{"id":3352,"date":"2026-05-14T05:13:35","date_gmt":"2026-05-14T05:13:35","guid":{"rendered":"https:\/\/sprocket-chain.net\/?p=3352"},"modified":"2026-05-14T05:13:35","modified_gmt":"2026-05-14T05:13:35","slug":"motorcycle-chain-sprocket-selection-sizing-and-replacement-guide","status":"publish","type":"post","link":"https:\/\/sprocket-chain.net\/cs\/motorcycle-chain-sprocket-selection-sizing-and-replacement-guide\/","title":{"rendered":"\u0158et\u011bz a pastorek pro motocykly: Pr\u016fvodce v\u00fdb\u011brem, dimenzov\u00e1n\u00edm a v\u00fdm\u011bnou"},"content":{"rendered":"
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\u0158et\u011bzy pro motorsport a pohon<\/span><\/p>\n<\/div>\n

\u0158et\u011bz a pastorek pro motocykly: Pr\u016fvodce v\u00fdb\u011brem, dimenzov\u00e1n\u00edm a v\u00fdm\u011bnou<\/h1>\n

Po\u010det zub\u016f p\u0159edn\u00edho \u0159et\u011bzov\u00e9ho kola m\u00e1 v\u011bt\u0161\u00ed vliv na m\u00edru opot\u0159eben\u00ed \u0159et\u011bzu motocyklu ne\u017e jak\u00e1koli jin\u00e1 jednotliv\u00e1 prom\u011bnn\u00e1 \u2013 v\u010detn\u011b kvality \u0159et\u011bzu. V\u011bt\u0161ina jezdc\u016f, kte\u0159\u00ed m\u011bn\u00ed p\u0159edn\u00ed \u0159et\u011bzov\u00e9 kolo za \u00fa\u010delem zv\u00fd\u0161en\u00ed to\u010div\u00e9ho momentu, nev\u011bdomky obchoduje s \u017eivotnost\u00ed \u0159et\u011bzu za cenu, kterou by v\u011bt\u0161ina z nich odm\u00edtla, kdyby rozum\u011bli aritmetice.<\/p>\n

Po\u0159i\u010fte si pro sv\u016fj motocykl vhodn\u00e9 ozuben\u00e9 kolo a \u0159et\u011bz<\/a><\/p>\n<\/div>\n<\/div>\n<\/div>\n

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Korejsk\u00fd z\u00e1vodn\u00edk na okruhu p\u0159estav\u011bl sv\u016fj supersport o objemu 600 ccm v\u00fdm\u011bnou p\u0159edn\u00edho pastorku z 15 zub\u016f na 14 zub\u016f \u2013 redukce o jeden zub, kter\u00e1 je na internetu \u0161iroce doporu\u010dov\u00e1na pro lep\u0161\u00ed to\u010div\u00fd moment p\u0159i v\u00fdjezdu z zat\u00e1\u010dky. Po 4 000 km se jeho zadn\u00ed pastorek viditeln\u011b zah\u00e1kl a \u0159et\u011bz se prodlou\u017eil za hranici se\u0159izovac\u00edho mechanismu. Jeho p\u0159edchoz\u00ed s\u00e9riov\u00e9 nastaven\u00ed vydr\u017eelo p\u0159i stejn\u00e9m pou\u017e\u00edv\u00e1n\u00ed 12 000 km. Redukce zub\u016f nezp\u016fsobila katastrofick\u00e9 selh\u00e1n\u00ed \u0159et\u011bzu \u2013 pouze zv\u00fd\u0161ila m\u00edru opot\u0159eben\u00ed \u0159et\u011bzu faktorem t\u0159i, co\u017e je p\u0159edv\u00eddateln\u00fd v\u00fdsledek, kter\u00fd p\u0159\u00edmo vypl\u00fdv\u00e1 z geometrie toho, jak se hnac\u00ed \u0159et\u011bz dot\u00fdk\u00e1 p\u0159edn\u00edho pastorku p\u0159i r\u016fzn\u00e9m po\u010dtu zub\u016f. Fyzika tohoto vztahu je m\u00e9n\u011b intuitivn\u00ed, ne\u017e nazna\u010duje v\u011bt\u0161ina p\u0159\u00edru\u010dek pro \u00fadr\u017ebu motocyklu, a spr\u00e1vn\u00e9 nastaven\u00ed pom\u011bru zub\u016f mezi p\u0159edn\u00ed a zadn\u00ed \u010d\u00e1st\u00ed je z\u00e1kladem spr\u00e1vn\u00e9 \u00fadr\u017eby. \u0159et\u011bz a pastorek motocyklu<\/strong> specifikace.<\/p>\n

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Nomenklatura rozte\u010de \u0159et\u011bzu motocykl\u016f: 420, 428, 520, 525, 530 a 630 dek\u00f3dov\u00e1no<\/h2>\n

Ozna\u010den\u00ed rozte\u010de \u0159et\u011bz\u016f motocykl\u016f matou ka\u017ed\u00e9ho nov\u00e9ho kupce, proto\u017ee se zd\u00e1, \u017ee se \u0159\u00edd\u00ed jinou logikou ne\u017e standardn\u00ed \u010d\u00edslov\u00e1n\u00ed \u0159et\u011bz\u016f ANSI nebo ISO. Neuv\u00e1d\u00ed p\u0159\u00edmo rozte\u010d v milimetrech ani v \u017e\u00e1dn\u00e9 jin\u00e9 jednotce. Trojm\u00edstn\u00fd k\u00f3d k\u00f3duje dva rozm\u011bry: rozte\u010d a vnit\u0159n\u00ed \u0161\u00ed\u0159ku, a to pomoc\u00ed k\u00f3dovac\u00edho syst\u00e9mu zd\u011bd\u011bn\u00e9ho z ran\u00e9 americk\u00e9 praxe pr\u016fmyslov\u00fdch \u0159et\u011bz\u016f.<\/p>\n

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Prvn\u00ed \u010d\u00edslice: v\u00fd\u0161ka t\u00f3nu<\/div>\n

V t\u0159\u00edm\u00edstn\u00fdch k\u00f3dech p\u0159edstavuje prvn\u00ed \u010d\u00edslice rozte\u010d v osmin\u00e1ch palce. \u201e5\u201c = 5\/8 palce = 15,875 mm. \u201e4\u201c = 4\/8 palce = 12,70 mm. \u201e6\u201c = 6\/8 palce = 19,05 mm. V \u010dty\u0159m\u00edstn\u00fdch k\u00f3dech p\u0159edstavuj\u00ed prvn\u00ed dv\u011b \u010d\u00edslice rozte\u010d v osmin\u00e1ch palce: \u201e25\u201c = 25\/8 palce. Proto maj\u00ed modely 520, 525 a 530 stejnou rozte\u010d 15,875 mm \u2013 li\u0161\u00ed se pouze vnit\u0159n\u00ed \u0161\u00ed\u0159kou.<\/p>\n<\/div>\n

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Posledn\u00ed dv\u011b \u010d\u00edslice: vnit\u0159n\u00ed \u0161\u00ed\u0159ka<\/div>\n

Posledn\u00ed dv\u011b \u010d\u00edslice p\u0159edstavuj\u00ed \u0161\u00ed\u0159ku vnit\u0159n\u00edho \u010dl\u00e1nku v 80tin\u00e1ch palce. \u201e20\u201c = 20\/80 palce = 6,35 mm. \u201e25\u201c = 25\/80 palce = 7,94 mm. \u201e30\u201c = 30\/80 palce = 9,53 mm. \u0158et\u011bz 530 m\u00e1 tedy rozte\u010d 15,875 mm a vnit\u0159n\u00ed \u0161\u00ed\u0159ku 9,53 mm \u2013 rozm\u011brov\u011b je shodn\u00fd s ANSI #50 a ozuben\u00e1 kola jsou technicky stejn\u00e1. \u0158et\u011bz 520 m\u00e1 stejnou rozte\u010d, ale u\u017e\u0161\u00ed \u0161\u00ed\u0159ku vnit\u0159n\u00edho \u010dl\u00e1nku ne\u017e ANSI #50.<\/p>\n<\/div>\n<\/div>\n

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Ozna\u010den\u00ed<\/th>\nRozte\u010d (mm)<\/th>\nVnit\u0159n\u00ed \u0161\u00ed\u0159ka (mm)<\/th>\nTypick\u00e1 aplikace<\/th>\nHmotnost\/metr (p\u0159ibli\u017en\u011b)<\/th>\n<\/tr>\n<\/thead>\n
420<\/td>\n12.70<\/td>\n6.35<\/td>\nMal\u00e9 motocykly (50\u2013150 ccm), pitbiky, mopedy<\/td>\n0,52 kg\/m\u00b2<\/td>\n<\/tr>\n
428<\/td>\n12.70<\/td>\n7.94<\/td>\nDoj\u00ed\u017ed\u011bj\u00edc\u00ed a ter\u00e9nn\u00ed kola o objemu 125\u2013250 ccm<\/td>\n0,65 kg\/m\u00b2<\/td>\n<\/tr>\n
520<\/td>\n15.875<\/td>\n6.35<\/td>\nSportovn\u00ed motocykly o objemu 250\u2013450 ccm, motokros, tra\u0165ov\u00e9 p\u0159estavby motocykl\u016f o objemu 600 ccm<\/td>\n0,80 kg\/m\u00b2<\/td>\n<\/tr>\n
525<\/td>\n15.875<\/td>\n7.94<\/td>\nSportovn\u00ed a sportovn\u011b-cestovn\u00ed motocykly o objemu 600\u2013750 ccm<\/td>\n0,92 kg\/m\u00b2<\/td>\n<\/tr>\n
530<\/td>\n15.875<\/td>\n9.53<\/td>\nSportovn\u00ed, nah\u00e9 a cestovn\u00ed motocykly o objemu 750\u20131000 ccm \u2013 standard OEM na mnoha platform\u00e1ch<\/td>\n1,10 kg\/m\u00b2<\/td>\n<\/tr>\n
630<\/td>\n19.05<\/td>\n9.53<\/td>\nT\u011b\u017ek\u00e9 cestovn\u00ed motocykly (1200\u20131800 ccm), cruisery, postrann\u00ed voz\u00edky<\/td>\n1,65 kg\/m\u00b2<\/td>\n<\/tr>\n<\/tbody>\n<\/table>\n<\/div>\n
Konverze 520 \u2013 zv\u00fd\u0161en\u00ed v\u00fdkonu, nebo fale\u0161n\u00e1 \u00faspora?<\/strong> Mont\u00e1\u017e \u0159et\u011bzu a sady pastorku s rozte\u010d\u00ed 520 na motocykl o objemu 600 ccm nebo 750 ccm, kter\u00fd p\u016fvodn\u011b pou\u017e\u00edval motor 530, sni\u017euje neodpru\u017eenou rotuj\u00edc\u00ed hmotu a sni\u017euje hmotnost \u0159et\u011bzu \u2013 co\u017e je skute\u010dn\u00e9 a m\u011b\u0159iteln\u00e9 zlep\u0161en\u00ed v\u00fdkonu na okruhov\u00e9m motocyklu. \u0158et\u011bz 520 m\u00e1 v\u0161ak u\u017e\u0161\u00ed vnit\u0159n\u00ed \u0161\u00ed\u0159ku \u010dl\u00e1nku a obvykle ni\u017e\u0161\u00ed minim\u00e1ln\u00ed pevnost v tahu ne\u017e 530 p\u0159i stejn\u00e9 kvalit\u011b. Pro silni\u010dn\u00ed pou\u017eit\u00ed se spolujezdcem, zavazadly nebo b\u011b\u017enou j\u00edzdu po d\u00e1lnici vy\u017eaduje p\u0159estavba na 520 u motocyklu s motorem o objemu 530 pr\u00e9miov\u00fd \u0159et\u011bz 520 s X-krou\u017eky nebo z\u00e1vodn\u00ed specifikaci, nikoli levn\u00fd 520 \u2013 \u00faspora na po\u0159izovac\u00edch n\u00e1kladech na \u0159et\u011bz se rychle ztr\u00e1c\u00ed ve prosp\u011bch vy\u0161\u0161\u00ed frekvence v\u00fdm\u011bn, pokud se standardn\u00ed \u0159et\u011bz 520 pou\u017eije v aplikaci, kterou p\u016fvodn\u00ed in\u017een\u00fd\u0159i pro 530 specifikovali kv\u016fli jeho z\u00e1t\u011b\u017eov\u00e9mu charakteru.<\/div>\n

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P\u0159evodov\u00fd pom\u011br a opot\u0159eben\u00ed \u0159et\u011bzu: Aritmetika, kterou v\u011bt\u0161ina jezdc\u016f p\u0159ehl\u00ed\u017e\u00ed<\/h2>\n
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Z\u00e1b\u011br hnac\u00edho \u0159et\u011bzu motocyklu na p\u0159edn\u00edm \u0159et\u011bzov\u00e9m kole \u2013 kontaktn\u00ed plocha v\u00e1le\u010dk\u016f a \u00fahel op\u00e1s\u00e1n\u00ed jsou kriticky z\u00e1visl\u00e9 na po\u010dtu zub\u016f p\u0159edn\u00edho \u0159et\u011bzov\u00e9ho kola.<\/p>\n<\/div>\n

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P\u0159edn\u00ed \u0159et\u011bzov\u00e9 kolo m\u00e1 ne\u00fam\u011brn\u00fd vliv na opot\u0159eben\u00ed \u0159et\u011bzu ze dvou na sob\u011b nez\u00e1visl\u00fdch d\u016fvod\u016f. Prvn\u00edm je polygonov\u00fd efekt: p\u0159i n\u00edzk\u00e9m po\u010dtu zub\u016f se rychlost \u0159et\u011bzu m\u011bn\u00ed sinusoid\u00e1ln\u011b p\u0159i ka\u017ed\u00e9 ot\u00e1\u010dce s amplitudou, kter\u00e1 se zvy\u0161uje s klesaj\u00edc\u00edm po\u010dtem zub\u016f. 14zub\u00e9 p\u0159edn\u00ed \u0159et\u011bzov\u00e9 kolo vytv\u00e1\u0159\u00ed zm\u011bnu rychlosti \u00b12,31 TP3T; 16zub\u00e9 vytv\u00e1\u0159\u00ed \u00b11,751 TP3T; 17zub\u00e9 (praktick\u00e9 minimum ANSI pro plynul\u00fd chod) vytv\u00e1\u0159\u00ed \u00b11,71 TP3T. Tyto hodnoty se zdaj\u00ed b\u00fdt bl\u00edzk\u00e9, ale efekt se zhor\u0161uje, proto\u017ee 14zub\u00e9 kolo b\u011b\u017e\u00ed tak\u00e9 p\u0159i vy\u0161\u0161\u00edch ot\u00e1\u010dk\u00e1ch p\u0159i dan\u00e9 rychlosti.<\/p>\n

Druh\u00fdm d\u016fvodem je \u00fahel op\u00e1s\u00e1n\u00ed. P\u0159edn\u00ed pastorek s men\u0161\u00edm po\u010dtem zub\u016f m\u00e1 men\u0161\u00ed pr\u016fm\u011br rozte\u010de. P\u0159i stejn\u00e9 vzd\u00e1lenosti od st\u0159edu k zadn\u00edmu pastorku (p\u0159ibli\u017en\u011b dan\u00e9 d\u00e9lkou kyvn\u00e9 vidlice) znamen\u00e1 men\u0161\u00ed p\u0159edn\u00ed pastorek men\u0161\u00ed \u00fahel op\u00e1s\u00e1n\u00ed \u2013 \u0159et\u011bz se dot\u00fdk\u00e1 men\u0161\u00edho po\u010dtu zub\u016f p\u0159edn\u00edho pastorku sou\u010dasn\u011b. S 15 zuby a 45 zuby vzadu m\u00e1 typick\u00fd supersport o objemu 600 ccm v kontaktu s p\u0159edn\u00edm pastorkem p\u0159ibli\u017en\u011b 6\u20137 zub\u016f. Se 14 zuby to kles\u00e1 na 5\u20136 zub\u016f. Ka\u017ed\u00fd zub nyn\u00ed nese proporcion\u00e1ln\u011b v\u011bt\u0161\u00ed \u010d\u00e1st celkov\u00e9ho nap\u011bt\u00ed \u0159et\u011bzu, co\u017e zvy\u0161uje kontaktn\u00ed nap\u011bt\u00ed a m\u00edru opot\u0159eben\u00ed zub\u016f.<\/p>\n<\/div>\n<\/div>\n

Vztah mezi po\u010dtem zub\u016f p\u0159edn\u00edho \u0159et\u011bzov\u00e9ho kola a napnut\u00edm \u0159et\u011bzu lze vyj\u00e1d\u0159it jako: Fc = 2T \u00d7 \u03c0 \/ (N \u00d7 p), kde T je to\u010div\u00fd moment motoru na p\u0159edlohov\u00e9m h\u0159\u00eddeli (Nm), N je po\u010det zub\u016f p\u0159edn\u00edho \u0159et\u011bzov\u00e9ho kola a p je rozte\u010d \u0159et\u011bzu (m). Pro motor o objemu 600 ccm, kter\u00fd produkuje maxim\u00e1ln\u00ed to\u010div\u00fd moment 65 Nm na p\u0159edlohov\u00e9m h\u0159\u00eddeli s p\u0159edn\u00edm \u0159et\u011bzov\u00fdm kolem 15T a rozte\u010d\u00ed 15,875 mm: Fc = 2 \u00d7 65 \u00d7 \u03c0 \/ (15 \u00d7 0,015875) = 408,4 \/ 0,238 = 1 716 N \u2013 p\u0159ibli\u017en\u011b 1,72 kN. P\u0159echod na pastorek 14T p\u0159i stejn\u00e9m to\u010div\u00e9m momentu: Fc = 2 \u00d7 65 \u00d7 \u03c0 \/ (14 \u00d7 0,015875) = 408,4 \/ 0,2223 = 1 837 N \u2013 p\u0159ibli\u017en\u011b 1,84 kN, co\u017e p\u0159edstavuje n\u00e1r\u016fst maxim\u00e1ln\u00edho nap\u011bt\u00ed \u0159et\u011bzu o 71 zub\u016f a 3 zuby p\u0159i v\u00fdm\u011bn\u011b jedin\u00e9ho zubu.<\/p>\n

Protiintuitivn\u011b: p\u0159edn\u00ed pastorek ovliv\u0148uje rychlost opot\u0159eben\u00ed \u0159et\u011bzu v\u00edce ne\u017e zadn\u00ed pastorek.<\/strong> Redukce o jeden zub na p\u0159edn\u00edm kole (14T \u2192 13T) zvy\u0161uje napnut\u00ed \u0159et\u011bzu o ~8% A SN\u00cd\u017d\u00cd po\u010det zub\u016f v kontaktu p\u0159ibli\u017en\u011b o jeden zub \u2013 oba efekty zvy\u0161uj\u00ed kontaktn\u00ed nap\u011bt\u00ed na zub. Ekvivalentn\u00ed zm\u011bna pom\u011bru proveden\u00e1 p\u0159id\u00e1n\u00edm jednoho zubu na zadn\u00edm kole (45T \u2192 49T) zvy\u0161uje napnut\u00ed \u0159et\u011bzu pouze o ~2% a ve skute\u010dnosti zvy\u0161uje po\u010det zub\u016f v kontaktu na p\u0159edn\u00edm \u0159et\u011bzov\u00e9m kole (proto\u017ee v\u011bt\u0161\u00ed pr\u016fm\u011br zadn\u00edho \u0159et\u011bzov\u00e9ho kola m\u00edrn\u011b zv\u011bt\u0161uje \u00fahel ovinut\u00ed \u0159et\u011bzu kolem p\u0159edn\u00edho kola). Pokud je nutn\u00e1 zm\u011bna pom\u011bru, je v t\u00e9m\u011b\u0159 v\u0161ech p\u0159\u00edpadech lep\u0161\u00ed strategi\u00ed opot\u0159eben\u00ed v\u00fdm\u011bna zadn\u00edch zub\u016f nam\u00edsto p\u0159edn\u00edch.<\/div>\n

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Standardn\u00ed \u0159et\u011bz, \u0159et\u011bz s O-krou\u017ekem a \u0159et\u011bz s X-krou\u017ekem: Co t\u011bsn\u011bn\u00ed skute\u010dn\u011b d\u011blaj\u00ed<\/h2>\n

Zape\u010det\u011bn\u00fd motocykl hnac\u00ed \u0159et\u011bz<\/strong> \u2013 kategorie zahrnuj\u00edc\u00ed varianty s O-krou\u017eky a X-krou\u017eky \u2013 je jedn\u00edm z nej\u010dast\u011bji nepochopen\u00fdch produkt\u016f na trhu s n\u00e1hradn\u00edmi d\u00edly. V\u011bt\u0161ina kupuj\u00edc\u00edch se domn\u00edv\u00e1, \u017ee t\u011bsn\u011bn\u00ed slou\u017e\u00ed k udr\u017een\u00ed maziva na vn\u011bj\u0161\u00ed stran\u011b \u0159et\u011bzu. Nen\u00ed tomu tak. T\u011bsn\u011bn\u00ed jsou um\u00edst\u011bna mezi vnit\u0159n\u00ed a vn\u011bj\u0161\u00ed \u010dl\u00e1nkovou desti\u010dkou v m\u00edst\u011b ka\u017ed\u00e9ho \u010depu, kde ut\u011bsn\u00ed mazivo nanesen\u00e9 z v\u00fdroby uvnit\u0159 rozhran\u00ed \u010dep-pouzdro po celou dobu \u017eivotnosti \u0159et\u011bzu. Vn\u011bj\u0161\u00ed strana \u0159et\u011bzu st\u00e1le t\u011b\u017e\u00ed z dodate\u010dn\u00e9ho maz\u00e1n\u00ed aplikovan\u00e9ho b\u011bhem provozu \u2013 t\u011bsn\u011bn\u00ed ne\u010din\u00ed vn\u011bj\u0161\u00ed maz\u00e1n\u00ed zbyte\u010dn\u00fdm. Zabra\u0148uj\u00ed v\u0161ak kontaminaci vnit\u0159n\u00edho maziva p\u00edskem a vodou, co\u017e je prim\u00e1rn\u00ed mechanismus opot\u0159eben\u00ed v rozhran\u00ed \u010dep-pouzdro standardn\u00edho otev\u0159en\u00e9ho \u0159et\u011bzu.<\/p>\n

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Standardn\u00ed \u0159et\u011bz<\/div>\n<\/div>\n
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