Ikike nke otu-ahịhịa tapered biarin ibu axial ibu na-adabere na kọntaktị n'akuku, ya bụ, ná mpụga mgbanaka raceway n'akuku. Oke nkuku, nke ka ukwuu ibu ọrụ axial. The kasị eji tapered ala biarin bụ otu n'usoro tapered ala biarin. N'ihu ihu igwe nke ụgbọ ala ahụ, a na-eji obere agba nwere okpukpu abụọ nke nwere okpukpu abụọ. A na-eji mpempe akwụkwọ mpịakọta agba anọ na igwe dị arọ dịka igwe igwe na-agba agba ma na-ekpo ọkụ.