Carbon-Ti X-Plug steerer expander is an ultralight and useful removable accessory which allows to fix headset adjusting bolt.
The special design makes X-Plug compatible with most of steerer tubes on the market (aluminum, steel or carbon fibre ones) from Road Bicycles, Mountain Bikes or Cross Bicycles.
Its wide range of action allows it to fit steerer tubes with an inner diameter from 21.2 mm up to 25.0 mm. Headset preload adjusting bolt should be M6 diameter.

Carbon-Ti X-Plug steerer expander is very simple and fast to install, only an 8 mm hex wrench key is required. After headset preload setting, the expander could be removed allowing more weight saving. Of course in this way you can use one expander for more bicycles. For carbon fibre steerer tubes the expander works also as reinforcement so expander removing isn't recommended.

Compared to standard steel star nuts (1) X-Plug is easier to install and remove and doesn't damage inner steerer tube surface.

Star nuts (1) requires special tools for installation and also removal could be very difficult. Star nuts could be used only once and they're not compatible with carbon fibre steerer tubes because they will damage them.

Compared to standard expander used on carbon fibre steerer tubes (2 and 3), X-Plug expander, with only 14 grams, allows to save a lot of weight (up to 70% or more).

Compared to type (2) expanders, Carbon-Ti X-Plug steerer expander has got a special knurling which increase grip with steerer tubes.
X-Plug is fully CNC Al7075T6 made with a smooth and elegant shape. Comes with a nice anodized finishing for a long lasting.
X-Plug steerer expander, like all other Carbon-Ti products, is 100% Made in Italy.
