Scope: "Gym Benches, Racks & Machines" bundles three product types experts judge differently — benches (flat/FID/adjustable), racks & cages (squat stand, half rack, power rack, wall-mounted), and machines (cable/functional trainer, Smith machine, multi-station selectorized) — split by `equipment_type`, each with its own facet set.

Seed:
1. Tyre-equivalent here is hole/pin diameter (5/8in vs 1in): every rack listing can carry it, but like treadwear it only compares within one rack's own attachment ecosystem, not across brands, and needs a judgement attached (does it fit the accessories you already own).
2. The tailor persona (fit, drape, what you can alter afterwards) would check hole spacing granularity and back-pad angle count first — literally "does this fit your body's bar path" — and hole/pin diameter second, since that is "what you can alter afterwards" without buying a new frame.

Sources:
[astm_f3105] https://store.astm.org/f3105-20.html — governing US spec for benches/plate-loaded equipment — fetched title/scope: "Standard Specification for Externally Loaded Strength Training Equipment, Strength Training Benches and External Weight Storage Equipment"
[astm_f2216] https://store.astm.org/f2216-17a.html — governing US spec for selectorized machines — fetched title: "Standard Specification for Selectorized Strength Equipment"
[en957_celectronics] https://www.celectronics.com/product-safety-testing/EN-957 — EN 957-2 strength equipment, Class H/S — fetched: "Strength training equipment (EN 957-2)... Class H - Home use... Class S - Studio/professional use"
[skelcore_astm] https://www.skelcore.com/guides/what-astm-standards-safety-fitness-equipment — corroborates F3105 scope — fetched: "ASTMF3105 covers externally loaded strength training gear—like benches and free-weight stations"
[lazada_rack_specs] https://sports.lazada.com.ph/power-rack-gym-equipment-specs-what-steel-gauge-weight-capacity-and-hole-spacing-mean-ph/ — gauge mm + static/dynamic + hole spacing — fetched: "11-gauge steel is approximately 3 millimeters thick, whereas 14-gauge steel is only about 2 millimeters thick"; "Standard spacing is typically 2 inches apart"
[fringesport_capacity] https://www.fringesport.com/blogs/news/how-much-weight-can-a-power-rack-hold — capacity ranges + gauge terms — fetched: "weight capacity of most power racks ranges from 500 lbs to 1500 lbs"; "highest quality power racks typically use 11-gauge steel"
[titan_t3_megamenu] https://titan.fitness/products/t-3-series-power-rack — upright size/gauge — fetched: "Larger 2”x3” uprights, thicker 11-gauge steel"; "3” x 3” uprights and 11-gauge steel"
[vervefitness_westside] https://www.vervefitness.com.au/blogs/all/what-is-westside-hole-spacing-and-why-it-matters — Westside spacing numbers — fetched: "holes every 25mm (1 inch) in the bench press zone and every 50mm (2 inches)... elsewhere"
[ritfit_hole_diameter] https://www.ritfitsports.com/blogs/article/58-vs-1-inch-power — diameter vs spacing distinction — fetched: "the 5/8 inch and 1 inch figures describe diameter rather than spacing"
[titan_rack_types_guide] https://titan.fitness/blogs/equipment-guides/squat-stands-vs-power-racks — rack subtype definitions — fetched: "Squat Stand: Two uprights, no connecting frame"; "Half Rack: Four uprights like a power rack, but... train outside the frame"
[rep_ab3000_bench] https://repfitness.com/products/ab-3000-fid-adjustable-bench — bench capacity/positions — fetched: "weight capacity of 1,000lbs"; "Eight back and five seat positions"
[titan_fid_bench] https://titan.fitness/products/single-post-adjustable-fid-bench — bench capacity/positions — fetched: "1,000 LB flat weight capacity and 500 LB incline rating"; "Four seat pad positions and six back pad angles (from 0-85 degrees)"
[prime_functional_trainer] https://primestrengthco.com/blogs/gym-equipment-guides/functional-trainer-vs-cable-machine-ultimate-guide — pulley ratio — fetched: "most trainers use 2:1... crossovers typically run 1:1"
[ritfit_smith_vs_ft] https://www.ritfitsports.com/blogs/article/smith-machine-vs-functional-trainer — frame capacity concept — fetched: "that same frame is rated for 2,200 lb of structural load"
[stronghomegym_smith] https://stronghomegym.com/best-smith-machine/ — counterbalance — fetched: "A counterbalance offsets the bar's weight, so the Pro ClubLine bar starts at 6 lb"

Branches:
- equipment_type=bench → bench_adjustability, back_pad_adjustment_positions, bench_weight_capacity; irrelevant: hole spacing/pin diameter, cable/smith/stack facets. Supported by rep_ab3000_bench and titan_fid_bench both selling the bench spec set as a unit distinct from rack specs.
- equipment_type=rack_or_cage → rack_footprint_class, hole_spacing_pattern, safety_mechanism_type. Supported by titan_rack_types_guide's own three-way subtype split (stand/half/full).
- equipment_type=cable_machine_or_functional_trainer / multi_station_home_gym → cable_pulley_ratio, weight_stack_max. Supported by prime_functional_trainer treating ratio and stack as the defining spec pair.
- equipment_type=smith_machine → smith_bar_counterbalance, safety_mechanism_type. Supported by stronghomegym_smith distinguishing counterbalanced vs non-counterbalanced as the core buying question.
- solo_training_safety_need=trains_alone → safety_mechanism_type, rack_footprint_class become higher priority. Supported by titan_rack_types_guide: "Buy a power rack if you train heavy alone."

Noise (spec-sheet rows left out):
- Bench/rack color options (many SKUs, cosmetic only, not an expert judgement axis).
- Warranty length — varies by retailer/region, not a product spec an expert compares category-wide.
- Assembly time/tool count — real but minor; not load-bearing to the buying decision.
- Shipping weight vs rated capacity — shipping weight is a logistics fact, not a performance spec.
- Exact rack footprint in sq ft — WebSearch summaries cited 8x8ft/4x8ft figures but the fetched Titan guide page did not contain those numbers in retrievable text, so dropped rather than invented; kept the qualitative subtype ordering (stand < half rack < full cage) instead, which was directly confirmed.
- Number of exercise stations on multi-station gyms — no two-source numeric range could be confirmed this run; left out rather than guessed.

Corrections (2026-10-26):
- weight_stack_max: dropped the 100-300 lb range (its only source, prime_functional_trainer, contains no lb figures); kept the facet qualitative, single-sourced, no invented default.
- equipment_type: split cable_machine_or_functional_trainer into functional_trainer and cable_crossover_station so cable_pulley_ratio's 2:1/1:1 default keys to an explicit value; added both to vocabulary.
- equipment_type branches: added bench_weight_capacity and back_pad_adjustment_positions to makes_irrelevant on rack_or_cage, functional_trainer, cable_crossover_station, smith_machine, multi_station_home_gym; added weight_stack_max to smith_machine's makes_irrelevant.
- Added facets band_peg_chain_accommodation and floor_anchoring_capability, cited to titan_rack_types_guide's FAQ (single-sourced — no second source found this pass); wired into rack_or_cage then_ask and every other branch's makes_irrelevant; added vocabulary for both.
- equipment_type cold_start_question/split question reworded to "Bench, rack, cable or Smith machine, or all-in-one gym?" so multi_station_home_gym is an answerable option.
- bench_weight_capacity: lowered range max from 1500 to 1000 lb, the figure both cited sources actually state; 1500 was uncited.
- Added a no-op-adjacent branch for solo_training_safety_need=trains_with_spotter_or_partner (makes_irrelevant: floor_anchoring_capability) so the split isn't half-built.
- Defined lever_arm in vocabulary, matching pin-and-pipe/pop-pin treatment.
- back_pad_adjustment_positions: reclassified source from listing to researched; both confirmations are brand pages, not representative marketplace listings.
- rack_static_load_capacity: dropped the 2200 lb max (sourced only to a Smith-machine frame rating in ritfit_smith_vs_ft, now removed from references entirely as unused); re-sourced range to fringesport_capacity alone (300-1500 lb, both figures stated in its fetched text).