Originally Posted by
kingfishr
I use 28/29mm on the Tarmac and 29/30mm on the Colnago Master. The Ridley takes max 25mm but I also use that bike mostly for racing. Panaracer Grand Bois and Challenge Parigi Roubaix mainly for 28-30mm. The width can vary by 1-2mm depending on the rim width.
I wouldn't mind trying 28's on my Focus but I have 25's and besides the fact that anything bigger would hit the seat tube I only have about 3mm of clearance to the inside of the calipers. I don't know how you guys fit tires that big on racing frames and short reach brakes.