Pros and cons...
Siping is named after John Sipes, a meat factory worker, who found that his rubber boots were slipping on the blood and gores in the meat packing slaughter house. He found that cutting slits on the tread with a razor gave him better tractions and reduced slipping.
Traction comes from basically two forms: the contact patch between the tread surface and the road surface. This contact friction depends on the roughness of the road surface, the compound in the tread, the saize of the contact patch. The greater the surface patch, the greater the traction. The softer the tread compound, the better the traction, but increased wear. harder compounds last longer, but decrease traction.
The tread is divided into "lands" and "voids"; lands are the tread blocks and hte voids are the open spaces. Mud and true all terrain tires have more voids or larger void spaces for the dirt and irregalur surfaces or snow or muck to get into and grabbed by the lands. However, in snow or rain, voids may not work as well so sipes are added in the tire construction.
Notice that snow tires like the Blizzak have thousands of sipes? they act as squeegees to flush the water out form the lands and create more "edges" to bite into the road surface. In snow, they hold more snow and snow sticks to snow to grip better. So yes, sipes do work.
Aftermarket cutting works best for mud terraiin tires where you want sipes to increase traction as most mudders don't have any sipes. But the question is how would those aftermarket siping work? Sipes come in many sizes. Some are more open and in true snow tires are open to let snow in to stick and grip. Razor tight sipes aren't going to open like factory sipes.
Aftermarket sipes are done on a siping machine that cuts many. many razor thin lines across the tread. Factory sipes are computer desgined to be self supporting, of varying sizes, and designed to be within the tread block to reduce "chunking" or tearing. Aftermaket sipes just cut right across the tread regardless sof the siping and tread block patter, causing the tread to be cut nilly-willy, literally chopping the tread block like a meat tenderizer. Of course the tires feel they ride smoother. The tires jsut went through a meat tenderizer! The tread blocks were tenderized and softened!
Just look at the tread blocks after a siping machine has done chopping it up. You will fine the read wiht cuts going cross factory sipes, sipes cutting small portions into smaller portions, decreasing the tread block strength, increasing the "chunking" as the tread block is more prone to squirming and twisting and finally heating and tearing. Notice that high performance tires use almost no siping? That's to reduce the twisting by keeping maximum strength of the tread blocks.
So the question is how much better traction can cutting the tire nilly willy give you over the compute desinged tread blocks in the Revo? Every tire is a compromise of tread wear, tracton over a wide variety of surfaces, performance, and cost. Million dollar computers and tire design engineers have worked a long time testing every tread compound and pattern. They know what they are doing. Tire stores want to make another $20/tire off you. I just don't think aftermaket siping increases traction to where I would trade off the negatives.
Just my humble opinion.
: He's one of the bestest writers this joint has.
