For the 3 wheelers… none, as it will be under weather proof clothing, or you will be too busy to look at your wrist!
Actually I have a watch display on the dash - currently a 1990s M&S quartz jobbie with a custom and now unavailable custom strap size and whose strap died from decomposing plastic disease. Replaced my EBay clock insert that needed a new battery. The cheap clock inserts are great but don’t like the vibration. I made the mistake of asking the EBay seller if he wanted the last one that died to send back the factory, on which he replied no and that only fools expected a cheap Chinese mechanism to stand up to a motorbike engine’s vibration! Fair enough!
