The Lamson line uses a proprietary conical drag design. I have yet to have a problem with any of mine and they are the smoothest I have used.



http://waterworks-lamson.com/our-story/

From Lamson's site re: disc drag vs. their conical:

The first problem is associated with the disk shape itself. A typical approach is to use two disks (one stationary, one rotates). But the disks need to be large in order to have the surface area required to generate stopping power. Once a disk is large it cannot be sealed from the elements, and this exposure brings with it a long list of other problems.

To address this problem, we reshaped the traditional disk drag into two mated cones. By doing so, we are able to take advantage of a large surface area for torque, but we reduce the overall diameter of the system so it could be fitted into a sealed chamber. The male cone is precisely machined to mate with a female cone; the male rotates while the female remains stationary.

The male conical element is a polymer alloy with an extremely low co-efficient of friction, and the female element is a Teflon impregnated metallic surface. The male cone has a very low co-efficient of thermal conductivity, meaning it conducts heat very slowly. The female cone, which is part of the frame, conducts heat very quickly. Thus, when heat is product by friction it is “wicked” off the male cone and out through the frame. The polymer alloy and Teflon/metal cones run without any oil or grease; thus no maintenance is required to keep the drag system performing at it’s best. And because the drag parts require no lubrication, don’t wear, and are fully sealed, the fisherman will never experience a change in performance and will never be burdened with cleaning, lubricating or maintaining the drag in any way.