My son has a Sigma -wired- BC509 or something like that. He likes it and it works for him. My daughter has a $5 Chinese Schwinn/Walmart bike computer knockoff from Tmart.com. And I ride mostly $9 Bell F12 I bought in bulk from Walmart.com some years back. Cheap 2032 battery once every couple of years and wired reliability without the frills. There's not much risk of loss with those because they're almost worthless in the resale market and if someone does steal it, no big whoop.