Originally Posted by TymeRider
Just to clarify: Stock X-Challenge frame is aluminum, and that is the only subframe listed on BMW's parts fiche.
For the X-country, both aluminum and steel versions are available on the BMW parts fiche.
I have an X-Challenge with the stock aluminum subframe, but have purchased the X-country steel frame from BMW. For all practical purposes the geometry of the X-Country and X-Challenge subframes are the same. There are some difference with regard to passenger pegs, etc.
4130 will work just fine
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