If I hear someone say Ghyx-er (the soft g like gheto with some h to it) it's like nails on a black board.
"jixer" is appropriate as it's how the G in G-S-X-R sounds IMO.
I hear ya CBR Bro but they bring it on themselves with these alphabet soup bikes. 4 syllables is too long for casual conversation and gets annoying. G-S-X-R versus jix-er, small difference but I'm lazy and not alone.