Adjustable length for compatibility This bike trainer axle uses spacers to adjust length and fit 12 mm thruaxle hubs in 135, 142, and 148 mm spacing. It provides a snug fit across a range of bike models. Reliable connection Tapered heads on both ends help secure the axle to most trainer mounting holes, reducing slippage during intense training sessions and keeping the setup stable. Robust aluminum alloy construction Made from 6061 aluminum alloy, the hub axle is built to withstand regular use while maintaining structural integrity throughout workouts. Frame protection enhanced The spacers are shaped to match the profile of frame dropouts, offering extra protection against potential frame damage during training. Use scenarios and applications Mixedbike setup: Switch between road and mountain bikes using the same trainer with 12 mm thruaxles, adjusting to 135/142/148 mm spacing as needed. Frequent bike changes: Use this adjustable axle to save time and avoid carrying multiple adapters when rotating between frames. intensity training: Benefit from a secure, stable connection that minimizes movement and helps protect both frame and trainer during sprints and hard efforts. Specification highlights Compatible with 12 mm thruaxle hubs at 135, 142, and 148 mm spacing Endtoend tapered heads for secure mounting Material: 6061 aluminum alloy Designed to match frame dropout shapes for enhanced protection