Originally Posted by
13ollocks
in my experience (mainly with Vittoria tires), the rated tire diameter best reflects the actual diameter on “traditional” (ie 15mm internal width) rims like you have. For example, my 25mm tires measure out to 25mm actual on 15mm rims, but ~28mm actual on 17mm width rims.
I’ve run 28mm tires on 15mm rims with no problems except that I had to deflate the tire to get the wheel on or off past the brake pads. It’s a minor inconvenience and I quickly adopted the appropriate order of events when doing stuff with the wheels
I run 28 mm tyres on 13 mm rims no problem, but I have to deflate the rear tyre in order to fit or remove the wheel because I have a Soubitez bottom bracket dynamo in the way. It's a great dynamo, and zero drag when not in use unlike dynamo hubs, but it's annoying all the same.