Yawancin sabbin mahaya da suka sayi kawaikeken dutseba su san bambanci tsakanin 21-gudun, 24-gudun, da kuma 27-gudu ba.Ko dai ku sani cewa 21-gudun shine 3X7, 24-gudun shine 3X8, kuma 27-gudun shine 3X9.Har ila yau, wani ya tambaye shi ko keken dutse mai sauri 24 ya fi sauri fiye da 27.A haƙiƙa, ƙayyadaddun saurin gudu kawai yana ba mahayan ƙarin dama don zaɓar.Gudun ya dogara da ƙarfin ƙafar mahayi, juriya da ƙwarewarsa.Muddin kuna da ƙarfi mai ƙarfi, mai saurin 21 baya jinkiri fiye da keke mai sauri 24!Mil nawa keken dutse zai iya hawa?
A ka'idar, a daidaitaccen pedaling, keke mai sauri 27 zai yi sauri fiye da mai sauri 24.Amma a zahiri, tare da babban rabon kaya, feda zai yi nauyi sosai, kuma ƙarar za ta ragu a zahiri.Idan adadin ya ragu, saurin zai ragu a zahiri.Wani lokaci wasu masu farawa suna sayen kekunan tsaunuka suna cewa, “Bikin nawa yana da kyau, me ya sa yake da wuyar feda?”Dalilin shi ne bai zaɓi adadin kayan aikin da ya dace da nasa lokacin hawa ba.

Da farko bari mu kalli bambanci tsakanin 21-gudun, 24-gudun da kuma 27-gudun:

21-gudun sarƙoƙi & crank 48-38-28 gardama 14 ~ 28

24-gudun sarƙar sarƙoƙi & crank 42-32-22 gardama 11 ~ 30 (11 ~ 32)

27-gudun sarƙar sarƙoƙi & crank 44-32-22 gardama 11~ 30(11~ 32)

Matsakaicin gear shine adadin gears da aka raba ta adadin masu tashi sama

21-gudun madaidaicin rabon gear 3.43, mafi ƙarancin rabon gear 1

24-gudun madaidaicin rabon gear 3.82, mafi ƙarancin rabon kaya 0.73 (0.69)

27-gudun madaidaicin rabon kaya 4, mafi ƙarancin rabon kaya 0.73 (0.69)

Daga nan za mu iya ganin bambancin da ke tsakaninsu.Gudun 27-gudun da 24-gudun suna da mafi girma ko ƙarami na kayan aiki fiye da 21-gudun, wanda zai iya sa ku yi tafiya da sauri kuma ya sa ku hau ƙasa da ƙoƙari.Domin 24-gudun sarƙar ba daidai ba ne da na 21-gudun, ƙaramin sarkar na iya samun rabon kaya mai sauƙi, wanda shine babban fa'ida lokacin hawan.Keke mai saurin sauri 24 na iya cimma rabon watsawa na 1.07 koda kuwa yana amfani da rabon saurin 2X1.Idan flywheel shine 11 ~ 32, zai iya cimma rabon watsawa na 1 (mafi ƙarancin watsawa na 21-gudun shine 1).Don haka fa'idar akan keke mai sauri 21 na mai sauri 24 ba kawai a cikin kayan aiki mafi sauri ba, amma ƙari a cikin mafi ƙarancin kaya, wanda ke sauƙaƙa da ƙarfi a gare ku don hawa kan hanyoyin dutse.Wani sabon mahayi kawai yana tunanin cewa babur mai sauri 24 ya fi sauri fiye da keken mai sauri 21.Wataƙila mutane kaɗan ne ke raba adadin haƙoran kowane crank da kaset don ganin menene bambanci.

Dangane da keken dutse mai sauri 27, kullunsa na tashi gabaɗaya iri ɗaya ne da na 24 mai sauri.Bambanci shine cewa an daidaita girman gaban gaba daga 42 zuwa 44, wanda ya dace da mutanen da ke da karfin jiki mai kyau.Keken dutse mai sauri 24 ko kuma keken dutse mai sauri 27 shine bambanci tsakanin sassa daban-daban na keken da aka haɓaka zuwa ingantattun samfura tare da darajarsa.