Luiz-Oahu

Hi, I've had my road bike (Cannondale) for sometime now, but there is something that is bothering me. When I change gears my front derailleur is not very precise. I mean, sometimes I change to the small chain ring and it doesn't go, I have to change gears twice in order for it to go. Same thing going up.

My question is, since I have only two chain rings in the front, is it possible that I have the wrong front derailleur? I mean, one for three chain rings? Or is it just a matter of adjusting?

Thanks, and sorry for the newbie question.

Luiz

SoonerBent

Some Shimano , 105 for instance, are made to use with double or triple. No other option. On these there is a trimming function for the middle chainring of a triple or the large chain ring of a double. So, in order to make sure you miss the trim position and shift all the way to the other chainring you have to make sure you move the lever all the way over.

SB

55/Rad

Which der do you have? What shifters do you have? How many speeds are you running? Exactly what model is your chain?

FormerBMX'er

I'm gonna go out on a limb and say you have some cable stretch and therefore are half-shifting instead of dropping to the small chainring. You should be able to dial this out with the adjustor on downtube or take it back to where you bought it and have them tune it.

C4Byke

speaking of which, who here thinks it's more of a pain to adjust the FD than the RD? I can never get it right

grinderbob

front d is just a piece of spring loaded components, it cannot be wrong by itself. The only adjustment
is how far it can pull or retract on each end. It is more of a shifter (half shifting vs
full shifting), and cable tightness issue. You can try fine adjusting the cable with the cable stop.

ggg300

Like rad/55 asked^^^ ????

parktools.com

Luiz-Oahu

Thanks for the answers so far. My shifters are ultegra, and the front derailleur is 105. Since I have only two rings I thought one touch would bring the chain down, but I need two, and two to go up, that's why I suspect I have a derailleur for three chainrings.

Waldo

No, the shifter has "trim" positions that allow you to move the chain in small incriments to reduce chain rub on the derailleur as you increase the chain angle (between front ring and rear cogs). Sounds like it is working as intended. Visit Shimano's website or return to the place you got the bike-they should have explained that to you when you got it.

simplyred

+1

That's the new 10 speed Shimano if I'm not mistaken.

Luiz-Oahu

I have the old 9 speed.

huytheskigod

I have the 9-speed ultegra shifters as well. The left shifter is designed to work with both triple and double setup. When using it for double, the front derailleur adjustment will lock out operation to the third ring. regardless, what others have said is correct. There is a built in trim "click". There are two "clicks" for either downshift or upshift. You have to push both clicks to get into the big ring. When you're in the big ring and lower gear combination(larger cogs) the chain will often rub the inside of the front derailleur. This is when you can downshift one click with the left shifter to "trim" the front derailleur to stop the rubbing. One more click will then drop the chain the the smaller chainring. It doesn't sound like anything is wrong, just that no one ever told you how the shifting mechanism worked.