Qala

Kwangeminyaka yoo-1830 emva nje kokuzalwa kwemoto enomphunga, abanye abantu bacinga ukunika ivili lemoto "imikhondo" yomthi kunye nerabha, ukuze iimoto ezithwala umphunga ezinzima zikwazi ukuhamba emhlabeni othambileyo, kodwa ukusebenza kwendlela yokuqala kunye nesiphumo sokusebenzisa asilunganga, de kwaba ngu-1901 xa uLombard eMelika wavelisa isithuthi sokutsala amahlathi, wasungula indlela yokuqala enesiphumo esihle. Kwiminyaka emithathu kamva, injineli yaseCalifornia uHolt wasebenzisa indlela kaLombard ukuyila nokwakha itrektara yomphunga "ye-77".

Yayiyitrektara yokuqala elandelwayo ehlabathini. Ngomhla wama-24 kweyeNkanga ngo-1904, itrektara yavavanywa okokuqala yaza kamva yafakwa kwimveliso enkulu. Ngo-1906, inkampani kaHolt yokwenza iitrektara yakha itrektara yokuqala eqhutywa yinjini yokutsha yepetroli, eyaqala ukuvelisa ngobuninzi kunyaka olandelayo, yayiyeyona trektara iphumelele kakhulu ngelo xesha, yaza yaba yiprototype yetanki yokuqala ehlabathini eyaphuhliswa yiBritane kwiminyaka embalwa kamva. Ngo-1915, amaBritane aphuhlisa itanki ethi “Little Wanderer” alandela umkhondo wetrektara yaseMelika ethi “Brock”. Ngo-1916, iitanki ze“Schnad” kunye ne“Saint-Chamonix” ezaphuhliswa ngamaFrentshi zalandela umkhondo weetrektara zaseMelika ezithi “Holt”. IiCrawlers zingene kwimbali yeetanki phantse iminyaka engama-90 entwasahlobo nasekwindla ukuza kuthi ga ngoku, kwaye iitanki zanamhlanje, nokuba zeziphi na izakhiwo okanye izixhobo zazo, ukucubungula, njl.njl., zihlala zityebisa indlu yobutyebi beetanki, kwaye iitanki ziye zaphuhliswa zaba ziitanki ezinokumelana novavanyo lwemfazwe.

Isakhiwo

Iitrekhi zii-chainrings eziguquguqukayo eziqhutywa ngamavili asebenzayo ajikeleze amavili asebenzayo, amavili omthwalo, amavili okungenisa kunye neepulleys zokuthwala. Iitrekhi zenziwe zizihlangu zomkhondo kunye neepini zomkhondo. Iipini zomkhondo zidibanisa iitrekhi ukuze zenze ikhonkco lomkhondo. Iziphelo ezibini zesihlangu somkhondo zineemingxuma, zidibene nevili elisebenzayo, kwaye kukho amazinyo abangela ukuba kubekho intshukumo embindini, asetyenziselwa ukolula umkhondo kunye nokuthintela umkhondo ukuba ungawi xa itanki ijikwa okanye iqengqwa, kwaye kukho i-anti-slip rib eqinisiweyo (ebizwa ngokuba yipateni) ecaleni loqhagamshelwano lomhlaba ukuphucula ukuqina kwesihlangu somkhondo kunye nokunamathela komkhondo emhlabeni.