The axle is part of the hub, and the wheel is secured to the frame with a nut on each side. Common on city/commuter bikes, many hub-gear bikes (including many city/trekking e-bikes), and many single-speed/fixie/track bikes.
A thin 5 mm skewer passes through a hollow axle and clamps the wheel with a lever. Most commonly seen on older road bikes and older/lower-cost mountain bikes.
A 12 mm rear axle passes through the frame and hub and threads into the frame. It may have an integrated lever or require an Allen key. Common on most modern mountain bikes and most disc-brake road or gravel bikes.
1. Measure how much axle thread protrudes past the nut.
1. Remove the nut completely
2. Reinstall it and tighten it 5 full turns
3. Measure the remaining gap
If you have at least 4 mm of usable thread and the axle is maximum 10 mm in diameter, the connector plate can be mounted directly. If you do not have enough thread you need a Thule internal hub hitch adapter
On some bikes, an internal hub hitch adapter may also be useful to prevent the kickstand from interfering with your bike trailer connection.
| Thread | Typical Hubs | Adapter |
|---|---|---|
| 3/8″-26 TPI | Shimano Nexus hubs and older city bikes | 20100797 – Thule internal hub hitch adapter for Shimano |
| M10 × 1 | Many non-Shimano hubs, including some SRAM, threaded Rohloff, and others | 20100798 – Thule internal hub hitch adapter for SRAM |
| M10.5 × 1 | Older Sachs/SRAM Spectro hubs | 20110722 – Thule internal hub hitch adapter for Spectro |
| M12 × 1.25 | Many hub-motor e-bikes (thread pitch must be verified) | 20201528 – Thule internal hub hitch adapter M12 × 1.25 |
If your bike has hooded dropouts, you may need a Thule 3D drop adapter. This spacer moves the connector plate outward so it can clear the hood and sit flush against the frame.
Thru axles typically have either a flat head, or a conical (tapered) head.
Thread pitch describes how tightly the threads are spaced and must match your frame exactly.
You can identify it in two ways:
Once you’ve verified the 12 mm diameter and checked the head shape, thread pitch, and length, you can select the correct Thule thru axle from the Thule thru axle fit guide. If none of the options seem to match your measurements, please contact customer support for guidance.
The most reliable way to determine the length is to remove the axle and measure it.
Some axles or frames have dimensions printed on them, but these markings do not always represent the actual axle length. Measuring the axle directly ensures accuracy. Measure according to the head type, as shown in the illustration below.
| SKU | Product Name | Hub and Axle Type | Thread Size | Length |
|---|---|---|---|---|
| 20110722 | Thule Internal Hub Hitch Adapter | Solid axle | M10.5 × 1 | |
| 20000798 | Thule Internal Hub Hitch Adapter | Solid axle | M10 × 1 | |
| 20201528 | Thule Internal Hub Hitch Adapter | Solid axle | M12 × 1.25 | |
| 20100797 | Thule Internal Hub Hitch Adapter | Solid axle | 3/8-26 | |
| 20110800 | Thule Thru Axle | Thru axle | M12 × 1 | 161–167 (flat), 155–161 (coned) |
| 20110804 | Thule Thru Axle | Thru axle | M12 × 1 | 163–172 (flat), 157–166 (coned) |
| 20110811 | Thule Thru Axle | Thru axle | M12 × 1 | 175–184 (flat), 169–178 (coned) |
| 20110808 | Thule Thru Axle | Thru axle | M12 × 1 | 229 (flat), 217 (coned) |
| 20110801 | Thule Thru Axle | Thru axle | M12 × 1.5 | 159–165 |
| 20110805 | Thule Thru Axle | Thru axle | M12 × 1.5 | 169–178 |
| 20110806 | Thule Thru Axle | Thru axle | M12 × 1.5 | 209 |
| 20110809 | Thule Thru Axle | Thru axle | M12 × 1.5 | 229 |
| 20110802 | Thule Thru Axle | Thru axle | M12 × 1.75 | 167–180 |
| 20110803 | Thule Thru Axle | Thru axle | M12 × 1.75 | 185–198 |
| 20110807 | Thule Thru Axle | Thru axle | M12 × 1.75 | 209 |
| 20110810 | Thule Thru Axle | Thru axle | M12 × 1.75 | 217–229 |
| 20110723 | Thule 3D Drop Adapter | QR skewer |
