Adjustable length for versatile compatibility: This trainer axle has an adjustable length with spacers to accommodate thru axle hubs from 135 mm to 148 mm, fitting bike frames up to 176 mm wide for use across different models. Stable training experience: Tapered heads on both ends provide a secure fit in most trainer mounting holes, reducing slippage and enhancing stability during workouts. Aluminum alloy build: Constructed from robust 6061 aluminum alloy for durability and long service life under regular use without compromising strength. Enhanced frame protection: Tailored spacers fit snugly into the dropout shape to protect your bike frame from potential damage during intense training sessions. Use scenario 1: You have a road bike with a 135 mm thruaxle and frames up to 176 mm wide; this axle fits securely, supporting steady, reliable training. Use scenario 2: You cycle across bikes with 135 mm to 148 mm thruaxles; the adjustable length simplifies setup and reduces the need for multiple axles. Use scenario 3: During intensity intervals or long training rides, the tapered ends and protective spacers help maintain alignment and guard the frame against impact.