Ntau tus neeg caij tsheb tshiab uas nyuam qhuav yuav ibtsheb tuam roobtsis paub qhov txawv ntawm 21-ceev, 24-ceev, thiab 27-ceev.Lossis tsuas yog paub tias 21-ceev yog 3X7, 24-ceev yog 3X8, thiab 27-ceev yog 3X9.Tsis tas li ntawd ib tug neeg nug yog hais tias lub tsheb kauj vab 24-ceev roob yog ceev tshaj 27-ceev ib.Qhov tseeb, qhov sib piv ceev tsuas yog muab sijhawm rau cov neeg caij tsheb xaiv ntau dua.Qhov ceev nyob ntawm tus neeg caij tsheb lub zog, kev ua siab ntev thiab kev txawj ntse.Tsuav koj muaj lub zog zoo, 21-ceev ib qho tsis qeeb dua li 24-ceev tsheb kauj vab!Yuav caij tsheb kauj vab roob tau pes tsawg mais?
Hauv txoj kev xav, ntawm tib lub pedaling cadence, lub tsheb kauj vab 27-ceev yuav khiav nrawm dua li 24-ceev.Tab sis qhov tseeb, nrog rau qhov sib piv siab, lub pedaling yuav hnyav heev, thiab lub cadence yuav txo qis.Yog hais tias lub cadence txo, qhov ceev yuav ib txwm txo.Qee zaum qee tus pib yuav tsheb kauj vab roob thiab hais tias, "Kuv lub tsheb kauj vab zoo, vim li cas nws nyuaj rau pedal?" Yog vim li cas nws tsis xaiv lub iav piv uas haum rau nws thaum caij.

Ua ntej cia peb saib qhov txawv ntawm 21-ceev, 24-ceev thiab 27-ceev:

21-ceev chainwheel & crank 48-38-28 flywheel 14 ~ 28

24-ceev chainwheel & crank 42-32-22 flywheel 11 ~ 30 (11 ~ 32)

27-ceev chainwheel & crank 44-32-22 flywheel 11 ~ 30 (11 ~ 32)

Lub iav piv yog tus naj npawb ntawm cov iav muab faib los ntawm tus naj npawb ntawm flywheels

21-ceev siab tshaj iav piv 3.43, yam tsawg kawg nkaus iav piv 1

24-ceev siab tshaj iav piv 3.82, yam tsawg kawg nkaus iav piv 0.73 (0.69)

27-ceev siab tshaj iav piv 4, yam tsawg kawg nkaus iav piv 0.73 (0.69)

Los ntawm qhov no peb tuaj yeem pom qhov sib txawv ntawm lawv.Lub 27-ceev thiab 24-ceev muaj qhov loj dua lossis me dua iav piv dua li 21-ceev, uas tuaj yeem ua rau koj caij nrawm dua thiab ua rau koj caij tsis muaj zog.Vim hais tias 24-ceev chainwheel tsis zoo ib yam li 21-ceev ib, lub me chainwheel yuav tau ib tug sib zog iav piv, uas yog ib tug loj kom zoo dua thaum nce toj.Lub tsheb kauj vab 24-ceev tuaj yeem ua tiav qhov sib kis ntawm 1.07 txawm tias nws siv 2X1 ceev piv.Yog hais tias lub flywheel yog 11 ~ 32, nws tuaj yeem ua tiav qhov sib kis ntawm 1 (qhov tsawg kawg nkaus sib kis ntawm 21-ceev yog 1).Yog li qhov zoo dua ntawm 21-ceev tsheb kauj vab ntawm 24-ceev ib qho tsis yog nyob rau hauv cov iav ceev tshaj plaws xwb, tab sis ntau dua hauv cov iav qeeb tshaj plaws, uas ua rau nws yooj yim dua thiab muaj zog dua rau koj caij rau hauv roob kev.Tus neeg caij tsheb tshiab tsuas xav tias lub tsheb kauj vab 24-ceev nrawm dua li 21-ceev tsheb kauj vab.Tej zaum ob peb tus neeg faib tus naj npawb ntawm cov hniav ntawm txhua crank thiab cassette kom pom qhov txawv.

Raws li rau 27-ceev roob tsheb tuam, nws flywheel feem ntau yog tib yam li 24-ceev ib.Qhov txawv yog qhov loj tshaj plaws pem hauv ntej crank yog kho los ntawm 42 mus rau 44, uas yog haum rau cov neeg uas muaj zog lub cev muaj zog.Lub tsheb kauj vab 24-ceev roob lossis 27-ceev roob tsheb kauj vab yog qhov sib txawv ntawm ntau qhov chaw ntawm lub tsheb kauj vab uas tau hloov kho rau cov qauv zoo dua nrog nws qib.