I recall some of Freddy Maerten's 1976 team-issue Flandrias had this before just about anybody else in the pro cycling scene--but I have no doubt it has been around far longer in various forms (I also have a pix of Roger de Vlaeminck in the '72 Tour with another Flandria w/ under BB cables). By the late '70s some European framebuilders were putting the cables below the BB, and this was about three or four years before the mountain bike explosion was ignited in the early 80s. Also, more than a few US custom framebuilders were doing this during that same time too. The trend really took root since it showed, as others have written earlier today on CR, that the builder kept up with latest fashion-- er, excuse me, the latest frame *improvements*. Probably what most builders liked best about it was, as you correctly point out, it lowered production costs. Whatever the reason, it wasn't that unusual to see under-BB cables on road bikes before the big mountain bike impact.
FWIW, I brazed a lot of the cable guides onto the first batch of 100 Ritchey mountain bikes during 1980 and we put them on the top as this kept cable runs out of the crud and cleaner, plus the rear derailleur housing didn't have such a tight bend in it. But, as you point out, that soon changed as the move toward smaller chainrings got things moved under the BB in the next couple years. However, when this happened, that was emulating established road bike practice, it wasn't something that came out of the emerging mountain bike scene.
Bill "still like the cables on the top" Bryant Santa Cruz, CA
Sheldon Brown wrote:
> Brandon Ives wrote:
> >Something that I've always wondered about is when and why folks
> >switched to under the BB cable routing. I've always preferred the
> >above routing since the cables are shorter and put them more out of
> >the way of road grime, plus it gives the housing less bend and a
> >better line to the RD. I can understand for production that
> >drilling and tapping a 5m hole is much easier than soldering on two
> >hard to jig tiny cable guides. I would think many of the custom
> >builders would have kept it as a feature that was superior to the
> >way they do production bikes. So can anyone clarify the history of
> >under the BB routing and give me any good reasons to do it that way
> >beyond it's easier?
>
> I believe this is mainly a mountain bike innovation. I remember
> working on early MTBs that had above-the-bb routing, and having it
> interfere with front derailer adjustment. MTBs used smaller
> chainrings and big-cage, wide-range front derailers, and sometimes
> you couldn't get the derailer mounted low enough for good shifting
> without having the tail of the cage foul the rear derailer cable.
>
> Once this became the norm for MTBs, and it became clear that it
> worked OK and was CHEAPER, it was a no-brainer to extend it to all
> derailer bikes.
>
> This is a bit like the move from 36 to 32 spoke wheels. Usedta be
> that only very exotic time-trial bikes had 32. Thus, 32 spokes
> acquired cachet and manufacturers discoveret that they could save the
> cost of supplying and installing 8 spokes per bike and the customers
> would consider it a FEATURE! What a deal!
>
> The same thing is driving the move to threadless headsets...the
> manufacturers get credit for "higher performance" and get to save
> considerable spondulix.
>
> Sheldon "Spinning The Cut Corners" Brown
> Newtonville, Massachusetts
> +--------------------------------------------------------+
> | Several excuses are always less convincing than one. |
> | --Aldous Huxley |
> +--------------------------------------------------------+
> Harris Cyclery, West Newton, Massachusetts
> Phone 617-244-9772, 617-244-1040, FAX 617-244-1041
> http://harriscyclery.com
> Hard-to-find parts shipped Worldwide
> http://captainbike.com
> Useful articles about bicycles and cycling
> http://sheldonbrown.com