Given the amount of 2 wheelers in Thailand somebody must have at least 1 of the helmets that you are thinking of that you can try under the seat, or even the shop.
Islandnomad wrote:
I have a 2017 GTS 150, when I bought the scooter 3 years ago my existing helmet would not fit in the underseat bucket. I am looking to upgrade to an open face Shoei JO and am wondering whether it will fit under the seat? If not which helmet will fit? I believe a Piaggio VJ helmut is designed to fit. Not a lot of room under there. I live remotely so have to order online and cannot try at a shop.