Reload this Page top pull front derailleur very difficult to shift onto large chainr



horizon

New Member
Mar 15, 2007
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front derailleur - shimano lx gold top pull
shifter - shimano deore dual control levers

everything hooked up and tight, cable lubed inside the casing, derailleur moves fine and free with fingers.

this is how the cable is attached to the derailleur, click for larger image, yellow line is cable.



coming from the top, lopped under the bottom guided by a groove in the body of the derailleur, bolted down when it comes around and is on top.
 


is this a top pull derailleur? the type that accepts the cable from the top? this is the derailleur i have. click to make larger
 
horizon said:


is this a top pull derailleur? the type that accepts the cable from the top? this is the derailleur i have. click to make larger

I think that is a bottom pull. See that groove immediately below the wire clamp screw in the pic? It really looks like it's meant to house a wire pointing downwards.
It might be a dual-pull though, I've never seen one of those IRL.
Does the cage move OK if you unhook the cable and push/twist at the der with your hand?
 
horizon said:
yes, the derailleur moves freely when moved with a hand.

Will it shift OK when you move the der by hand?

You MIGHT have stuck the der too close to the chainring. If you look at the bike from the side there should be something like a half-inch gap between the der cage in its outward position and the top of the teeth of the biggest chainring. Adjusting the der position along the seat tube might help.

It might also be that you have the limit screws set too tight, the der cage has to be allowed to overshoot some for the chain to drop into place.
 
END, i bought a new xt derailleur and have to take apart the chain to get it threw the cage.
 
horizon said:
front derailleur - shimano lx gold top pull
shifter - shimano deore dual control levers

everything hooked up and tight, cable lubed inside the casing, derailleur moves fine and free with fingers.

this is how the cable is attached to the derailleur, click for larger image, yellow line is cable.



coming from the top, lopped under the bottom guided by a groove in the body of the derailleur, bolted down when it comes around and is on top.
Well, this is apparently AFTER-THE-FACT since you have purchased a new front deraillur, but to state the obvious, that WHITE PLASTIC protrusion is there to facilitate assembly in the factory and should be removed.
 
dabac said:
You MIGHT have stuck the der too close to the chainring. If you look at the bike from the side there should be something like a half-inch gap between the der cage in its outward position and the top of the teeth of the biggest chainring.
Shouldn't be 1/2 inch, should be 1-3mm.
 
artemidorus said:
Shouldn't be 1/2 inch, should be 1-3mm.

Ah, well. Didn't have a bike available for reference and tried to remember the size of that assembly guidance sticker that sat on the cage on the last FD I handled new out of the box.
 
horizon said:
END, i bought a new xt derailleur and have to take apart the chain to get it threw the cage.
You CAN do that, but there's also a screw that allows you to open the cage.
 
dabac said:
You CAN do that, but there's also a screw that allows you to open the cage.
Not on the current XT models; they're riveted. It's a right pain in the ****, as I discovered last weekend. Luckily, I had a Connex link in the toolbox.
 
horizon said:
front derailleur - shimano lx gold top pull
shifter - shimano deore dual control levers

everything hooked up and tight, cable lubed inside the casing, derailleur moves fine and free with fingers.

this is how the cable is attached to the derailleur, click for larger image, yellow line is cable.



coming from the top, lopped under the bottom guided by a groove in the body of the derailleur, bolted down when it comes around and is on top.
You had the cable attached correctly - that model is for top or bottom pull. For bottom pull, the cable goes straight down from the attachment bolt. Maybe your upper limit screw is too far in?