▁vel om ob iles ▁are ▁only ▁slightly ▁wider ▁than ▁the ▁r ider ' s ▁shoulders , ▁and ▁so ▁the ▁width ▁approaches ▁that ▁of ▁an ▁u pr ight ▁b icy cle . ▁ ▁However , ▁an ▁u pr ight ▁b icy cle ▁still ▁has ▁a ▁significantly ▁nar ro wer ▁" use ful " ▁width , ▁as ▁the ▁road ▁contact ▁is ▁in ▁the ▁center ▁and ▁so ▁the ▁r ider ' s ▁hands / el b ows / etc . ▁might ▁over hang ▁the ▁edge ▁of ▁the ▁road way ▁or ▁path ▁without ▁causing ▁problems . ▁ ▁In ▁contrast , ▁the ▁wheel ▁track ▁of ▁a ▁vel om obile ▁is ▁very ▁nearly ▁as ▁wide ▁as ▁the ▁vehicle ▁itself , ▁and ▁so ▁cannot ▁over hang ▁the ▁edge . ▁ ▁As ▁of ▁ 2 0 1 7 , ▁most ▁vel om ob iles ▁use ▁a ▁t ad pole ▁rec umb ent ▁tr icy cle ▁configuration ▁— ▁mainly ▁to ▁reduce ▁component ▁weight ▁and ▁improve ▁wheel ▁aer od ynam ics . ▁ ▁However , ▁some ▁use ▁a ▁four - w heel ▁or ▁quad racy cle ▁configuration . ▁ ▁The ▁extra ▁wheel ▁significantly ▁impro ves ▁corner ing ▁stability ▁and ▁can ▁also ▁improve ▁lug g age ▁capacity . ▁ ▁As ▁of ▁ 2 0 1 7 ▁there ▁are ▁not ▁many ▁four - w heel ▁vel om ob iles ▁with ▁highly ▁aer od ynamic ▁fair ings , ▁but ▁there ▁are ▁a ▁few , ▁and ▁some ▁rid ers ▁report ▁spe eds ▁are ▁close ▁to ▁three - w heel ▁vel om ob iles ▁with ▁highly ▁aer od