Living Review durability forecast — modeled, not observed
What should soften first, and how confident we are
Assumptions: the Medium option, two adults totalling under about 400 lb, nightly use, a solid base or slats under 5.5 in apart, rotation every six months, and no liquid damage. Inputs are Bear’s September 2026 layer specification as NapLab reports it, the coil gauges, and the three durability views above. No long-term or compression test of any build is published, so this is a qualitative scenario, not a service-life figure, a probability, or a rating.
Modeled first change
The 2-inch, 1.5 PCF quilt foam at the top. It is the lightest and thickest foam in the stack, and quilt foam typically compresses first, which shows up as a softer, slightly lower sleeping surface under the shoulders and hips before any sag is measurable.
Modeled countermeasures
The two memory-foam layers beneath it are denser (2.5 and 3.0 PCF), and the 8-inch zoned coils with heavier-gauge wire carry the structural load, so deep body impressions are a later, less likely change. Rotation spreads wear. Ten years of non-prorated cover handles real sagging, but not the softening Bear excludes.
Uncertainty and update rule
Confidence is moderate on the direction and low on the timing. Sleep Foundation’s 8.0 pulls the outlook up; RTINGS’s 4.3 and NapLab’s density concern pull it down, and all three predate or do not identify the current build. We will revise this section if a lab tests the September 2026 build, if Bear changes the layer list again, or if consistent owner reports describe the change above at a specific age.