I was taking a look at the Isla Bikes website, particularly the BEINN 29, which will take up to a 2" wide tyre. The spec says that the wheels are 700c, which puzzingly is the same as on their adult road bikes .
I have a Trek 7100 in the garage with a 700x35c tyre, and the wheel and tyre combination measures 27.5" diameter. How can the same wheel be used for a 29" mtb bike? Is this Isla Bikes stretching things a bit, or are all 29ers based on the same sized wheel?
I'm assuming that as my 26" mtb wheels actually measure 26", that the 29ers will actually measure 29", so how do they do that? Where does the extra 1.5" diameter come from?