Chris King Precision Components fully endorses the 15QR thru axle design, a standard growing in popularity due to its security, lightweight nature and stiffness. This kit is designed to make the conversion to 15QR on a standard Chris King ISO Quick Release front hub. Pull out the old, insert the new, and you're ready to go. The end result is the stiffness, stability, and convenience of the 15 QR axle system. Converting the SD (small diameter) hubshell to the 15QR will require this 15mm Conversion Kit for SD Hubshell. Please note: you will also need the adjustment clamp (#CKI151) for bearing preload.