Regardless of what science dictates...

[ubtripn]

My new brake drums with new shoes and new wheel cylinders stop AWESOME on ice and snow. We recently had some snow pack on our back street so I decided to find the limits. I slammed on the brakes at various speeds. I had already resigned myself to assuming that my C10 2 wheel drive would not do well on such surfaces. BUT IT STOPS FAST. I was amazed at the control and short distances. I also have new all season, standard sized tires on her but I was still blown away. In this specific set of conditions I cannot see disk brakes doing any better. Anti-lock yes but not disc. On dry pavement I think discs are much better but maybe it is precisely because of the slightly slower rate at which brake shoes operate or the fact that there is more material working together, I don't know but whatever it is my brake shoes are rockin on snow and ice. No rearend swapping or anything. Just thought I would share because in dry conditions I drive my truck like I do a motorcycle with extra space and I was very surprised to see her perform like this.

[Longhorn 70]

Where the disc brakes really shine is going through deep water. My old drum brakes would not work, then try to work then GRAB. I can't wait to get the disc conversion done

[ubtripn]

I do think I will still convert for all around performance but I am glad I can drive her in the winter =)

[SS Tim]

For a driver front dics brakes are the way to go. Adding a booster is also a really good idea. Rear drums are fine for most needs.

[ubtripn]

Will the booster I have work for when I convert to discs on the front?

[68Stepbed]

The booster will be fine, but you will have to change the proportioning valve.

[skorpioskorpio]

The real advantages to disks are, as stated, the braking surfaces are vertical so they drain off water better, and they are more linear in their action. Drums tend to hit a point of expansion and then the shoes wedge them selves into the drum and they lock up. Also all automotive drum systems I've ever seen use one leading shoe and one trailing shoe, in other words one point of expansion and both shoes sharing a common fixed point.

Before they went to disk, motorcycles, particularly high performance motorcycles used double leading shoe drums where both shoes expanded into the drum at their leading edge and the fixed point of the shoes was 180 degrees opposite each other. This has somewhat better wet performance and is less prone to wedging, because hey suddenly locking up the brakes on a motorcycle is a bit more spectacular than it is in a car.

Anyway, the point is that a big enough drum with the same capability to arrest a given amount of inertia as a disk will not have the same linear application feel to it.

[PanelDeland]

The other advantage to disc is that they don't fade as badly in stop and go traffic.The surfaces are more open to air and cool quicker.

[skorpioskorpio]

Originally Posted by PanelDeland

The other advantage to disc is that they don't fade as badly in stop and go traffic.The surfaces are more open to air and cool quicker.

This, I think is more of a factor of design of a specific system than an overall statement. There have been a lot of disk systems that have really horrible fading problems in both automotive and motorcycle applications. When drums get hot from over use they can become very sticky where they are pretty much like a switch, nothing or locked, where disks can become worthless and don't grab at all, or warp. Disks require far more fluid pressure to work effectively and far more surface tension and can heat up to the point that they will not work regardless of pressure applied.

There is also the factor of rotating mass. Increasing the braking surface area of a disk more or less creates a fairly linear increase in braking capability, whereas increasing the size of drums has diminishing returns because each increment of increase of surface area also substantially increases the rotating mass.

[ubtripn]

I see, thank you, I feel a conversion coming this summer =)