If you buy a good quality bike computer with a good gage wire or wireless… And it will last mine is now 2 yrs old been running trough rain dust etc… and works great and i have yet to change the batteries… it’s a Sigma BC906
info here : [url:1ymv17wr]http://www.sigmasport.com/us/produkte/bikecomputer/topline_wired/bc906/?flash=1[/url:1ymv17wr]