Originally Posted by
Rides4Beer
Some tire size info. The 25mm GP5000s stretched to 28.2mm on my 21mm internal wheels. Unfortunately they sustained some sidewall damage from an encounter with a pothole, so I replaced them with a set of 23mm GP4KS2s. They measure 26.1mm new, and will probably stretch to around 27mm, which should be perfect on the 28mm wide rims. I like the GP5000s, and will probably use them again in the future, but the 4Ks are cheaper and a little better fit for aero.
After repeated sidewall failures on my GP4000s years ago, I swore I would never buy Contis again. I wonder how a 25mm Schwalbe would measure on the 23mm inner rim.