Help on FD adjustment

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Help on FD adjustment

Postby stryker84 » Sun Jan 13, 2008 3:52 pm

Okay, I've got a Sora triple FD...

(patiently waits for the laughter/derision to die down)

... on my flat bar. Have been weaking the shifting, and I can currently get it to shift smoothly all the way down, and up from small to middle. However middle to large requires me to actuate the lever once to get it to the 3 position (chain/derailleur rattles), then push it in again slightly to get that last bit of cable tension before it shifts up.

So it's a minor problem, it's not like it's refusing to shift at all, it will always shift up fine, but it needs a push and a half before it does that. Any tips on how to remedy this?

And no, I'm not gonna bin the Sora and get a real derailleur. :roll:
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by BNA » Sun Jan 13, 2008 4:00 pm

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Postby europa » Sun Jan 13, 2008 4:00 pm

It's not the dr, it's the shifter OR it's the REAR dr adjustment.

First off, fire up Park Tools and adjust the front and rear dr. Interestingly, the majority of front shifting issues are cured by adjusting the rear dr (I've proven this soooo often). Note that you need to be looking at the limit screws, the cable tightness AND the position of the front dr. Generally, front drs are set up far higher than people like Park Tools or Sheldon Brown advocate.

Now that you've got it working properly, you may indeed find that you need to push the lever right over and hold it for a moment to get a clean shift. If this is the case, you're effectively overshifting slightly to get the chain across and then allowing the dr to drop back to it's 'drive' position. I run Ultegra shifters and find that when everything is fine, just a press of the lever is all I need, but when things are getting marginal they need that little more help.

Of course, the Europa has no trouble at all :roll:

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Postby Hawkeye » Sun Jan 13, 2008 5:47 pm

+1 for Richard's comments. I find I have to overshift ever so slightly and hold momentarily to get it to go up to the big ring, and I now do it without thinking about it. The top limit screw is set to allow this without pushing hte chain off altogether.

That said, FD's can be tricky beasts and in addition to your issue I had a lot of problems with my chain jumping off altogether when downshifting from middle to granny ring on the front.

The solution had three parts:
1: Move the FD down so that it is positioned according to the manufacturer's tech sheet, downloadable from their english-language website
2: Make sure that the chain is the right length, and not too long. That means just long enough to loop from big chainring and big cassette cog only, + one inner-and-outer link pair.
3: Careful adjustment

Occasionally I'll get chain snatch if the chain is overdue for a clean. This usually bends the DR cage up ever-so-slightly, just enough to make shifting down unreliable. I just use a large pair of multigrips - with the jaws lined with a thick piece of rag to avoid marking hte metal - and gently bend it back.

I've also got a 3rd-Eye Chainwatcher for a bit of extra insurance against jamming on the commuter. My dual-suspension offroader doesn't seem to need it.
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Postby LuckyPierre » Mon Jan 14, 2008 7:24 am

I find front derailleurs to be the trickiest to tune fully (touch wood, they're all working well at the moment). As the others have said, if you've set the derailleur according to the installation instructions, then tested your cable tension (both on the stand and on the road), you should be right. If you're still getting some lag going up, then try moving to higher gears (smaller sprockets) on the rear before going to the large chain ring.
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Re: Help on FD adjustment

Postby heavymetal » Mon Jan 14, 2008 9:14 pm

stryker84 wrote:Okay, I've got a Sora triple FD...

(patiently waits for the laughter/derision to die down)


:lol: :lol: :lol: :lol: :lol: :lol: :lol:

So have I until my new Deore LX arrives later this week. The best thing you can do with it is throw it in the bin :shock:

stryker84 wrote:And no, I'm not gonna bin the Sora and get a real derailleur. :roll:


Woops sorry, didn't see this :D

As suggested above, try pushing it down but watch out that the end of the DR cage doesn't hit the chain stay when on the smallest chain ring.

The problem with this FD is that the cage distorts and bends when changing gears.

The best improvement I found with the Sora FD (after belting it with a hammer) was to twist it so the FD was at an angle pointing towards the centre of the rear wheel. (over exaggeration, but it gives you an idea which way to twist it).

By doing this when changing up, the raised bit on the inside of the FD cage contacts the chain earlier, resulting in better changes. When going down, the outer edge contacts earlier as well.

If you do twist if off centre, you will have to readjust the cable and gear shifter. I'm using mine on friction shifters, but before it was hooked up to Sora brifters. It was even worse then

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Postby Mr888 » Mon Jan 14, 2008 10:07 pm

Kev beat me to it. I was going to recommend that angling the FD too (ever so slightly). Worked well when I was using the Sora set up many many years ago... 8)
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