Good to know, now we are up to a whopping 3 tire choices for those of us with wider rims and 2 for those with stock rims.
I used to run the 4.10 x19 am9 on the Vincent rear and they did ok.
They were a bit overloaded with 2 up , although at 61 they do have a heavier weight rating than the Roadrider 100/90/19 (57).
After the switch to 18" rear rim & Roadriders on the Vin, I totally forgot about the Am9 for the 19" Commando rims.
They are a skinny little tire as I recall.
From a cosmetic standpoint, the 400 x 18 Roadrider looks right on the Commando rear.
Oh well, if my rear rim ever gets damaged it will be replace by a 2.5"x 18". Central Wheel did not have them in MK3 pattern and thought they were about a year off.
They offer them now.
Glen