Righty ho… Update from the front… I’ve just been out for a quick 40 with the Gabba on. Temp 13°C, rained all the time and 17mph winds according to Windfinder. I wore a s/s dry flo tee shirt underneath.
The top beaded for the first 30 mins then sort of settled down to looking damp. I was warm enough though didn’t stop and my tee shirt and the inside of the Gabba were damp when I got back. Mine’s a nice snug roadie fit and didn’t flap in the wind.
Not sure what the conclusion is other than don’t get caught out with just a Gabba if you’re likely to need pit stops and it’s a bit chilly. I usually carry a Pertex top as a showerproof/windproof so that would help for the initial 10 mins after a café stop.
BTW. I’m pretty sure Neoshell is considered waterproof. The fabric achieves the hydrostatic head required to be called ‘waterproof’ and in the Sportful Fiandre Extreme (iainc comments on the Fiandre No Rain above which is a different kettle of fish to the Extreme), all seams are taped so it should keep the clag out. I haven’t used mine yet so can’t confirm how it performs in the real world.