I think it's a 2011, it's the first year the frame used BBright.

I just mounted my last spare tire on my rain bike, and need to order more. I've been thinking about trying 25s, since I've been running 23s for years. Better comfort shouldn't hurt, and it seems like they'll have a little bit better grip through tight corners coming down mountain roads.

When I got the bike, LBS told me clearance for bigger tires was dicey, and it depends which particular tires.

Any experience with this?

I can't answer the question about clearance, but I can say that I have 23mm on one bike and 25mm on the other (both GP4000s) and can't really tell much difference. Of course, I already ride lower pressure (95 psi give or take 5 at 200lbs). Both ride great and I've never had any grip issues (though I doubt I push them to their limits). If 25s would fit might as well try it as it can't hurt but might not notice much either.

I would be surprised if any modern road bike didn't have enough clearance to accept 25mm tires.

I like 25s on my S1, but they were rubbing in the back, so I took them off (it was occasional rubbing only). I'm not exactly built like a GC contender, though (~180lbs, maybe ~165 mid-season, after lots of racing). The rubbing was on one of the brake lever arms, not the bridge itself though, and the new ones I got might allow it. It WILL be tight to run 25s on a Cervelo, I promise you, but 23s on their tri bikes are tighter than 25s on their road bikes. Not sure why roadies want more clearance.

My experience is based on the 23mm Belgium rims, FWIW.

I ran 25mm GP4ks on my 2010 RS. The fit was pretty tight but it worked. If you have the same 3T fork I think you'll be OK.

Might want to search over on Cervelo's official forum:

https://forums.cervelo.com/forums/5.aspx

I have used 25's on my 2007 and 2012 R3 with no problem. I don't think there is any noticeable difference though between 23's and 25's. I usually just buy whichever ones PBK has on sale.

Depends on the tire. I know for a fact that I can not run a Michelin 25 on:

Aerocat 509
Salsa Podio
Giant TCR Advanced (2012)
Giant TCR Composite (2012)

So....yeah....lots of modern frames can't run 25's. The issue is who makes it. Conti makes a "small" 25. Odds are it "should" clear.

My buddy at my LBS couldn't run 25's on his R3 because it didn't clear.

tried pro3's, pro4's and 4000s. none of them worked.

Good to know, thanks Rob.

The Continental GP4000s 23s are more like 25s. They barely clear the brake pads on the Ultegra brakes without a little gentle nudging..