High performance Sram Rock Shox Pike Suspension Oil 0W-30 is all you should put in your Rock Shox Pike fork. This custom racing formula is exactly what the pros use.
The Pike, like most high-end forks these days—is a highly evolved piece of componentry. Motocross forks have nothing over mountain biking's most advanced offerings. It would be silly, almost criminal, and definitely negligent, to use anything but the highest-grade lubricants in such forks. Rock Shox's multi-grade oil will perform better in a wider range of conditions, last longer, and protect your investment more than any other. With a multi-grade rating, the 0W-30 will maintain consistent performance in your Pike from the bottom of the hill to the top, and back down again.