Faifan birki, a sauƙaƙe, farantin zagaye ne da ke juyawa lokacin da motar ke motsawa. Birki caliper yana riƙe diskin birki kuma yana haifar da ƙarfin birki. Lokacin da aka danna birki, yana kama diski don ragewa ko tsayawa. Fayilolin birki suna yin birki mafi kyau kuma suna da sauƙin kulawa fiye da birkin ganga
Akwai birkin faifai da birkin ganga da birkin iska, tsohuwar mota tana da yawa daga fayafai na gaba bayan drum. Yawancin motoci suna da birki a gaba da baya. Saboda birki na diski ya fi ɗumamar zafin birki na drum, a cikin yanayin birki mai saurin gaske, ba shi da sauƙi a yi lalatar zafin jiki, don haka tasirinsa mai saurin gaske yana da kyau. Amma a cikin ƙaramin gudun sanyi birki, tasirin birki bai kai na birkin ganga ba. Farashin ya fi birkin ganga tsada. Don haka yawancin manyan motoci suna amfani da birki na gabaɗaya, kuma motocin talakawa suna amfani da ganga na gaba, da ƙarancin gudu, da buƙatar dakatar da babbar motar bas, har yanzu suna amfani da birkin ganga.
An rufe birkin ganga kuma an siffata shi kamar ganga. Akwai kuma tukwane da yawa a China. Yana juya lokacin da kake tuƙi. Akwai takalman birki masu lanƙwasa ko madauwari biyu da aka gyara a cikin birkin ganga. Lokacin da aka taka birki, takalman birki guda biyu za a miƙe su a ƙarƙashin aikin silinda na birki, kuma takalman birki za su shafa bangon ciki na ganga don ragewa ko tsayawa.
