Flightdeck problem

[Camilo]

Hi: I've been using a flight deck computer on my Ultegra 9 speed bike and it has always worked perfectly. I recently installed a unit on my daughter's 8 speed Sora bike and am having a problem with the left side contacts (I believe).

The computer works perfectly for every function except the gear indicator for the front chain rings (triple).

I have it programmed correctly for a triple, 8 speed. I've double checked.

The gear indicator display shows three positions for the front chain rings, but won't register the middle ring. The indicator display shows the large ring when the chain is on the middle or large ring. It shows the small ring when the chain is on the small ring. In other words, it doesn't "know" when the chain is on the middle ring and "thinks" it's on the large ring.

I've opened up the shifter/brake hood and removed the sensor piece. I've cleaned all of the contacts with electronic contact cleaner. I've tried more shims and less shims (which I have had to adjust on my other bike, so I know how to do it).

I've tried a different computer head that I know works, and have changed the battery. Same symptoms.

My conclusion is that there is a problem either in the contacts in the shifter itself, or in the corresponding contact that is wired to the computer. If it's the contacts on the wiring harness, that's a relatively easy fix. But if in the shifter itself, I'm wondering if there is a part that can be replaced or if I'm screwed.

Does anyone know how to trouble shoot this? I have a multimeter and know how to use it!

Thanks for any advise you can give

 

[alfeng]

Does the cadence/whatever change, accordingly, when the chain is on the middle ring OR is FlightDeck calculating as if the chain were still on the large ring?

What happens when the chain is on the granny? Is the indicator on the display correctly showing the granny OR does it indicate the middle ring OR is the indicator still showing the large ring? AND, are the calculations subsequently for the granny OR middle ring OR large ring?

OR, is it only the superficial indicator on the FD display that isn't working correctly that concerns you?

FWIW. Since it's been a few years since I looked at a FD ROAD harness & the "receiving bay" in the lever body ... are the "tines" in the lever's body "flush"/FLAT or can they be tweaked?

Although you've cleaned the superficial contacts between the base of the Sora brake lever & the FlightDeck "insert" that fits in the lever body with a contact spray, have you tried the more mundane method of using the eraser on the end of a pencil to clean the contacts?

That is, are you sure that they are ALL actually making contact?

If you are certain that contact is being made, then I reckon the possible resolution would be to "dip" the lever into an "sonic"/ultrasound cleaning bath (OR, as a last resort, "boiling" water -- 100º C shouldn't be a problem, but ...) because the contamination/problem is situated where you probably can't otherwise access it ...

Personally, if it is ONLY the gear indicator AND NOT the calculations, then I wouldn't worry about it ... BUT, I only use the minimal number of functions on my FlightDeck because it has been connected to a "universal" harness (I'm using Campy shifters) for years ... so, the lack of the gear indicator is the least of my concerns.

BTW. Since you apparently have a GOOD left lever (even if it is only a double), the easiest way to troubleshoot WHICH tine may not be making contact would be to one-by-one cover the contact on the harness's insert, and see which exclusion causes the display "failure" to occur. Of course, if "covering" a single tine causes a complete failure, then the problem isn't with the contacts.

 

[Camilo]

Thanks alfeng - I'll check those things out this weekend. I might also swap the wiring harness with my own to see if it follows the harness - but your tests and procedures will probably get me the same info.

 

[Camilo]

I decided it was a better use of my time to give up and buy a new harness. Sometimes you just throw parts at it as the path of least resistence. Works perfectly now without as much as a shim or tweak.