Wheelwright: Spoke & Tension

Per-side spoke lengths with borderline flags, geometry-derived tension targets on your own meter's curve, and a permanent record for every wheel. Offline. No account.

Parts ordered, spokes not yet cut. The ERD printed on the rim box and the ERD Marcus just measured with two spare spokes disagree by 2 mm - and a 2 mm spoke error is stripped nipples or poke-through. Down in the basement with one bar of signal, the web calculator won't load. Marcus needs a tool that lives where the work happens.

Wheelwright is the wheelbuilder's bench tool: exact spoke lengths, geometry-derived tension targets on your own meter's curve, and a permanent record for every wheel - fully offline, no account, nothing to log into.

WHAT IT DOES

• Spoke length engine: per-side inputs (ERD, flange PCD, center-to-flange, hole count, cross, spoke-hole diameter, rim offset, adjustments). Results to 0.1 mm with stocked-size rounding and a borderline flag when the raw length sits on a size boundary - so you verify the ERD before you cut. Bracing angles and the drive/non-drive tension ratio come out alongside.
• Every number shows its work: tap any result for the exact formula and inputs.
• Measurement helpers: guided two-spoke ERD and chord-method PCD flows do the arithmetic and draw the diagram. Your measured value overrides any saved or entered value and wears a "measured" badge.
• Tension sessions: enter readings spoke-by-spoke on big bench-friendly steppers, watch the radar chart tighten over each round, and save a snapshot from round one to final. Per-side mean, spread, and balance are computed for you.
• Your tensiometer, your curve: transcribe your own meter's reading-to-kgf card once. Wheelwright interpolates - and refuses to guess beyond the range you calibrated. Any analog or digital tool; direct-kgf entry for digital meters.

FREE, AND USEFUL FOREVER

Unlimited manual-entry calculations with full formula transparency, both measurement helpers, 2 builds, 1 tool profile, and 1 tension snapshot per build. A careful hobbyist can build wheel after wheel here.

PRO

• Component library - save your own hubs and rims from a caliper measurement or a manufacturer spec, with measured-override, and reuse them across builds so you never re-type a hub's geometry.
• Unlimited builds - a permanent, frozen record of every wheel, each with a searchable customer tag (free keeps 2).
• Tension history and compare - keep every session snapshot and overlay before/after to prove the balance (free keeps 1 per build).
• Build sheet PDF - a customer spec card with components, lengths, pattern, and the final tension radar.
• Multiple tool profiles - a calibration curve for every tensiometer on the bench (free keeps 1).
• Home Screen widgets - last-build quick-open and wheels built this year.

HONESTY, BY DESIGN

We built Wheelwright to agree with the workshop rule that the caliper outranks the catalog. It bundles no component database - the hubs and rims are the ones you save, and your measurement always wins. Borderline lengths are always flagged, radial lacing on a disc or drive flange always warns. It is a reference tool: verify critical dimensions by measurement before cutting spokes. No wheel-strength, safety, or warranty is certified.

Your builds live on this iPhone, in your hands. No account to make. Designed exclusively for iPhone.

PRICING

Lifetime: $49.99 one-time - own it. Annual: $19.99/year with a 30-day free trial. Monthly: $2.99/month. One purchase unlocks every Pro feature. Restore is always available.

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