I stand corrected on the set of 32mm clearance spec road bikes. There's at least one important addition: the
Venge, per two review sites (not independently confirmed). Very interesting!
Cycling Weekly claimed that their
Foil test bike 28mms with actual width = 30mm fit, and that it appeared that anything up to 35 mm might fit
Per quick Internet research, here other tire clearances. Some are based on manufactuer official claimed numbers. Of course actual measured widths are the better metric than the ERTO spec number, and actual widths can vary depending on the rims -- my list here does not purport to be precise in the real world.
Propel -- 28mm
TCR -- 28 mm, there's a colloquy on this on this site...even the industry wide leader Continental 4000 fit at size 28 mm
Teammachine and
Timemachine -- 28 mm
Aeroad -- two sites claimed 28 mm and some 30 mms will fit
R5 -- Cervelo says up to measured 30mm width
S5 -- per a site, "Cervelo claims the S5 will swallow 30mm tires with ease, while the S3 has been optimised for 28mm tires."
Madone -- per Velo News, "Officially, you’ll be able to fit 28mm rubber in there, but there’s plenty of clearance to run a larger tire. 30mm for sure; 32mm is a possibility"
Emonda -- posters on this site already figured this out, 28 mm
SystemSix -- Bicycling mag reports: "Cannondale designed this bike with 26mm tires in mind and claims the bike can officially accept 28mm models. Unofficially, it also fits some 30mm tires."
SuperSix -- 30 mm. I'm sure Damon Rinard knows the exact details and can explain if needed
Dogma F12 -- per Pinarello as quoted by Bike Rumor, "...the Dogma F12 and F12 Disk are designed to accommodate 28mm tire clearance. In reality the tire clearance is 37.5mm, however we have included consideration for the ISO 4210 norm, which specifies 4mm space between the tire and frame. Analyzing several tire and rim combinations we have given a declared value of 28m. In reality a declared 28mm tire can have a real width of 29.5mm. That’s the reason why the frame has been designed with 37.5mm clearance. This allowed the F12 frame to be compatible with all the most aerodynamic wheels that has a 30mm width.”
C64 -- true clearance on rim = 36.5 mm = fits most 28 mm tires; Colnago said a bit more on the disc
Helium -- 28 mm official
Noah -- Canadian Cycling site opined it looked like up to 30 mm actual could fit based on 25 mm on test bike
Gallium and
Nitrogen -- 28 mm
Xelius -- 28 mm (can't figure out the
Aircode)
Scultura disc -- 25 mm per road.cc, but Bahrain-Merida site says 28 mm
Reacto -- 28 mm
Alfa disc -- 30 mm
Would 28mm have been almost unanimous 5 years ago? The majority, as recently as 3 years ago? Interesting.