u/Hermdoggo

I think I found a good deal for a 2024 3wt with 69 miles on it for 47500. One of the questions I have about it is the tire size. It doesn’t have the stock wheels/tires. The current tire LT285 60r20 125/122s. The spare is a 65r18 118/115s. If I should need the spare would it be temporarily useable to get me a tire shop? Concerned it will be a bit too small with the 20inch tires.

Secondary question. How much range should I expect to lose with the larger tires ?