The original System 1 from MRP set a benchmark for chain guide performance and was granted a USA patent that still stands. Over the years, the classic “Dual-Roller” design from MRP was refined for greater adjustability, frame compatibility, lower weight, and lower price, as seen with the System 2 and then the System 3 guides. The Dual-Roller design is a timeless, perfect mechanism that was deserving of an update. MRP started with a clean sheet of white paper and redesigned every single part to be lighter and easier to install and set up. The S4 Alloy will be the best fitting chain guide in the history of MRP and the world.
What makes the S4 Alloy distinct from the G2 SL is two things: • the backplate has a few more millimeters of frame clearance on the lower guide area compared to the G2 SL, which is necessary on some hard-to-fit frames • it uses a full bash guard so that impacts are transferred to the cranks and not the frame. Some riders prefer a full-bashguard system for this consideration, or for reasons of style.
The S4 Alloy will feature new bashguard designs, similar to the Party Crasher Lite, but even lighter. The same skeleton pattern of weight reduction on the new G2 SL skid plate is seen on the front side of the S4 Bashguard, while the back side of the S4 Bashguard features a honeycomb weight reduction pattern.