'92 GT Tequesta cable routing gone awry

tharvs

Retro Newbie
Hi everyone!

I am in the process of trying to resto-mod a 1992 GT Tequesta in the lovely black crackle paint colour. It had been going well until now when I have developed a slight issue. Apologies if this is a rookie error but feel free to chortle at my expense!

A slightly misguided attempt to lead a new rear brake cable through the internal cable routing in the top tube has resulted in some electrical tape becoming lodged in the cable path, blocking the cable from passing through. The 92 model has internal routing that uses at an internal cable stop which presumably leads through to some internal pathway to the exit just in front of the seat tube.

I can push the tape to the entrance by reverse threading a cable from the back, but the aperture at the entrance end is barely 3 mm across and so even my finest tweezers aren't able to gain access. Does anyone have any suggestions for how to deal with this? At the moment my thoughts would be to drill out the internal cable stop to a wider diameter to try and hook the tape out through, but if anyone has any bright suggestions I'd love to hear that before I do something drastic! Happy to supply any details I have skated over if need be too.

Thanks in advance for any help/suggestions, it's much appreciated!
 

Corduroyboy

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Piece of stiff wire? Cable is great under tension but not much use under compression. Wire ought to do the trick if you can find some which is under 3mm but bendy enough to follow the cable routing. I can imagine the frustration when the tape got lodged inside!
 

ishaw

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I've got a trick for this which I honed when I had a gt sts. Basically unwind a wire coat hanger and bend it to suit and feed it through the frame.

Next I feed over the top of the hanger some inner cable sheath (or electrical wire outer) until that pokes out both ends.

Pull the hanger out, feed your cable through and remove the cable sheath.

Jobs done
 

tharvs

Retro Newbie
Piece of stiff wire? Cable is great under tension but not much use under compression. Wire ought to do the trick if you can find some which is under 3mm but bendy enough to follow the cable routing. I can imagine the frustration when the tape got lodged inside!
I've got a trick for this which I honed when I had a gt sts. Basically unwind a wire coat hanger and bend it to suit and feed it through the frame.

Next I feed over the top of the hanger some inner cable sheath (or electrical wire outer) until that pokes out both ends.

Pull the hanger out, feed your cable through and remove the cable sheath.

Jobs done
Thanks for the suggestions - if it's worked before this sounds like a solid plan. I wasn't sure if this would work as the whole reason I originally needed to reverse route a cable from the back was because when I tried pushing the cable from the front it kept hitting something and getting stuck - hopefully the wire is stiff enough to follow the routing!
 

tharvs

Retro Newbie
Update on this - tried the wire trick and no joy! Turns out that wire coat hangers have too high a diameter to fit through the rear, internal cable routing! As a result I can't feed the wire through in either direction and I don't think the tape will fit into the rear cable housing either!

So - is the drill plan likely to compromise the structure of the frame? If the answer is a resounding yes - does anyone have any suggestions for external clamp on bosses and cable routing? 🥲
 

tharvs

Retro Newbie
How far from the end is the tape stuck?
Probably in the 3-4 cm from the front end - the boss is a ~12 mm diameter tube that extends into the top tube, terminating with a smaller aperture (~3mm) than the entrance to the top tube. The tape is just beyond this aperture - the routing doesn't seem to be a coherent passage from front to back.
 

Iwasgoodonce

Old School Grand Master
I would try everything before drilling anything. Get some thinner garden style wire. I would be tempted to try and melt through the tape by heating the wire. You won't need much temperature to get through tape.

What diameter wire would fit down there? Mig wire? Piano wire? Mig wire will hold a bend nicely and is available in many thin diameters from 0.6 upwards.

I had a similar issue with my Saracen. Luckily, the internal tube took the cable outer diameter so it wasn't as bad.
 

tharvs

Retro Newbie
To wrap up this issue, a quick explanation of the solution we got to! By maintaining the reverse pressure on the tape by pushing a cable through the routing from the back, we were able to fashion an auger of sorts out of wire and rip up/pull out enough of the tape to lasso the cable and successfully reverse thread the brake cable from the back.

However (!), the solution wasn't as simple as sliding cable sheath over the reverse-threaded cable to guide it through the frame. The diameter of the cable sheath (which was extremely thin) was too great to fit into the internal cable routing set-up from either end. What worked in the end was using a ~20 cm section of cable sheath and sliding that onto the cable at the front entrance, pushing this as far into the frame as I could before it was obstructed by the internal routing. Pushing the new cable through this sheath so that it directly followed the reverse-threaded cable was enough to align it to the internal routing and I was then able to push it all the way through. I could then use a scalpel to cut the small section of cable sheath off the cable and hook it up to the brake (jubilant hooting all round).

This was probably not the easiest way to go about this. It was a fairly stupid problem to make for myself (which I won't be doing again) but if anyone else does the same thing, then that was our solution!

Thanks for everyone's suggestions! :)
 
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