Vault Hubs: End Cap Conversions For Different Axle Standards

The Race Face Vault hub has been a mainstay in the Race Face lineup for as long as we've been making wheels. Vault has endured years of abuse under riders far and wide but has also needed to evolve with the adoption of new hub standards.

Ensuring compatibility with those standards means considering axle thickness, axle length, and even the size of fork and bike frame dropouts. Over the years we’ve updated the internals and endcaps of our hubs to meet those requirements, while keeping all the features our riders have grown to love — super-quick engagement, a stiffness-optimized hub shell, low-drag labyrinth seals that keep elements out of your hub’s internals.

You landed on this page because you’re either looking for replacement endcaps for your hubs, or you may be wondering what your axle style conversion options are. Race Face makes quite a few variants of the Vault hub, some with different endcap options. To demystify the subject and help you source the right endcaps for your bike, we created the following guide.

Step 1: Find your hub model

This one is easy. Front and Rear Vault model numbers are laser-etched onto the oversized hub shell, either adjacent to or below the name Vault.

You Should see one of the following model numbers:

Front Hubs: 415, 414, J414, 412 or J412.

Rear Hubs: 424, J424, 422 or J422.

(The J prefix refers to the hub using J-bend spokes. All other Vault hubs use straight-pull spokes)

Found your model number and know your current axle style? Jump to Step 3 to see your endcaps and conversion options, or shop replacement endcaps here.

Step 2: Identify your current axle style

You have two axles on your bike – one holding the front wheel in your fork, and one holding your rear wheel in your bike frame’s dropouts. A different axle style is used for each.

Front Wheel

The most common axle style for Race Face front wheels is 15x110 Boost, but here’s a quick table showing all the front axle styles that Vault has catered to over the years.

Front axle styles are typically written like 15x110 Boost or 20x110 Boost – here's what those numbers mean.

Axle Diameter – the first number in your axle style. This is a measurement of your front axle diameter in millimetres. It’s usually printed on the axle, but you can also measure it using a set of calipers.

Hub Width – the second number relates to the width of your front hub in millimetres. Boost means that the width is larger than the previous hub width standard (100mm). This measurement is often printed on the axle but can alternatively be measured as the space between your drive side and non-drive side fork dropouts.

Exception – the difference between 20x110 and 20x110 Boost is the space between spoke flanges, and the position of the brake rotor interface. Check with your fork manufacturer to clarify whether you are running Boost or not.

Rear Wheel

The most common axle style for Race Face rear wheels is 12x148 Boost. Here’s table showing all the axle styles we have used in rear Vault hubs.

Rear axle styles are written in a similar fashion to front axle styles (see the image included above). The difference lies in how to best identify your axle’s style.

Axle Diameter – the first number in your axle style, measured in millimeters. It’s usually printed on the axle, but can also be measured using a set of calipers. Alternatively, check your frame manufacturer's website, or measure the diameter of the axle’s hole in your bike’s non-drive side frame dropout.

Hub Width – the second number relates to the width of your rear hub in millimetres. Boost means that the width is larger than the previous hub width standard of 142mm. Super Boost is even wider at 157mm. The best way to find this measurement is by checking your frame manufacturer’s website. It can also be measured as the space between your bike frame’s rear dropouts.

Now that you have your hub model and know your axle style, you can either shop replacement endcaps for your existing axle style, or continue on to understand your Vault hub’s conversion options.

Step 3: Learn your hub endcap conversion options

Race Face makes a variety of hub endcaps to let riders keep their wheels when changing bikes, forks or riding disciplines. Not all Vault hub endcaps can be used with all Vault hub models. This is because each new hub model we produced was optimized for a specific standard.

Using your hub information gathered in Step 1, use the chart below to understand your hub’s axle conversion options. Look for your Vault hub model in the left column, then see all compatible axle styles (including your current axle style) on the right.

If you’ve identified that your hub is compatible for conversion to your desired axle style, visit our Vault Endcaps page to pick up the necessary parts! Any endcaps specific to your hub’s compatible axle styles can be installed on your existing hub without special tools – simply pull off your existing endcaps by hand—or with a vice and soft jaws—and slide your new endcaps right on.

That’s it!

Still have questions? Contact us and we’ll get your rolling as soon as possible.