I've got the S-Works model. Absolutely love it. I reckon you could fit 32mm tires on there at a stretch. I have 28mm GP4000s fitted and they measure about 30mm--still room. Mine comes in at 6.9kg with Dura Ace Di2. I looked at the new Venge but I don't race anymore and this just seems like a more versatile bike.

FWIW, I have the non-disc SL6 Ultralight and ride the Turbo Cotton 26Cs on it, with plenty of room to spare. My Tarmac SL4 rides 28C tubeless with no problem.

Ian

I have the pro disc version, it’s awesome, just got it a month ago. It is indeed light, fast, and responsive, as advertised. I am coming from 2009 Madone 4.7, which I think has similar geometry to the R3, so you may find the following comments helpful. One of the first things I noticed riding home from the bike shop is that compared to my Madone the steering is more responsive, or twitchy, depending on your perspective. It took a bit more concentration at first to keep the bike straight, and riding no hands is not as easy as it was on my Madone. I also find it faster, especially going downhill, and I attribute that to the aerodynamic features. The flexible seat post works very well, and absorbs the road buzz in the back. I do feel more road vibration in the front, although I have recently been told that I am over inflating the tires -- they are 26 mm, I am 150 lbs, and I’ve been inflating them to 104, whereas I’ve been told 80-90 is what I should be inflating them to, so I’m looking forward to trying that. It is a fantastic bike if you are interested in a fast road bike with aggressive geometry. Although it accommodates wider tires, I am not sure it would be such a good bike if you are primarily interested in riding on uneven surfaces or gravel, just because I think something with more stability and less responsiveness might be better on such a surface.