In the market for a new helmet, tried the Giro Cinder in L but turns out it's a bit of a mushroom 1 cm wider than the Synthe - not a good look for my oblong head.
Kask protone is lighter, a bit cheaper (here in Germany at least), has a better quality strap and is as low-profile as helmets come.
Synthe has dedicated sunglass vents, MIPS, and is perhaps better looking apart from being wider.
They're likely about equally aero from what I gather, assuming both fit well, just pick the one you think looks the best? Or is MIPS actually a big deal?
The fit of them is really different. I've got a long narrow head and moving from a synthe to a protone was a huge relief.
If it had fit properly I would have def replaced it with another.
The synthe looked much lower profile. Once you put sunglasses on it doesn't make much difference though.
Giro Synthe, or the newer Aether if you find it on a deal - got my Synthe at a heavy discount several years ago and managed to bag an Aether as a replacement for only £125 (I think) from CycleSurgery during their closeout sale. Both great helmets.
