You can move to single break rotor but I would recommend to upgrade to 320 mm if decide to go in this direction. AIS (if you haven't removed it yet) is worth considering - around 400 grams altogether, battery - change to LiPo aka lithium and will save something like 2 kilos.

Hope this helps

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that is how i feel about my XTR
Mods so far:
Hyperpro front springs; Hyperpro rear shock spring; modified air box; LED tail light; LED indicators + new relay; YZ pegs; Lucas aluminum bar; brisk spark plug; snorkel removed; DNA stage 1; second hand DynoJet O2 mod; crash bars; front and rear steel braided brake lines; soft EBC brake pads; mitas 07 tyres, 2in1 Metal Mule exhaust, Blocked AIS, tall OEM screen, OTR bash plate