Universal Thru Axle – The Complete Guide

Introduction

The Axle and Fast-Release Dropout system ensures that our Rear Systems (Pannier Racks, CargoPacks and SpeedPacks) are ‘quick release’ from the bike. Proven to be the strongest mounting system in our tests, we pride ourselves on engineering an axle that will fit almost any bike.

Most modern bikes use a standard 12mm thru axle for the rear wheel. These range in width to fit road, gravel and mountain bikes. However, less well-known is that the specific thread pitches vary across bike makes, models, and years. We understand that finding the thread pitch used on your bike(s) isn’t always easy. To help, our website features an Axle Finder and a Thru Axle PDF sizing guide. Our Customer Service Team are also on hand to help if needed.

This is why we recommend the Universal Thru Axle, a 12mm thru axle that comes in 2 parts: driveside and non-driveside.

What does the Universal Thru Axle include?

Included in your Universal Thru Axle box is a single non-driveside part. Then, you have the four driveside parts covering the most common thread options of 1.0mm, 1.0mm ‘speed release’, 1.5mm, and 1.75mm. The Universal Thru Axle includes two 8mm central extenders to make it wider if needed. Use this for bikes with BOOST hub spacing and/or SRAM T-Type Transmission derailleurs.

Finally, your Universal Thru Axle comes with four spacers for alignment. The cone spacer (required if your original axle has a conical inner face) fits closest to the frame to mimic the profile of the bike’s original spacer. These spacers can be stacked together on their flat sides. This is to achieve the best alignment with your axle in the frame, ensuring the arch sits as centrally as possible over the rear wheel.

You can purchase both the driveside and non-driveside spare parts individually on our Spares Page and any additional Thru Axle Spacers too.

Why choose the Universal Thru Axle over the Single 12mm Thru Axle?

There are several advantages to choosing our Universal Thru Axle over our solid 12mm Thru Axles, as described below.

Fits Multiple Bikes

One advantage of the Universal Thru Axle is that you can use it on multiple bikes if each uses a different thru axle thread size. Simply remove the Universal Thru Axle from one bike, and change the driveside end to the corresponding thread pitch of the new bike. Insert the axle into the other bike, using the correct spacers to align on the non-driveside for the best fit. It means you don’t have to purchase a different 12mm Thru Axle for each different bike if they vary.

Add Central Extenders

The central extenders are useful additions, especially when using a bike that has ‘hooded’ dropouts. These can be found on some steel or titanium frames, such as the Sonder Camino Ti. The extenders allow you to make the axle longer by up to 16mm, meaning the axle mounting points extend beyond the ‘hooded’ elements of these frames. This feature is also required for some MTBs using 148mm BOOST spacing. This applies to bikes like the Specialized Epic and Santa Cruz Blur, for example, where the single 12mm Thru Axle is too short.

The Universal Thru Axle is also required for any bike using SRAM’s newest T-Type Transmission derailleurs. These derailleurs make the dropouts wider, again, making the standard 12mm Thru Axle too short. Therefore, use the Universal Thru Axle with the central extenders added to ensure a proper fit. More on this below.

Your bike may require more than just the Universal Thru Axle

---

Many brands have transitioned to the SRAM UDH or T-Type Transmission standards on newer models in recent years, too. An additional feature to consider when fitting the axle to your bike is whether your bike uses the Universal Derailleur Hanger (UDH) or XX/XO or GX Transmission derailleurs. The 8mm opening of the bolts designed to fix the hangar to the frame and axle is too small for the Tailfin Thru Axles to pass through, which is why we’ve worked with SRAM to create the UDH/Transmission Adaptors that allow you to use our axles on your bike.

We supply adaptors and locking nuts for other bikes, too, such as Salsa and Pearson bikes, which feature a similar bolt, but don’t use the UDH standard. These can be chosen during configuration or on our Spares Page.

All three SRAM adaptors fit with the 1.0mm Axle Thread Pitch – included in the Universal Thru Axle. 

---

Choosing the adaptor you need is possible on stage 3 (‘Your bike’) of our Rear Systems Configuration, where we list all the options you may require.

Whether your bike requires any of these adaptors will be shown when using our Axle Finder. Alternatively, if you’re still unsure, you can contact us via email too.

Fitting the Universal Thru Axle

How you insert and remove the Universal Thru Axle is worth noting:

• Fit the wheel and install the Tailfin Universal Thru Axle.
• Tighten to 8-10Nm with a 5mm hex key on the non-driveside (left).
• When removing Universal Thru Axle (and to avoid the axle separating within the wheel), undo it from the driveside (right) of your bike.

For bikes that require an adaptor, check whether you need to install it before or after the axle. e.g. You must install SRAM UDH/Transmission adaptors before the axle.

Is the Universal Thru Axle as strong as the Single 12mm Thru Axle?

When designing the Universal Thru Axle, we used the cross-section of common solid thru axles as a reference. We ensured that the central part of the Universal Thru Axle (including the 1.0mm central threads) would equal the same amount of material. Therefore, they would match the strength of a single Thru Axle when tightened together.

Each part of the Universal Thru Axle is individually CNC-machined from solid stock 7075-T6 aluminium alloy. They are further processed with an anodised finish in classic Tailfin Black. 7075-T6 alloy was chosen as it has the ideal attributes for this application: high strength-to-weight ratio, resistance to fatigue, and corrosion resistance. 

Assembly Guides

For assembling your Universal Thru Axle, you can use our assembly guides below:

Frequently Asked Questions (FAQ)