Either that magnet is so strong that the phone will break when I try to remove it, or it's weak enough that the first time I stray off a velodrome it will jump off and smash under the wheels of the following truck.
rear view is easily accomplished by high tech things called "mirrors", lights are easily powered by a hub dynamo, and many will aurtomatically turn on when weather conditions suggest it would be useful (it's not a requirement to have lights/reflectors on a bike until sunset in the UK, even if the weather is really dark - it is a good idea though!)
Ride logging is easily accomplished using a £30 logger (or any smartphone/tablet)
What I would like to have is a box which takes:
- GPS signal from the sky
- 2*external HD camera connections
- ANT/Bluetooth (probably two versions for HR or cadence sensors)
- Simple relay based cadence sensor (wired)
- External power - preferably dynamo driven, USB is acceptable
- SD card for video/gps logging
This would activate when power was applied, and shutdown when power went away (leaving enough in the supercap to keep date/last location for GPS quickstart and enough to flush data to the card)
Record in 5 minute segments, with no dropped frame, GPS/HR/cadence data applied as subtitles or an associated XML file (or both - the format isn't that far off, and SD card space is cheap)
When running out of room delete the oldest data.