The Bike Trainer Tips 02： Thru-Axle Bicycle Dropout Sizes

4. Selection Reminders
First confirm your bike's specifications: Check the frame dropout area or the user manual, or measure your original thru-axle length.
Note that Boost and Non-Boost are not interchangeable: A 148mm Boost wheel cannot fit into a 142mm frame. Installing a 142mm wheel into a 148mm frame requires an adapter spacer.
Front wheels also have thru-axle specifications: Some road and mountain bikes have thru-axle front wheels, typically with dropouts of 100mm or 110mm.
When choosing a trainer adapter, go by the rear dropout: The trainer-specific thru-axle adapter needs to match your bike frame's rear dropout size (142mm or 148mm).