On 01/24/2011 05:03 PM, donald gillies wrote:
> A friend of mine in 1982 told me that TREK was trying to be innovative
> and save time in their frame manufacturing. In 1985 I bought a TREK
> 500 bicycle which not only had the 1-piece I.C. headtube, but also had
> a pretty cool bottom bracket that routed the cable into the bottom
> bracket shell and then inside the right chain stay and out of the
> dropout plugs, through a cable, straight to the derailleur - no
> rusting for the last 30 inches of cable run, and no needless friction
> either! Also those bikes had a cinelli-copy 1-piece seat cluster, too!!
Yes, the 1985 5xx and 6xx series frames used a one-piece cast head tube. A cast-in shoulder inside the lug allowd us to use a straight-cut (rather than mitered) tube end, which facilitated manufacturing. I was never particularly fond of this design, as the cast head tube was much heavier than either a 3-piece lugged head tube or a bulge-formed one piece head tube.
The internal cable routing was interesting, and I had the task of creating and maintaining the tools used to install the plastic cable guide inside the right chain stay. This was a plastic insert that guided the cable to the exit hole in the drive side dropout. The tool I created and maintained was a brake cable to which the threaded end of a spoke had been brazed. A short piece of seat stay tube comprised the handle by which the assemblers would install the internal cable guide.
The assemblers would thread the tool cable through the drive side dropout into the bottom bracket, put a plastic cable guide on the tool's cable and a spoke nipple to hold it in place, then pull the tool cable firmly through the dropout to seat the cable guide and then remove the nipple to extract the tool. We tested placing multiple cable guides into a chin stay to ensure that this would not be a problem, and it wasn't.
Every couple days I would have to recreate the tools when the spoke end became detached from the cable.
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-John Thompson (john@os2.dhs.org)
Appleton WI USA