Abstract: A process for accelerating a measuring wheel of a length measurement system for sawed lumber conveyed longitudinally is provided by accelerating the measuring wheel prior to engagement with the sawed lumber to avoid slippage. The rotation of a hold-down or centering roller is used for accelerating the measuring wheel through a follower roller permanently engaged with the hold-down or centering roller. The measuring wheel is pressed by an elastic pressure element both against the follower roller and into the conveyor path of the sawed lumber. As the sawed lumber is conveyed longitudinally, it comes into contact with the measuring wheel forcing it out of the conveyor path and onto the surface of the sawed lumber while simultaneously disengaging the measuring wheel from the follower roller.