# The Weight of Chrome

## What It Physically Feels Like to Carry Augmentations

A standard cybernetic arm — the Sunder Dynamics Model 7, the most common augmentation in the Shelf — weighs 8.2 kilograms. A biological human arm weighs approximately 5 kilograms. The difference is 3.2 kilograms, which sounds manageable until you realize that you carry it every second of every day, that it hangs from a shoulder joint that evolved for a lighter load, and that the weight is distributed differently — concentrated in the forearm and hand where the actuators and power cell live, rather than spread across the organic gradients of muscle, bone, and fluid that a biological arm uses to distribute its mass.

Your posture changes. This is the first thing every augmentation recipient learns, usually in the physical therapy sessions that follow installation and usually with surprise. The body is a counterbalance system — every mass on one side requires a compensating shift on the other. A heavier left arm means the spine curves slightly right. The right shoulder rises to compensate. The gait shifts, the leading leg changes, the hips rotate a few degrees off their pre-augmentation axis. Physical therapists call this "chrome drift," and they can diagnose the type and vintage of an augmentation by the posture distortions it produces. A Sunder Model 7 produces a characteristic right-lean of 2.3 degrees. A Tessera limb, lighter by a kilogram, produces 1.7. A full bilateral replacement — both arms chrome — produces something else entirely: a forward lean, a lowered center of gravity, a walk that is subtly mechanical because the body's upper half now has a weight profile that human legs did not evolve to carry.

Phantom sensation persists in 73% of augmentation recipients, according to the most recent GLMZ Health Governance Board survey. The flesh that was removed continues to exist in the brain's body map, sending signals that the absent limb is still there — lighter, warmer, more flexible than the chrome that replaced it. The brain resolves this conflict differently in different people. Some experience the phantom as a ghost overlaid on the chrome — they feel both the absent flesh hand and the present chrome hand simultaneously, occupying the same space, one real and one remembered. Others experience alternation: moments when the arm feels like chrome, moments when it feels like flesh, the brain toggling between two incompatible maps of the same body part. The transition between states is disorienting. You reach for a cup and your hand is suddenly lighter than expected, or heavier, the coffee sloshing or the grip overcalibrating, because for a fraction of a second your brain forgot which arm you have.

Sleep with chrome is its own discipline. A cybernetic arm does not relax. It does not soften with drowsiness. It lies beside you in bed with the same weight and rigidity it maintains during waking hours, a constant presence against the mattress or against your partner's body. Shelf beds sag on the augmented side. Partners learn to sleep on the biological side. The arm's power cell hums at a frequency just below hearing, a vibration transmitted through the mattress and into the bones of whoever shares the bed. Some partners find it soothing. Others never adjust. There is a support group in Block 12 — the Chrome Widows, they call themselves, and the name is only half a joke — for the partners of heavily augmented people who cannot sleep beside the weight, the warmth, and the inhuman stillness of a body that is part machine.

The psychological weight is harder to measure. Every augmented person in GLMZ carries an awareness that they are heavier than they should be — that the body they inhabit does not match the body they were born with, that they are a collaboration between flesh and engineering that neither side fully consents to. The chrome is useful. The chrome is necessary. The chrome replaced something that was damaged, or inadequate, or simply too fragile for the world it had to navigate. But it is heavy. Not just in kilograms. In the constant, low-grade cognitive effort of being a person who is also, partially, a machine — of calibrating grip strength for a handshake, of remembering which arm can punch through a wall and which arm will break, of looking at your own hand and seeing, in the chrome's reflection, a face that is still entirely flesh and wondering how long that will last.