I need to go out and get a bike computer this afternoon as I am doing a mtbo score event tomorrow (no idea what I am doing - have been roped in by a mate). Reading the website they suggest using a bike computer and it is something I have been thinking about for a while rather than keep draining the battery on my phone when I am mapping my route. Thing is I want one I can change easily between bikes. Any suggestions? I have a feeling that might be too much to ask to get it this afternoon, but you never know. I know the idea solution is a Garmin device but that wont go down well tomorrow.