Joined: Feb 2012
Posts: 19,288
Likes: 5,382
From: Rochester, NY
Bikes: Stewart S&S coupled sport tourer, Stewart Sunday light, Stewart Commuting, Stewart Touring, Co Motion Tandem, Stewart 3-Spd, Stewart Track, Fuji Finest, Mongoose Tomac ATB, GT Bravado ATB, JCP Folder, Stewart 650B ATB
For the factory (or builder) drilling a hole in the bottom of the BB shell to fit an outsourced cable guide is vastly faster, thus cheaper, then brazing on a pair of above guides. There's nothing wrong with above guides if they are well placed. If poorly located the cables can rub on the tubing surfaces though.
If the frame is used and already has the above shell guides then by all means use them and be happy. IIRC the last time I brazed on a set of above guides was in the mid 1980s. Andy (Who has a few pairs in his stash slowly rusting away)
__________________
AndrewRStewart