Dura Ace 7800 left shift, broken? :-(

unixnerd

Just bought some used Dura Ace 7800 triple/10 speed shifters and the correct harness for the FlightDeck computer. All seemed to work just fine (including the interface to the computer) until I tried hooking it up to the front mech (also DA7800).

At this point part of the brand new front cable outer's metal liner got pulled into the shifter! Never seen that happen before and it took a bit of force to remove it. Shifting the left lever both without and with a bit of cable tension then became a bit unpredictable although after a few cycles from big ring to little ring it seemed OK. Mechanically it seems to be OK now but it the computer thinks it's permanently in the little ring. Wiring is OK as I can use the left button to advance the lap counter, so it must be something in the shifter.

Any idea before I strip it all down? Thanks in advance.

baznav73

You will have to take the shifter apart and have a look.

timmyturbo

there is a much better link out there than this , i cant find it at the moment , if you are going to BIN IT , you have nothing to lose by trying to fix it really ??

http://www.norvil.net/pedal/service/shi ... /index.php

unixnerd

Well I partially disassembled the lever and for the bit I did it wasn't as bad as I thought, but then I'm an engineer and have all the right tools. Slackening the main bolt on the gear shift assembly (8mm I think?) then working the shifter back and forth a few times and putting it back on gently has restored mechanical function and the bike shifts gear just fine.

Sadly the the electrical portion is doing nothing and the computer thinks it's in the bottom ring all the time. I can live with that for now, all it does it put the cadence reading out. Will keep my eyes out for another used shifter and then sell this one to someone who doesn't need the computer interface to work (which would be 99% of folk I reckon!).

There are better ways to spend a dry Sunday afternoon......