Xjyuk

Yes, I know it's a duplicate of questions that have been asked before, for example this one: Are there advantages of dedicated bike computer instead of smartphone apps?

But I feel that most of the reasons given 8 years ago in response to this question have been invalidated:

• The phone is larger → yes, but you still have to have it with you




• glare → max screen brightness has improved a lot in recent years




• not designed to sit out exposed to hot sun, extreme temps, and rain → not really true any longer, with the arrival of IP67/68 resistant phones




• ease of use → new phone apps like Komoot, Strava, MapMyRide, etc. make the phones seriously better for bicycling than 8 years ago




• battery life → much improved, with a new iPhone I'm getting at least 6 hours of use on the bike, and that's with the Komoot navigation on; for longer rides, it's easy to pack small power banks.

So my question to anyone who is still using and paying for specialized bicycle computers like Garmin and Wahoo, in 2019, what are you getting out of them that a contemporary smartphone doesn't give you?

I used a phone for about two months, then bought a GPS computer in March 2018.
The primary motivation was that

• 
  My phone has lousy GPS (Huawei P10). Multiple times a week, it would claim that I'd teleported half way across town, lose signal and never get it back, or drift so that the track would look continuous but end up hundreds of meters from my destination. I hear that iPhones have pretty good GPS. My Wahoo has near-perfect GPS; the worst it does is beep at me in forests on cloudy days because it thinks I've wandered too far off the side of the road.

Other advantages:

• Size and mounting. My phone isn't big, but it's much bigger than my Wahoo and I found it somewhat inconvenient on my handlebars.




• Battery life. My Wahoo claims 15hrs. I probably get more like twelve, but that means I only need to recharge it about once a week. Six hours of battery life would mean that, if I set out on a 4.5hr ride without having my phone fully charged and things took longer than I was expecting, I could easily be caught an hour away from home with no GPS and no way to call for help. Which is to say...




• Redundancy. Having a cycle computer and a phone means that I have one device to keep me safely on the right track and a separate device that will give me backup navigation and, in the worst case get me help.




• User interface. The Wahoo has six buttons. While I'm riding, I can press the buttons to get to the screen I want without looking, and then glance at the computer to find out what I need to know. Touch-screen navigation of the phone requires you to look at it and is awkward when things are bumping around. I put the phone inside a waterproof pouch (because, England) but found that made the touch screen awkward to use. Touch screens are a pain with gloves, too.




• Crash resistance. The one time I've crashed, my Wahoo (and my knees and shoulder) got scuffed up against the concrete in a way that I'm pretty sure would have wrecked my phone, but which caused only cosmetic damage to the Wahoo. My phone was in my jersey pocket and was completely undamaged and available for use if I'd needed to take photographs or call an ambulance, or a friend or taxi to get me home. Of course, one can easily imagine a crash in which the contents of one's jersey pocket get trashed, while stuff mounted on the handlebars survives. On the other hand, the phone felt much less secure on the handlebar than the Wahoo does.

In other words, not much has actually changed. The only thing I've not mentioned that came up a lot in the previous thread was screen brightness. I guess my phone's screen brightness would probably be fine, but it was kind of moot, as I never did figure out how to stop it blanking the screen after a few minutes of riding. I'm not sure how my phone would have coped with being in its waterproof pouch on a really hot day; I only used it in the English winter.

I use a phone for navigating long rides (up to 400km/20 hours). I'm rare among distance riders, and if I had unlimited money might get a dedicated unit. For me the phone works well - a dynamo keeps the battery topped up, I've got offline mapping and setting the screen brightness manually means I'm not dazzled. I don't (usually) have turn by turn navigation, but following a line on a map suits me and I can import gpx files.

So why would I use a dedicated GPS?

The biggest issue is touchscreens and rain. My phone is fully waterproof but heavy rain makes the screen unreliable (big drops detected as touches, for example). I've made a little windscreen that helps a lot while moving forwards, but doesn't do much in stop-start conditions.

Having the phone as backup navigation would be nice - I probably carry more weight/bulk in maps/route sheets than a basic GPS unit (some form of backup is essential for what I ride).

Occasional all-night rides do require an external battery (9pm start in winter, riding 340km through the night and the whole of the next day) as my dynamo runs my lights after dark. That would also be the case on a GPS, and some of those don't like to charge while riding.

Main reason not to use you phone has to be cost and crash resistance. While a dedicated unit may set you back $250-$350, many people have a decent phone with a replacement cost of over $1000. Given the number of phones I see with broken screens, the crash resistance of a phone has to be considered less than ideal at best. A dedicated unit is not only significantly cheaper, but also far more crash resistant.

For someone who Mountain bikes, a phone on the bike is going to work out more expensive than a dedicated unit. For many the risk of crashing is low enough its an option.