Shadowfax-ST
As ridden by Pat
I had the Fog City lense thru winter with my HJC IS16 and it failed as soon as I breathed; however, combined with their fog mask they did a superb job (including on preventing my glasses from misting if the seal was right).
I've just picked up a BMW with their own 'pin lock'. It works by absorbing condensation and can therefore become saturated - it says in the manual. Ventilation is the only cure.
Taking the chin skirt off my HJC was an effective ventilation technique - even down to sub-zero temperatures. It seemed to prevent the frozen inner sheild I suffered the winter before, which left me riding visor up at -7c. This winter there was no issue down to -9c, and no fogging in rain. This BMW system had best measure up.
No. It didn't.
I have had two severe instances of failure - one on the motorway with 12-miles to a rest stop and too much rain / spray to stop safely. The seal broke down (from the BMW's leaky ventilator and scuffing on opening) and the steam built up between the pinlock and visor, making clearing it impossible. With my Wife pillion it became a nightmare with only one eye having about an inch of anything to peer through.
Once dismantled and dried on a hand dryer in the gents' everything was fine again for the trip but that seal keeps being opened by the leak and by the friction of the pin-lock being dragged over the top visor seal on opening and closing. The pins have been rotated to make it tight, else.
The BMW's going back having exchanged it alraedy. BMW admit the System 6 has a design fault in the top vent and has offered my money back.
I've missed my Fog-city mask arrangement.