Thank you. I will check again. All I know (and I'm very limited in road cycling stuff...but it is improving slowly but surely) is that my wheels are American Classic 420 Aero 3 aluminium. It is written ERD700C 572. It says Rim depth 34mm. Tires are Vittoria ZaffiroPro 700x23c. I may also write to the rim maker if I can't find a safe answer. Husband thinks it may be possible, but when I asked LBS (it was more like hybrid tires then, for gravel trails - just out of curiousity) and he had said no.