As you can see in the tech drawing, the Classic tm weights and throttle locks are 1.999" long.  With straight bars like drag bars or MX bars, this means a nearly 4" increase in width.  However, the more the bar ends are angled toward the rider, the less the width goes up.  For instance, a 30 degree pullback on the grips will grow just less than 3.5" in total width with the addition of weights or a throttle lock.