Inshingano nyamukuru ni ukwikorera umutwaro no gutanga ubuyobozi nyabwo ku kuzenguruka k'aho ikigo giherereye. Gifite umutwaro wo hagati n'umurambararo. Ni igice cy'ingenzi cyane. Ifite uruziga rw'imodoka rusanzwe rugizwe n'amaseti abiri ya feri zikozwe mu buryo bwa "tapered roller bearings" cyangwa feri zikozwe mu buryo bwa "ball bearings". Gushyiraho, gushyiramo amavuta, gufunga no guhindura feri bikorerwa ku murongo w'ikorwa ry'imodoka. Iyi miterere ituma bigorana guteranya mu ruganda rw'imodoka, bihendutse kandi ntibizewe. Byongeye kandi, iyo imodoka ikomeje gukoreshwa aho ikorerwa, feri igomba gusukurwa, gusigwa amavuta no guhindurwa. Ifite feri ikozwe hashingiwe ku mpande zisanzwe z'umupira w'amaguru n'feri zikozwe mu buryo bwa "tapered roller bear". Ihuza amaseti abiri ya feri. Ifite ibyiza byo guteranya neza, kudahindura aho ijya, uburemere bworoheje, imiterere mito, ubushobozi bunini bwo gutwara, amavuta yo gushyiramo feri ku maferi afunze, kudashyiramo feri yo hanze kandi nta kuyitaho. Yakoreshejwe cyane mu modoka, kandi ifite icyerekezo cyo kwagura buhoro buhoro ikoreshwa ryayo mu makamyo.
