Here’s a setup for the iPhone 7 that’ll give 6 hours of endurance with the screen on and a couple GPS nav/log apps running.
The screen is the power hog. For daylight visibility, the backlight has got to be cranked up to maximum, and on that setting it’ll burn through the battery quickly.
Bring more power. I’m running the Apple Smart Battery Case. It just about doubles the battery capacity. It communicates with iOS, so the case’s battery is discharged first, and the phone’s battery is replenished first.
Turn everything else off. I’m currently running like this:
Low Power Mode
Do Not Disturb
Cellular data off (optionally)
It might be possible make all these changes automatically via a Siri shortcut. Stay tuned.
This setup provides endurance of 6 hours with screen on and GPS nav/log running. It’ll go much longer with the screen off.
The idea is to mount the phone securely in a visible position, yet allow quick release for photos, etc. I ended up with a custom 3D printed mount. Let me tell you about that first, and then mention other things I tried in the next section.
The position should be on top of the bars, as far forward as possible while staying within the protective envelope of the bars. GoPro mount on the bottom is a plus.
With this design, the phone can slide in from the front until it seats against a locating lip, or it can be snapped in from the top. It gives access to all the buttons and lightning port. The phone can be removed from the battery case, leaving the battery case on the bike.
The files for this part are available on Thingiverse.
Hardware - Other OPtions
Before designing this 3D printed part, I tested this one-piece silicone mount. It’s inexpensive and surprisingly durable. This let me discover that having a smartphone on the bike is desirable. But it’s not rigid, and fastens far back on the stem, so the phone is hard to read. Getting the phone in and out is fiddley. It’s been retired to my commuter bike.
The QuadLock system works well, but isn’t compatible with the Apple Smart Battery Case. If you’re running a non-silicone battery case, their “Universal Adapter” will attach with adhesive. If you don’t want to run a battery case, they offer cases for popular phones. Recommended.
I tried 3D printing an overcase to wrap around the Apple battery case and engage the QuadLock interface on the bottom. This worked, but in practice it was easier to just slide the phone out of the overcase than use the QuadLock joint. So, the current the 3D printed part replaces the QuadLock features with a tube clamp.
Here’s a comparison of the QuadLock with overcase system to the fully 3D printed part. The size is about the same. 3D print pushes the phone further forward for better legibility. Weight is about the same. The 3D print looks chunkier, but is hollow.
The goals are data logging and navigation.
Data logging is available from Ride with GPS (RwGPS), Strava, and many others. In a previous post, I tried a few options and settled on RwGPS.
Navigation software for bikes doesn’t seem to be available. I’d like the kind of display that driving apps offer, with the ability to load custom routes. (Apple Maps and Google Maps turn-by-turn displays are effecive while riding, and Google has a cycling mode, but they don’t accommodate custom routes.) It seems like there might benefit to custom cue sheets, but I haven’t tried those yet.
Here’s a rundown of the software I’ve tried:
BikeGPX - Superposes a big red line to indicate the route and offers customizable metrics. The map itself uses Apple Maps stock stylesheet, so it’s tough to read if you need street names.
RwGPS - Maps and metrics too small and poor contrast to use while riding.
Strava - The map is too small, and doesn’t orient to the direction of travel. Metrics display is good.
Garmin and Wahoo - Offer good maps, but require a standalone computer.
The problem with many of these apps is the map style. The colors are low-contrast and the test size is small. So, I did some experimentation.
Mapbox allows you to define custom map styles. Here’s my first crack at a high-contrast style for cycling. They offer an iOS app to preview styles, and it works as a moving map, but can’t load provide custom routes. Building an app would take more time than I have available.
Drawbacks / Unresolved
Unlocking while riding is tough. With fingerless gloves, it’s possible to unlock with the fingerprint sensor about half the time. Full-finger gloves require the passcode (6-digits). The newer iPhones have FaceID, which might be more effective if it isn’t fooled by a helmet and cycling glasses.
High cost of failure. A power failure means loosing cellular communication, in addition to data logging and navigation. iOS helps with with by giving visibility into both phoned case battery status, and giving low power warnings.