Those claims have been solidified in the form of a recently granted patent, which details several different ways of executing the design, along with the resulting anti-squat, anti-rise, and leverage ratio numbers. Interestingly, the frame used in the patent descriptions has 172 millimeters of travel, and is shown with a water bottle in some of the images. I wouldn’t be surprised if this suspension layout shows up on the new Enduro – after all, it’s been over four years since that bike last received an update. It’s stood the test of time very well, and the geometry isn’t that far off from bikes that have been released this year, but there are undoubtedly some areas that could be revised.
The basic claim of the patent is that the system allows for greater flexibility when it comes to tuning individual aspects of the bike’s suspension performance. The drawings show in detail how the system functions – a link runs under the bike’s bottom bracket, connecting the chainstay to another short link that pivots around a bearing and drives the shock.
One interesting part of the patent is the section that mentions ‘field adjustable suspension.’ Several of Specialized’s mountain bikes have adjustable geometry, but this would add another level of customization. The example used mentions having multiple attachment points on the seat tube for the link that runs from the seatstay to the seat tube (labeled 74 in the photo). The patent states, “This could allow a rider of the bicycle to tune certain performance characteristics, such as anti-rise, to a particular terrain or course, without significantly or dramatically affecting certain other performance characteristics, such as leverage ratio and anti-squat.”
There patent also mentions using different brake mount designs to tune the bike’s anti-rise characteristics: “Changes can be made to the design of the brake mount and/or the rear braking system that attaches to the brake mount to cause the rear braking system to be positioned differently with respect to the seat stay member, but to still move or rotate with the seat stay member. These changes can result in adjustments to or tuning of the anti-rise characteristics of the suspension system.”
As far as the overall suspension characteristics of the bike in the patent, predictability appears to be the goal here – there isn’t anything that stands out as being too wild, a trend we’ve seen lately with suspension layouts from various companies. Extreme S-shaped leverage ratio curves are mostly a thing of the past, with smooth, moderate progression the new goal. The different configurations shown in the patent give the bike between 10% – 20% progression depending on the layout, and it mentions the ability to run either a coil or air shock.
A final interesting tidbit has to do with the frame construction details that the patent describes. The patent states, “Preferably, the main frame is constructed of individual components, as described above, which are fabricated from a metal material, such as aluminum or steel, and welded together. Desirably, the bottom bracket support member is created from a metal material by a forging process and, thus, benefits from the strength and durability advantages that inherently result from the forging process.”
It does go on to mention that “alternative materials such as composites may also be used in whole or in part to construct the main frame.” I’d be very surprised if there wasn’t a carbon version of this bike (assuming it becomes a real thing), but I also like imagining the mountain bike world’s reaction if the new Enduro was made of steeel.
We’ll see if this ends up being the next generation of the Enduro, or if Specialized decides to take another route entirely.
