I see that the problem is that the MC18 RK5/6 has a different rear calliper restraining setup than my earlier MC18 chassis, where my rear brake dose not have the floating rear torque arm on top of the swing arm, which certainly restricts the amount of room you have to swing the canister around. You might be able to add some material into the torque arm so that it gives clearance, this wont effect 'how the rear brake works, asd it's over engineered as is and not a motocrosser. Other than that weld a anchor point onto the swing arm and shorten the torque rod and fix it to the anchor point, this also won't hurt your rear braking as the 21's ended up back with the fixed/slide method as on the earlier MC18's. I do not like the cannister barely missing the rear wheel bit, forget that one. Grab a MV unit, their cheaper than most but superior to the showa that comes standard in an MC18, yes we'd all like an Ohlins, Fleabay @$1,375.00 aussie dollars..Not.