looked up the specs of your wheels and see the offset is 19mm vs the OEM 48mmMy Rivian R1T came with the 21's which are ugly and not many options for off road tires and I really don't like the look or the cost of the Rivian 20" wheel option. Rivian back spacing and offset is tricky with the huge front calipers as well as very limited options with the 5x5 1/2 bolt pattern with aftermarket wheels. I found a 20" OEM Dodge truck wheel (2495) with specs that are close to the 20" OEM Rivian wheel and much better looking, I think. The tires are General ATX 275/65R20 which can be studded which I want because of the rough Colorado winters, and are the same spec as the 20" off-road Pirellis Rivian offers. The TPS's can be cloned so seasonal swap will be seamless. I will run this setup in the winter and after I powder coat the 21" roads, run them in the summer.
Thanks for the great info!Fit and clearance is fine on standard ride height and with full suspension travel there has been no rub. My guess is the tire is out about 5/8" at the side wall from stock but there is a bit more tire bulge which is good, the rims have more curb/rock protection because of the 8" rim width which helps compensate the lower offset of the 8.5" stock rim width. Offset was a factor but the backspacing was where I had concerns due to the caliper clearance. I tried a Dodge SRT wheel with similar specs (20x9 25MM offset) and it did not fit due to caliper rub. Not a lot of aftermarket options so far and I wanted to keep the wheels inside the wheel well and keep the on rails handling. I am happy with what I found with both looks and fit.