It doesn't matter anyways. Touring bikes evolved as a purpose built offshoot of the roadbike community. I started touring with a late 70's Raleigh Grand Prix with Blackburn Racks and red Cannondale bags. I thought that 2x5 setup was pretty good and the bike did everything I wanted it to do. Flash forward to last year and you would find that I upgraded my Cannodale T1 drivetrain from a 3X10 sport touring setup to a 3x9 touring setup. But I made a small, but not worthwhile changing, mistake. I kept to the roadbike theme of my youth and didn't take into account of where I think future touring bike drivetrain influences will come from.

In my opinion, touring bike drivetrains will be more influenced by the mountain bike community. If I was upgrading the T1 drivetrain today, the 13-36 9 spd cassette plus Deore shifter would remain but the crankset would be replaced with a 38/24 9 spd trekking double. Well not quite. I would probably put the 12T cog back on the cassette.

The 2x10 mountain drivetrain is fantastic. Ask anybody who has tried one out. It's the future for both mountain biking and touring. But that's only my opinion. I'm riding a triple and it works quit fine and I'm certainly not complaining. Al