Originally Posted by well biked
Wow, that sounds dangerous.
True. But on the other hand, I'm glad that Trek is trying to design frames that will take larger tires while still using regular (short) reach calipers. It's high time manufacturers pay attention to stuff like this. Another example of practical elements of Rivendell's design philosophy making it to the big companies.
Also, I know that Surly designed their Pacer frame (regular road bike frame) to work with regular (short) reach calipers, but at the maximum of their reach capabilities, so you can still use a 28c tire with fenders, 32c without. It's always struck me as ridiculous that road bikes using short-reach brakes aren't designed to use the full reach of the calipers, limiting you to 25c tires (which is the case with all three of my road bikes, although I suspect they'd take 28c tires if mounted on a wider rim - 28c tires mounted on a narrow rim will end up wtih a slightly larger outside diameter than if the same tires were mounted on a narrow rim).