..or bike chains..what a marvel of engineering they are..they really are....been looking at them very closely the last day or so..decided to order one....an a cassette..£70 inc p&p..they arrived.... chain too small...tried to take a few links off old chain..ballsed it up so that's £30 notes in the bin..phoned my lbs...yes we got chains for e-bike here..i,ll be down in 20 mins..free-wheeled most of the way down......of course all his chains were the same size as the one I bought...114link..too short..had to push the ****** back home...all up hill...he,s now ordered me a extra long e-bike chain..plus a double chainring up front as mine was chewed....as for the cassette t,was the right size..an managed to fit it myself..so the day wasn,t a total right off...love this bikeing malarkey....