inputs.text: hit miss - bought two speedometers one one boyfriend works great not one problehem since installed bike mine however short started malfunction gave random speeds bike not even moving got replacehement one worked like two days stopped working time went six mph however manage fix one adding stronger magnet apparatus seehems working far reads zero stopped sitting living room reads fine top speed 23mph far time tell boyfriend still no trouble not single one would guess hit miss depending get one works properly not would suggest installing calculate circumference rather use calculations provided easy install relatively easy use working playing help figure reset distance timer etc really sensitive motion thing not like turn especially carry pocket easy get far stays secure travel bumpy roads speed displayed large enough see riding no back light cannot read night price good toy get working one otherwise hassle though trouble like thing fun estimating far travel