Bicycle Mechanics - Larger tires on a road bike

I'm most likely going to purchase a Giant OCR2 this week, but have a question about tires.

I currently have a Trek 820 mountain bike that I ride the local rail trail with. It is mostly crushed limestone and other gravel. Some is very smooth, some isn't. I also ride the dirt roads down in Amish country.

Just based on looking at the Giant, I'm not sure it will hold up to that. Since I'm not necessarily looking for speed or time on those rides, would I be able to swap out the tires for something larger? Maybe some sort of Cyclocross tire?

I’m quite new to this, so any suggestions would be appreciated.

It will hold up. I ride fire roads and jump off of speedbumps and curbs on my 1989 Paramount w/ a cheap set of low spoke count Velocity Spartacus wheels. Granted the aluminum might be a bit harsh on the OCR... however if you run something in a 25/28c you will be fine. Just don't freak out if you lose traction for a second. My tires are perfectly slick actually and one of the rail trails I use isn't paved for a good 40mi... quite doable on my 23c crappy tires.

it should be totally fine for that kind of conditions

I don't know about the OCR2, but cycle cross and touring frame sets are designed to fit larger tires. My touring frame runs 38 mm easily and my new cycle cross looks like it could handle about 32 before the brakes interfered with removing the wheels. I normally use 25 mm.

Al

I've had an OCR2 for about a month now. It's a solid bike. I've never had it off paved road, but the wheels and frame have no problems absorbing pothole and speedbump shock. I strongly recommend set of kevlar belted tires, though.