The 5000 needed more gripping strength providing a stronger connection between the drummer and kick drum. So DW developed the Tri-Pivot Toe Clamp. Three independent 360 degree rotating rubber pads firmly pinch almost any diameter and thickness bass drum counter hoop from the top and the bottom with zero slippage. Add to that a new textured rubber grip pad on the base plate and we think you\342\200\231ll agree that there\342\200\231s never been a better system for attaching a pedal to a bass drum. Last but certainly not least they wanted to improve on the smoothness and feel of the 5000 if that was even possible. To accomplish this DW added a Dual Bearing Spring Rocker making the 5000 quicker and more responsive. \020\015\015The Accelerator\342\204\242 (AD4) drive system offers an eccentric motion that creates an indirect relationship between the sprocket and the footboard increasing the velocity of the pedal by shortening the length of the stroke. It is recommended for situations that require increased speed and sensitivity. Featuring a host of refinements and upgrades the legendary line of 5000 Series bass drum pedals still features a choice of drive systems aluminum hex shafts pedal plates and linkages 101 two-way beater and built in spurs.