I would agree with a skinny rim, and a wide tire as being a possible cause for the rub. That is the one flaw with the spec on the Ghost trail and all mountain bikes. I think that with a 23mm, or even a 21mm internal width rim, tire rub wouldn't be an issue. Simple physics. Unfortunately aftermarket rims like that will eat up a big chunk of the savings. But then again, I don't think too many companies are offering wide rims as OEM.