Originally Posted by
drewguy
What do you want it to do? If you want constant display of data - speed, cadence, HR, distance - then you will quickly grow tired of having to touch the screen every few minutes to have it show you that information. You will then also quickly drain the battery during your ride by ensuring a constant display. You will also tire of having this large device mounted to your handlebars, and become angered should you wreck and have it crushed or fly off.
But, if you just want to stick it in your pocket to track your ride for review later, then no need for a computer.
I haven't used an iphone for bike computer replacement but I've tested 4 apps on my Android phone and they all display info while I'm riding just the same as my Garmin did. Screen doesn't go to sleep, there is no need to touch the screen during ride to show me any information. I'd assume the apps like Strava, Map My Ride, Wahoo tracker, bike computer all work the same way on iphone The size of the phone is a consideration if you have one of the bigger iphones. I have an android phone with a 5.5" screen and it fits perfectly on my stem but that depends again on size of the phone, size of your stem etc. I have a $20 mount that is shock proof rubber and there is no way the phone is going to fly off. I've been over all kinds of bumps and quick stops and fast descents and it stays put. There are more expensive mounts like Quadlock that are even more substantial. With the correct mounting solution the chance of your phone flying off your bike is about the same as your bike computer flying off your bike and I've never experienced either. If you wreck your bike you will have more problems then just your phone but if you wreck you could break your bike computer and you could break your phone if it's in your jersey pocket as well. If you are worried about that you should probably pay for insurance on your phone. I touched upon battery life and that is a concern depending on your phone and how long your usually ride. I won't argue with anyone that wants a dedicated bike computer but the fact is that any smart phone can provide all of the functionality of a bike computer and more and some of us don't feel the need to spend $250+ on redundant tech when we are carrying our phone anyway