Originally Posted by halfspeed
Because the best argued case available for wheel durability supports the idea that butter spokes are better, regardless of any weight savings.
Spreading steel frames from 130 to 135 mm is not the big scary surgery you seem to fear. It's a common procedure and it works well. If spreading to 135 really makes you nervous, go to 132.5 and fit both 130mm and 135 mm hubs. Two and a half mm is about the thickness of a pair of dimes. Don't sweat it.
The OP is building a wheel for touring, I presume fully loaded. In that usage, wheel strength is paramount. MTB type hubs are more weather resistant, more durable and have less dish making an all-around superior assembly. Yes, you can tour on road hubs, but why bother when you don't have to?
Well said. I've got a very nice touring bike from 1983 (Centurion Pro Tour), it's got a 40-spoke rear wheel with a freewheel hub and 126mm rear spacing. As nice as the bike is, that hub is the weak point of the bike (it's the freewheel aspect that makes it especially weak). For touring, go for the strongest rear wheel you can realistically put on there (less dish, 36 spokes at least, cassette hub). These days, that means a "mountain" cassette hub spaced at 135mm. They're not popular with tourists for nothing.
I just respaced my '83 Schwinn le tour luxe frame to 135mm, I'm switching to wheels with "mountain" hubs. I had respaced from 126 to 130 a few years ago so that I could easily use a modern cassette hub, and I'm finally putting wheels on the bike that will better match what I use it for-