Bürokraten, editor, Administratoren
15.322
Bearbeitungen
Felge und Nabe messen, um Speichenlängen zu berechnen: Unterschied zwischen den Versionen
Felge und Nabe messen, um Speichenlängen zu berechnen (Quelltext anzeigen)
Version vom 22. Februar 2022, 13:33 Uhr
, 22. Februar 2022→Fehler und Ihre Effekte: Tabele hinzugefügt
(→Speichenlänge prüfen: übersetzt) |
(→Fehler und Ihre Effekte: Tabele hinzugefügt) |
||
| Zeile 244: | Zeile 244: | ||
Effect of measurement errors | Effect of measurement errors | ||
{| {{Prettytable|width=50%}} | |||
Rim circumference 1/6.28 (1/2π) This is the most accurate way to measure for diameter. | !Messfehler bei!!Speichenlänge wird um diesen Faktor abwichen!!Bemerkungen | ||
Rim diameter 1/2 Must be measured at several angles and averaged | |- | ||
Depth from measured rim radius (1/2 diameter) to spoke hole 1 This is a difference in radius and applies to each spoke. | |Rim circumference ||1/6.28 (1/2π) ||This is the most accurate way to measure for diameter. | ||
Hub flange spacing from centerline About 1/10 Error becomes worse for small wheels/large flanges. | |- | ||
Hub spoke hole circle diameter Usually small, but up to 1/2 Small for high cross numbers, 1/2 for radial spoking. | |Rim diameter ||1/2 ||Must be measured at several angles and averaged | ||
Spoke hole diameter 1/2 Unimportant because spoke hole clearance is small. | |- | ||
Tensioning compensation -- Spokes will be effectively about 1mm longer when tensioned. | |Depth from measured rim radius (1/2 diameter) to spoke hole ||1 ||This is a difference in radius and applies to each spoke. | ||
|- | |||
|Hub flange spacing from centerline ||About 1/10 ||Error becomes worse for small wheels/large flanges. | |||
|- | |||
|Hub spoke hole circle diameter ||Usually small, but up to 1/2 ||Small for high cross numbers, 1/2 for radial spoking. | |||
|- | |||
|Spoke hole diameter ||1/2 ||Unimportant because spoke hole clearance is small. | |||
|- | |||
|Tensioning compensation ||-- ||Spokes will be effectively about 1mm longer when tensioned. | |||
|} | |||
For typical wheels, random errors dominate, but for larger wheels, and particularly, very large wheels such as on antique high-wheeler bicycles, proportional errors -- from the scale of a measuring tape being slightly to large or small, and from spoke stretch under tension -- become important. | For typical wheels, random errors dominate, but for larger wheels, and particularly, very large wheels such as on antique high-wheeler bicycles, proportional errors -- from the scale of a measuring tape being slightly to large or small, and from spoke stretch under tension -- become important. | ||
| Zeile 258: | Zeile 266: | ||
The range of spoke lengths which avoids these problems is about 3mm. The tolerance has become smaller in recent years, because short spoke nipples and matching short threads are fashionable to reduce aerodynamic drag. | The range of spoke lengths which avoids these problems is about 3mm. The tolerance has become smaller in recent years, because short spoke nipples and matching short threads are fashionable to reduce aerodynamic drag. | ||
===Falls Speichen zu kurz sind oder scheinen=== | ===Falls Speichen zu kurz sind oder scheinen=== | ||