Near wits end with 105 triple FD
 

I have a 105 triple FD with the stock cranks and rings that came with my '06 Felt F-80. Shimano 105 brifters on the handlebars.

Noting poor shifting performance up front, I've tweaked, removed, reset, reset, and reset (3 times from loose parts - no kidding) this derailleur and it still performs poorly. tried all sorts of cage angles, cage heights and cable tensions.

Symptoms: Going from smaller to larger rings works well in both cases. Coming back down not so much.

in order to avoid the cage rubbing I've successfully set the cable tension on the middle ring. I have the high and low limits set where they need to be, but when I downshift, it doesn't seem to allow enough cable back to the unit to fully move the chain down to the smaller ring. If i'm on the large one, i often have to go all the way to the granny, then back up to the middle. If i'm on the middle, I can't get it to go down to the granny if i'm on one of the 3 larger cogs (on smaller cogs it works OK due to the chain line)

Basic questions:

1. Is there hope, or evidence that this 105 triple FD works on other bicycles?
2. Will cage shaping possibly help me out?

thanks in advance for any advice/info you might give me on this frustrating problem.

There is nothing wrong with the design of the 105 triple front dérailleur. It will work well if set up correctly. Your problem may be due to hardened grease and dirt in the shifter. Try hosing out the shifters with WD40.
You may also need new shift cables and housings. Worn or dirty housings cause excess friction on the cable.

Try setting up the derailleur using the instructions found at www.parktool. com. The standard setup is the same for triples as for doubles.

Most Shimano road triple shifters, including the 105's, have 4 main positions for the 3 chainrings. This offers 2 positions for trimming each of the 3 chainrings. For the middle chainring positions 2 and 3 should be on either side of the middle ring, neither should be centered on the middle ring.

Is it possible you set cable tension without having shifter set on correct gear? My approach to setting front derailleur is as follows and works pretty much everytime:

1. With rear chain on larger cog in back and cable detached from front derailleur, set FD low limit screw so chain on smallest ring clears cage by about 2mm.

2. Ensure shifter is set on lowest gear, then attach cable to anchor bolt -- pulling cable taught but not excessively tight. Make sure cable routes to the outside of the tab on the derailleur body near the anchor bolt (this is critical, if cable is to the inside of the tab, derailleur shifting will be off)

3. Often no further adjustment is needed but sometimes slight adjustment is required by tightening cable using barrel adjuster.

With a triple, you may not be able to eliminate cage rub altogether when cross chained, but with trim adjumnet, you should be able to eliminate it in most gear combos.

shifting down before you are in the middle of the hill helps a lot.

Read the terrain.

FDs are very simple devices. Unless there is a lot of slop in the pivots, drag in the pivots, or a bent cage, they work fine. The 105 FD works as well as any. Assuming the proper crank and rings, after verifying the FD pivots, cage, and alignment is OK, the problem must lie with the cable/housings or shifter...or the operator's expectations and error.

You can't shift from the large ring to the middle ring? Perhaps the indexing in your shift is worn. Also pay close attention to the cable routing at the attachment point on the FD. I've seen shifting problems arising from cable wrapped around the pinch bolt in strange ways - make sure to follow the cable groove.

"1. Is there hope, or evidence that this 105 triple FD works on other bicycles?
2. Will cage shaping possibly help me out?" --ZManT

1. The 105 FD is a fine unit, one has worked for me for the last eight years, or thereabouts.
2. An old trick is to unscrew the rear of the FD cage and install a washer in between the two halves. This can help in cases where the shifter can't trim enough or for a variety of other reasons. It doesn't effect shift quality.

Brad

New cable, clear housings, and "flushed" brifter already (i've read the history on BF) - but thanks for those tips.

I'll take another look at the cable anchor - I recall it being fairly obvious where it should go, but this may yield fruit.

As for operator expectations, I expect it to work as well as the shimano cheapie on my flat bar bike, for which there is no complaint whatsoever.

Thank you for the helpful responses.

Is this a the 9-speed version of 105, or the 10-speed?

My DA Triple FD started acting up; downshifting issues. After some trial an error I found the FD cable hole that goes through the bottom bracket area had gotten gunked up and was binding up the cable. Once the hole was thoroughly cleaned out shifting was back to normal.

9 speed

Figures. I hate tuning these, but it can be done.

First, make sure the outer plate on the cage isn't bowed. If it is, squeeze the outer plate in with pliers. This outer plate can even be bent so it's a tiny bit concave. Next, set the cage on the seat tube as low as possible, with about 1mm clearance to the tall teeth on the big ring, and the outer plate is dead parallel to the big ring. This is so the bulge on the inside of the outer plate is what knocks the chain down to the middle ring.

Now adjust cable tension and limit screws as you normally would. It's a bit of a trick to set enough tension to hit the middle ring consistently but to avoid overshifting or hitting the derailleur on the crank when shifting up to the big ring.

The 10x3 versions of Ultegra and 105 were a vast improvement.

Try disconnecting the shift cable while in the middle ring. The FD should should drop down to the lowest ring. If it does your problem is likely in shifter/housing/cable. If it doesn't it's likely the FD. If the FD moves properly try pulling the cable out of its housing. Then while holding the cable test the operation of the shifter. If the cable moves properly in both directions its likely a housing problem or as already mentioned the guide at the BB is fouled.

You haven't said what crankset it is, except that is was stock on this bike. Therefore, what are the sizes of your chainrings? 9-speed 105 was designed for 52-42-30 rings IIRC. The size of the inner ring is not so important, but if the middle and large rings don't match these values then shifting is never going to be ideal (in fact, it is the difference between the sizes of middle and large ring that is the most important thing). I've seen several bikes with stock triple chainring sizes that don't match the stock front derailleur spec's.

I was under the impression that it was the middle/large ring that was important for proper functioning of a 9sp 105 triple FD and they need to be 52/42.


aside from the FD, how's the chain and chainrings? If they're worn out, then there's just no way to get the shifting perfect.

Resurrected thread - cool :thumb:
Crankset is FSA RPM 30-42-52

Chain and rear cassette are new and have less than 300 miles on them (as they were provided NIB to me when I bought the bike used 1 month ago)

I really doubt this is a cable or housing issue - I replaced the cable and flushed the one section of housing with WD-40, then put some Tri-Flow in it. It moves smoothly and cleanly within each of the (4) indexes for the shifter. It has to be a set up issue. I'll follow OldBobCat's advice and drop the vertical adjustment to 1mm, then I'll check the cage shape - I can see how a slight inward bow to the outer cage can help to downshift. My problem has consistently been the downshift with this unit - upshift functions flawlessly.

thanks again for the additional information folks -
Zman