In many cases, slides are required to move an application in vertical (up/down respectively rise & fall) direction.
Regular telescopic slides yield a risk of ball retainer migration when used in vertical application, since gravity will allow the ball retainer to move downwards when balls are not fully loaded and thus slip instead of rolling. This is amplified by the fact that the load being moved is not applied to the balls in this case.
Therefore Accuride recommends using linear guides with recirculating balls (such as the 0115RC range) or with synchronized ball retainer (e.g. our 0115RS,)