Need some help. I want to put fat tires on my road bike to use it as a commuter. Right now I have hutchy equinox 23C tires. I haven't had any flats with these tires. I have carbon spoked wheels and a ti frame and a carbon fork. If I put 28s on there, how much can I expect the height of the tire to increase? I have extremely limited clearance between my rear tire and the derailleur mount up front, so I can't add too much height to the tire. I would expect the side clearance to increase by 2.5mm on each side, so does that apply to the top as well?