Spoke tension calculator
Tension a wheel with whatever tensiometer you own, not only Park Tool. Pick your tool and your spoke type/model, enter each reading, and balance the wheel using the live radar, the per-spoke status, and the centering guidance.
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Conversion table · Steel round 1.4 mm (dial reading 8-20)
| dial reading | kgf | N |
|---|---|---|
| 8 | 54 | 530 |
| 9 | 58 | 569 |
| 10 | 63 | 618 |
| 11 | 69 | 677 |
| 12 | 75 | 735 |
| 13 | 83 | 814 |
| 14 | 91 | 892 |
| 15 | 100 | 981 |
| 16 | 111 | 1089 |
| 17 | 123 | 1206 |
| 18 | 137 | 1344 |
| 19 | 154 | 1510 |
| 20 | 172 | 1687 |
Linear interpolation between points · readings outside 8 to 20 are not extrapolated.
These are estimates: devices drift and brands differ. Cap the reference side (the higher-tension one) at the rim maker's limit. Symmetric wheel (e.g. a rim-brake front) → other side 100%. Dished wheel → set the other side below 100% (≈55% road rear) or an absolute kgf, so each side judges against its real target. Reference side = the higher-tension side (drive on a rear, rotor side on a disc front).
How a reading becomes kgf
A tensiometer doesn't read tension directly: it reads deflection, and each device × spoke pair has its own published conversion table. The calculator interpolates within that table and never extrapolates beyond it — an out-of-range reading is flagged, not guessed. Every conversion carries the source and version of the table it came from. The figures are estimates: devices drift and rims differ, so treat them as a guide and re-measure as you build.
FAQ
- What tension should I aim for?
- The rim sets the ceiling: use the rim maker's published maximum for the reference side (the higher-tension one) — commonly in the 100–130 kgf range — and never exceed it. The other side isn't chosen; the dish fixes it. Set it as a percentage of the reference (≈55% on a typical road rear) or as a specific kgf.
- Which side is the reference side?
- The higher-tension one: the drive side on a rear wheel, the rotor side on a disc front. It has less centre-to-flange and a smaller bracing angle, so it needs more tension to hold the rim centred. A rim-brake front has no reference side: it's symmetric, so both sides share the same target (other side at 100%).
- How even does tension need to be?
- Evenness matters as much as the average: an even wheel is a wheel that stays true. Aim for a tight spread around each side's mean — the radar and the per-spoke status point out the outliers, and the tuning plan tells you which nipples to turn, a quarter turn at a time.
- My tensiometer isn't a Park Tool. Can I use it?
- That's the point of this tool. It ships conversion tables for Park Tool TM-1, DT Swiss Tensio 2, Unior, Super B, Wheel Fanatyk, Hozan, Birzman and more, each with its source listed. Missing yours? Tell me and I'll add it.