I don't get how discs are necessary to enable fatter tires. My Lemond 'cross bike has a huge clearance for tires, as do my TRP mini-Vs. BTW, the TRPs are fantastic stoppers, better than any mechanical discs I've ever used.

I can skid the rear wheel on dry pavement, or raise the back of the bike off of the ground if I clamp on the front brake. I think that is enough braking power.

I also don't get the fat tire thing. Sure, weekend warriors in the First World are getting fatter, and more club-level riders are on clinchers (vs. tubulars), which was not the case 30 years ago. Both of this means riders need bigger tires for impact and pinch-flat resistance.

But if you are riding tubulars, which are pretty much immune to these problems, you can realise the benefits of smaller, lighter tires and rims, and still ride at relatively low inflation pressures.