz are clean and free of debris.
- Confirm bicycle is approved by the manufacturer for towing trailers.
- Ensure you have a calibrated torque wrench for installation.
Specs in practice
- Hitch Torque
- 6 Nm (tightening the hitch onto the axle).
- Length Difference
- The Burley axle should be ~15mm longer than the manufacturer's axle.
Images and diagrams
- Figure 1: Thread verification against the original axle.
- Figure 2: Length comparison showing the ~15mm extension.
- Figure 3: Usage of the angled spacer for Syntace dropouts.
- Figure 4-8: Step-by-step installation sequence including torque application.
Model compatibility
- Not compatible with bicycles where the thru axle cannot exit through the drive side.
- Compatibility with carbon fiber frames is not guaranteed; consult bike manufacturer.
- Angled spacer is only included with the M12 x 1.0 model.
Manual page author
David Miller
Documentation analyst
Organizes user manual content into clear summaries, with attention to model details, product context, and everyday usability.