Wide compatibility for training needs This bike trainer axle offers adjustable length with spacers that accommodate thru axle hubs from 135mm to 148mm, and is compatible with bike frames up to 176mm wide for broad usability across models. Reliable connection design Tapered heads on both ends provide a secure fit in most bike trainer mounting holes, reducing the risk of slippage during training sessions. strength aluminum alloy material Constructed from 6061 aluminum alloy, this hub axle is built to withstand the demands of intense training while maintaining structural integrity over time. Protective spacer design The MTB Road Bike Thru Axle Spacers conform to the shape of frame dropouts, adding a protective layer against dropout damage during energy workouts. Use scenarios Indoor training with multiple bikes: Easily switch between road and MTB frames within the 135148mm throughaxle range and frames up to 176mm wide, minimizing setup time. Home gym with diverse bike models: Reliable, secure mounting across different hub standards without needing tools for frequent changes. intensity intervals or long sessions: Secure taper end connections and dropout protection help prevent slippage and frame damage during aggressive training.