User guide
E-scooter wheel engineering: BS EN ISO 4210-7:2014 wheels (39.7 J drop-ball impact + 640 N static + dynamic), BS EN ISO 4210-2:2023 § 4.10 wheel/tire assembly, ASTM F2641-23 § 8 PMD wheels-and-tires, ETRTO 2024 rim-side (BSD 305 / 349 / 406 / 451 / 507 / 559 / 622 mm), ISO 5775-2:2015 rim designation, rim materials (extruded 6061-T6 / 6082-T6 σ_y 276 MPa vs cast A356-T6/AlSi7Mg 205 MPa vs forged 7075-T6 503 MPa vs PU-foam tubeless vs CFRP T700S), wheel topology (laced 32/36-spoke cross-3 vs cast 5/6/10/12-spoke molded vs solid PU), spoke materials (304 stainless 14g/2.0 mm vs DT Swiss Aerolite ⌀ 2.34×0.9 mm bladed vs Sapim CX-Ray), spoke-tension (Park Tool TM-1 80-130 kgf drive-side, drive/non-drive ratio asymmetry 60:40), wheel-truing tolerance (radial / lateral ±0.5 mm per ISO 4210-7 § 4.10), rim profile (box-section vs single-wall vs double-wall vs aero V-shape, ERD effective-rim-diameter), lacing math (L = √(d² + r² + R² − 2rR·cos(α·k·π/n)) − ⌀h/2 Brandt 1981), failure modes (spoke elbow fatigue / rim crack at spoke-hole / hub-flange crack / cast hairline / PU-foam hardening / bead-seat damage), Hub-motor specifics (BLDC stator embedded, 36-spoke common, rim heat-sink), CPSC recall context (Xiaomi M365 2019, Hover-1/Razor cast-wheel cracks), DIY check / DIY remediation
Engineering deep-dive into the e-scooter wheel unit — rim profile + spokes/cast structure + lacing + wheel-build — paralleling other engineering-axis articles on [tires as the rubber-side interaction](@/guide/tire-engineering-rolling-resistance-grip-standards.md), [bearings as the hub-bearings axis](@/guide/bearing-engineering-iso-281-l10-life.md), and the [frame](@/guide/frame-and-fork-engineering.md). The wheel is an assembly-level engineering axis that integrates rim (profile + material) + spokes (lacing + tension) + hub (bearings, DJ-axis) + tire (DH-axis) into a single load-bearing structure. Covers: 10-row safety-standards matrix (BS EN ISO 4210-7:2014 wheels, BS EN ISO 4210-2:2023 § 4.10 wheel/tire assembly, BS EN ISO 4210-9:2014 hub bolt-axle/QR, ASTM F2641-23 § 8 PMD wheels-and-tires, ETRTO 2024 rim-side, ISO 5775-2:2015 rim designation, EN 14764:2005 § 4.6 wheels and tires, JIS D 9402 bicycle wheel test); 7-row ETRTO BSD table (305 mm 16″ children / 349 mm 16″ Brompton-style folding / 406 mm 20″ BMX-style / 451 mm 20″ road-style / 507 mm 24″ MTB / 559 mm 26″ MTB / 622 mm 700C road); 8-row materials matrix (extruded 6061-T6 / extruded 6082-T6 / cast A356-T6 / cast AlSi7Mg / forged 7075-T6 / PU-foam tubeless / CFRP T700S / 4130 chromoly steel — with σ_y, σ_t, E, ρ, σ_y/ρ, manufacturability); 5-row spoke materials (304 stainless 14g/2.0 mm / 14-15g butted / DT Swiss Aerolite bladed / Sapim CX-Ray / titanium grade 5); 6-row failure-diagnostic matrix; 8-step DIY check + 6-step DIY remediation; 17 numbered sections from anatomy (8 components) → wheel topology (3 types) → rim profile (4 types) → ERD effective-rim-diameter + lacing math (Brandt formula) → spoke-tension (Park Tool TM-1 chart) → wheel-impact test rig (BS EN ISO 4210-7 § 4.2 drop ball 22.5 kg × 180 mm = 39.7 J) → static load (640 N) → truing tolerance (±0.5 mm) → hub-motor specifics → CPSC recall corpus (Xiaomi M365 wheel-bearing 2019, Hover-1/Razor cast-wheel hairline cracks) → DIY check/remediation + 8-point recap.