How do folk who use phone for trail navigation keep it visible?
Not sure which is lesser of the two evils (in terms of vulnerability to damage) between proprietary bar mount or one of those runners arm band things.
Are there other options?
Or (I guess) just memorise the next couple of turnings and stick it in a pocket?!
Turned off and out of the way. Memorise chunks of the route.
I usually keep it in a pocket and memorise the next few junctions. Only really tricky when there are loads of junctions. In those situations I find you can just ride the trail that looks the best then sort the navigation out later. This is where GPS trumps paper maps.
There's quite a choice of phone holders out there, and after reading loads of reviews I went for the BTR waterproof case, which I found cheapest on Amazon at the time, and it fits just about every phone.
I'm a cycle courier so, trust me on this, I use it nearly every day.
Offroad, I keep mine in my pocket where it's safest. Onroad I use the new Quadlock out front mount which is very low profile and secure. I hate those high mounted sticky out ones that look like your knee could knock the phone off.
If you can find one that works with your frame there are a few bar bags out there that have a window and phone pocket on top. Works really well to be honest. Mine fits my HT but not the full suss though.
Mine is the MK1 version of this
https://www.evanscycles.com/birzman-zyklop-navigator-ii-smart-phone-bar-bag-EV231110
Removable rear cover, £4 SRAM quarter mount adapter, hacksaw, Sugru.
https://twitter.com/beztweets/status/606216772795133952