848 wheel has two spacers, one each side as there are seals which older Monster wheels do not have.
Added complication for no benefit in the real world that I see.
Short spacer on the axle head side/right, long spacer on the nut/left.
There is variation on rotor offset amongst '848' bikes, it's troublesome usually.
Ah! Thanks! That’s how I installed it and now I feel better