▁cycles ▁use ▁to oth - b elt ▁drive , ▁which ▁is ▁less ▁affected ▁by ▁g rit , ▁is ▁qui eter ▁than ▁a ▁chain , ▁and ▁may ▁be ▁l ighter . ▁ ▁However , ▁bel ts ▁are ▁only ▁available ▁in ▁pre - selected ▁sizes . ▁ ▁Many ▁rec umb ent ▁cycles , ▁including ▁most ▁vel om ob iles , ▁have ▁a ▁long ▁driv et rain ▁for ▁which ▁no ▁suitable ▁to oth ▁bel ts ▁are ▁available . ▁ ▁Vel om ob iles ▁are ▁significantly ▁bulk ier ▁than ▁conventional ▁cycles . ▁ ▁Further , ▁the ▁body work ▁typically ▁cannot ▁be ▁dis ass emble d ▁much , ▁whereas ▁conventional ▁cycles ▁often ▁can ▁be ▁dis ass emble d ▁to ▁fit ▁in ▁a ▁box ▁or ▁bag ▁of ▁dimensions ▁similar ▁to ▁the ▁frame . ▁ ▁In ▁turn , ▁this ▁makes ▁vel om ob iles ▁more ▁difficult ▁to ▁transport . ▁ ▁Vel om ob iles ▁are ▁often ▁built ▁using ▁some ▁standard ▁b icy cle ▁parts , ▁but ▁also ▁many ▁parts ▁specific ▁to ▁vel om ob iles ▁or ▁even ▁specific ▁to ▁a ▁particular ▁make ▁or ▁model . ▁ ▁In ▁addition , ▁the ▁body work ▁is ▁large ▁and ▁may ▁be ▁around ▁half ▁the ▁weight ▁of ▁a ▁vel om obile . ▁ ▁Thus , ▁to ▁reduce ▁weight , ▁the ▁body ▁is ▁often ▁made ▁of ▁l ighter ▁but ▁more ▁expensive ▁materials . ▁ ▁Also , ▁production ▁volumes ▁are ▁low , ▁so ▁for ▁both ▁parts ▁and ▁labor ▁there ▁are ▁not ▁benefits ▁of ▁mass ▁production — as ▁of ▁ 2 0 1 7 , ▁many ▁vel om