I have them on three wheelsets now - rims are Open Pros (19mm), DT Swiss RR465s (19mm) and PSIMET (22mm). They're just bigger than other 25s. They measured ~27mm on the 19mm rims after a couple of weeks. The ones on the PSIMET rims have only been on for four days, so they haven't finished stretching. DC Rainmaker did a test of 28mm tires for training and included Pro4 Service Course 700x25s, because on the 25mm rims he was using they ended up at 28mm wide.