Installing 105 STI

[keith]

Hi guys my left 105 STI gave up on me so I've bought a new set. The question is how do I uninstall my broken one I have now, and install my new one? I've had a good look and don't know which screws to turn to release the cable. I've done tons of searches on the web with no joy. I want to try do this myself and learn, without having to take it to my LBS. Thanks ahead!

[Johan Bornman]

It isn't trivial and not really suitable for a short explanation but I'll try.

 

 

1) Pull the rubber boot on the STI, from both sides, up onto the STI so that the handlebar part is exposed.

 

2) Remove the handlebar tape and if it is salvageable, only undo it up to the bottom of the clamp and let it hang there.

 

3) Release the gear so that the chain falls onto the granny gear.

 

4) Cut the gear cable off and ditto for the brake cable. Your instinct will tell you to try and save it. I say don't bother. With long pieces of cable in your hand it is easier to get to tension and you won't be stung by cable ends.

 

5) Pull the brakes, look into the gap opened by the lever and notice the head of the brake cable. Push on the brake cable from one of the exposed parts on the bike and notice the head wanting to poke out inside the STI. Take a long nosed pliers and persuade it to come your way whilst pushing on the cable. It'll come out. Pull it out all the way.

 

6) Now push on the gear cable towards the STI and notice where its little head pokes out. Memorise the spot and remove the cable completely.

 

7) Now take a 5mm allen key and loosen the clamp that holds the STI on the handlebar. I suggest you use a koki to mark its position first. You'll find the clamp bolt (I'm doing this from memory now so the exact position may vary) by pushing the 5mm allen key between the STI body and the Rubber hood, at a position marked with some sort of notch. This notch will be on the outside of the STI i.e. in your case on the far left side against the vertical wall of the STI's pedestal. Undo the bolt and slide the STI off via the bottom of the handlebar. Ooops, I forgot, the tape may still be on there. Maybe you can undo the clamp completely and just use the old clamp on the new STI - you'll know what I mean when you get there.

 

8) Assemble everything in reverse.

 

9) Make sure the brake and gear cables are pushed into the STI slots as far as possible and secure them to the bar with some insulation tape.

 

10) Don 't put the bar tape back yet. First see if you can thread the new cable (now you'll thank me for speccin'g a new cable) through the appropriate hose and get them to slide into the cable housing.

 

The nbew STI has to be in the small blade position for you to get access to the cable recess.

 

If they don't want to slide it and get stuck somewhere, remove the housing from the STI, push the cable through and then slide the housing over the cable.

 

11) WATCH OUT! If you allow the open lever (as in the braking position) to close on a half-in cable, you will ruin the cable and possibly require surgery to remove the cable. Thread the gear cable all the way in in one go. Don't be tempted to keep it half threaded. Campy users don't have this worry.

 

12) Set the gears, replace your bar tape and go for a test ride.