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Sofa King We Todd Did
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Quite simply, I'm having problems with my front derailleur, getting it to shift from the middle chainring to the largest one. These days I'll shift the lever, the derailleur with move, but the chain with stay on the middle chainring while rubbing away at the derailleur cage. Random acts can temporarily 'rectify' this problem and shift the chain over - stop pedalling and start again, shifting to a smaller cog in the rear, that sorta thing.

I've meddled with the H-limit screw a bit. I've unscrewed it quite a bit in hopes that this will bring the cage outwards a bit more when I'm upshifting so that it'll help pull the chain out to the largest chainring, but that hasn't helped too much. I've lubed the chain a couple of times now. I've even tried tugging at the derailleur cage. And I've tried reading up the repair help section at Park Tools. All to no avail.

A quite bit of background - I had nasty crash about a week ago that slightly bent the rear derailleur to the point that when I tried shifting to the largest rear cog, my chain would get dropped. In that time, I've bent the rear derailleur back and everything shifts quite cleanly now. Now the front is giving me problems. Could my front derailleur problems be caused by my rear derailleur? I ask because I know that almost nothing works independently on a bike and that "the hip bone's connected to the leg bone, the leg bone's connected to the foot bone..." and so on.

Can anyone offer a bit of help so that I don't have to go through the hassle of hauling the bike over to the LBS?
 

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What the LBS would do

Starting from scratch,first shift the chain into the granny gear and biggest cog in the back.Now what you do is adjust the (low) limit screw until the fr der bearly misses the chain,this is your lowest gear setting.From here you want to fing your barrel adjuster on the front shifter and screw it all the way in than out one full turn.Now you loosen the cable clamp bolt and pull the cable tight than tighten the bolt. (make sure the left shifter is in one)and then start shifting from there,it should go all the way up now.If it almost goes there than unscrew the barrel adjuster on the shifter until it does.
 

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sounds like a cable tension problem....

If you've unscrewed the H limit and it wont go to the big ring, try this:

Screw in the barrel adjuster on the shifter all the way in, to create as much slack as possible.

Loosen the cable clamp and use pliers to take out all of the slack. Retighten the cable.

Use the shifter's barrel adjuster to create the correct amount of tension in the cable. With the right amt. of tension, the chain should jump over the big ring. Tighten down the H limit screw to prevent this.

If none of this helps, it could be a chainline problem.. good luck
 

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Sofa King We Todd Did
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Discussion Starter #4
Cool. I'm printing out your responses and am going to use them as a guide when working on the bike.

Cheers!
 

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One more thing to check.

SpinWheelz said:
Quite simply, I'm having problems with my front derailleur, getting it to shift from the middle chainring to the largest one. These days I'll shift the lever, the derailleur with move, but the chain with stay on the middle chainring while rubbing away at the derailleur cage. Random acts can temporarily 'rectify' this problem and shift the chain over - stop pedalling and start again, shifting to a smaller cog in the rear, that sorta thing.

I've meddled with the H-limit screw a bit. I've unscrewed it quite a bit in hopes that this will bring the cage outwards a bit more when I'm upshifting so that it'll help pull the chain out to the largest chainring, but that hasn't helped too much. I've lubed the chain a couple of times now. I've even tried tugging at the derailleur cage. And I've tried reading up the repair help section at Park Tools. All to no avail.

A quite bit of background - I had nasty crash about a week ago that slightly bent the rear derailleur to the point that when I tried shifting to the largest rear cog, my chain would get dropped. In that time, I've bent the rear derailleur back and everything shifts quite cleanly now. Now the front is giving me problems. Could my front derailleur problems be caused by my rear derailleur? I ask because I know that almost nothing works independently on a bike and that "the hip bone's connected to the leg bone, the leg bone's connected to the foot bone..." and so on.

Can anyone offer a bit of help so that I don't have to go through the hassle of hauling the bike over to the LBS?
Since you said you had a nasty crash, have you checked the front derailleur alignment? When the outer cage is over the largest ring, it should be parallel with it and should be between 1-2 mm above it.

Duc
 
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