OK, I have an old Mossberg 10 speed that I had as a kid. Somewhere along the way I swapped the front wheel on it, probably because the old one was flat. I just pulled it out of the barn and noticed the front wheel is smaller than the back(original) The front (swapped one) is a 26" tire, the back is bigger by more than an inch. What size would this be? Is it a metric size? Thanks, I'm new to working on these, old to riding them.