Rear derailleur won't shift all gears - Shimano Dura Ace Di2 ST-7970 STI

Mark:

First of all, make sure that you are not over or under shifting. The chain has to be positioned exactly over the gear that you are trying to use. If you hear derailleur or chain noise The derailleur is not "in gear" and you have to adjust your shifter to eliminate noise. The derailleur must be adjusted so that the chain is parallel to the gear cluster in each gear. If the chain is twisted at all, it will skip gears. Check your rear derailleur to ensure it is pointing the chain directly at the front gear cluster. Check the front derailleur to see that it is pointing the chain directly at the rear derailleur. While you are at it... clean the derailleurs with alcohol and lube them with a light weight oil. Check the derailleur stops (small screws next to the cable clamp on the derailleur). Have the bikes rear tire off of the ground and pedal the bike with one hand while shifting with the other hand and you can see what the derailleur is doing. adjust the stops so that you can not shift the chain off of the gear cluster in high or low gear. You may have to adjust the cable length at the derailleur cable clamp, and at the adjusters on the shifter to get the exact adjustment that you want. It will take some time to properly adjust your derailleurs, but it is worth it when you can ride without your derailleurs acting up.

Try flushing out the shifter(s) with WD-40, use plenty. The next step will be replacing the shift cables and cable housings.

• Take the bicycle in an area free of cars and obstacles, such as an open parking lot. Concentration is required when learning to use Ultegra shifters or any other type of bicycle shifter.
  
• 2 Mount the bicycle and rest both hands on the proper Ultegra hand control. The left-hand control operates the front derailleur. The right-hand control operates the rear derailleur.
  
• 3 Start pedaling, smoothly and evenly. While pedaling is crucial to propelling the bicycle forward, it is also necessary when shifting the derailleur. Pedaling forces the chain to rotate. The chain must rotate before it can transfer to another gear.
  
• 4 Push the outside right Shimano Ultegra lever in toward the bicycle. The rear derailleur will shift the chain to a smaller rear gear.
  
• 5 Push the inside right Shimano Ultegra lever in toward the bicycle. The rear derailleur will shift the chain to a larger rear gear.
  

Rear Ultegra Derailleur Control

• 1 Push the outside left Shimano Ultegra lever in toward the bicycle. The front derailleur will shift the chain to larger front gear.
  
• 2 Push the inside left Shimano Ultegra lever in toward the bicycle. The front derailleur will shift the chain to a smaller front gear.
  
• 3 Use the front and rear Ultregra hand controls interchangeably. For small changes in gearing, using the rear control. For larger changes, choose the front control. A smaller gear causes the bicycle to travel a shorter distance per pedal stroke but also requires less energy to use. A larger gear requires greater effort but in turn causes the bicycle to travel farther per pedal stroke.
  

the derailleur cable is too loose. Shift the shifter into the smallest cog, make sure the chain is on the smallest cog. The derailleur cable will most likely be very slack now. At the rear derailleur, there will be a nut or a allen bolt pinching the cable to the derailleur. loosen this, pull the cable finger tight, tighten the nut or bolt again and then try shifting again. You can dial it in using the barrel adjuster on the derailleur or the shifter.

Hello,

Have a helper lift the rear wheel of the bicycle slightly off the ground.

2
Kneel beside the bike and turn the pedals slowly by hand. Using the shift lever, adjust the front derailleur so that it rests at about the midpoint of its movement range.

3
If the initial problem is that the chain won't shift onto the largest rear gear, locate the two small side-by-side adjustment screws on the rear derailleur. Turn the left (or upper) adjustment screw counterclockwise a quarter turn with a small Phillips screwdriver. If the initial problem is that the chain won't shift onto the smallest rear gear, skip to step 6.

4
Continue turning the pedals and shift through all the rear gears. If the chain will still not go onto the largest rear gear, shift the chain back down to the smallest rear gear. Turn the right (or lower) adjustment screw clockwise as far as possible before the chain begins to click or rattle.

5
Shift through the gears again to test. If necessary, turn the left (or upper) screw counterclockwise another quarter turn.

6
If the initial problem is that the chain won't shift onto the smallest rear gear, begin by turning the right (or lower) adjustment screw counterclockwise a quarter turn. Shift through the gears to test.

7
If the chain still won't go onto the smallest rear gear, shift the chain to the largest rear gear. Turn the left (or upper) adjustment screw clockwise as far as possible before the chain begins to click or rattle. Shift through all the gears to test.

8
Follow steps 1 through 7 for the front derailleur, which operates on exactly the same mechanism as the rear derailleur (you still lift the rear wheel in step 1). There are two side-by-side adjusting screws that control alignment.
If otherwise,
Tighten the high gear screw, the one that hits a cam when you shift to the smallest sprocket, until you can no longer shift into high gear. Put the shifter in high gear position and while turning the pedals, unscrew the high gear screw until the system engages high gear again. Shift between high gear and the second smallest several times, backing the screw out a little more, just until the derailleur shifts smoothly.

2. Tighten the low gear screw until you no longer get first gear. Repeat the process for this low gear limit - back the screw out just until the bike shifts smoothly from the second largest to the largest sprocket.

3. If you cannot engage high or low gear, or if the above technique does not work for high or low gear, the cable may be improperly adjusted.
Shift into high gear and push the shifter all the way to the end of its travel. Loosen the cable inner wire anchor bolt. That's the bolt with a hole through which the derailleur control wire is clamped. Pull the slack out of the wire, and retighten the anchor bolt.

If your bike has index shifting, you'll find an adjusting barrel either at the derailleur or the shifter. The adjusting barrel is a hollow screw at which the cable outer housing stops, but which the inner wire continues through. Fine adjust the cable tension by turning the adjusting barrel until the clicks on the shifter correspond with proper shifting at the derailleur.

If your bicycle does not engage high gear, or is slow to engage high gear, even though properly adjusted, the cable is probably the culprit. Replace the sticky or rusted cable, and the problem will usually go away.

If you have done everything right, but the bicycle does not shift reliably, the most common reason is that the chain and freewheel are too worn to work properly. If you replace one, you must replace both. A new chain on an old freewheel or visa versa usually skips, and the new part wears out very quickly.

Another possibility is a bent derailleur. The guide pulleys, those little wheels that take up the chain slack, must pivot on the same plane as the freewheel sprockets. Derailleurs become bent when the bike falls over on the right-hand side. Whenever you set a bicycle down, or put it in a car, set it on its left side to protect the derailleur. You can sometimes straighten out a bent derailleur by simply bending it back and readjusting the limit screws.


Hoping this will help to solve the problem, do take care....

Simple web searches will answer many questions like yours immediately.

http://www.parktool.com/blog/repair-help/front-derailleur-adjustments

Chains are intended to move in multiple dimensions while driving the bike or shifting among the gears. YOUR calibrated eyeball can see it while we can't. The Web has lots of advice and resources to well-crafted queries like "front derailleur won't shift" or "rear derailluer won't shift".

"how to (whatever)...." works for many things, too.

Great resource ...

http://www.parktool.com/blog/repair-help

Wash, degrease and scrub the chain and derailleurs with a good degreaser (like Simple Green). Dry the chain and relubricate it with an appropriate bike chain lubricant (not oil or WD-40). Shift the derailleurs to the smallest chain ring and cog on the cassette (low front gear, high rear gear) and then loosen the cable at the derailleurs, pull the cables taut and reattach them. If the derailleurs still need adjustment, here is a procedure for it:
Flip the bike over (so you can pedal the bike manually while you shift) and shift the front to the middle chain ring. Shift the rear to the highest gear (small cog). Release the cable from the pinch bolt on the derailleur. Adjust the screw marked "H" on the derailleur until the jockey wheel on the derailleur is aligned perfectly over the small cassette cog. Set the cable adjuster on the derailleur to the middle of its range (find this by screwing it all the way in and then count how many revolutions it makes until it screws out completely. Screw it back in one half of the total revolutions). Reattach the cable and shift to the lowest gear (the biggest cog). Over-shift and hold on the shifter, then adjust the "L" screw on the derailleur until the jockey wheel sits just past the last cog. You have to hold the shifter to do this. Now shift into the middle gear (or one of the two middle gears if the bike has an even number of gears) and adjust the derailleur using the barrel adjuster you previously set to the middle of its range. Adjust it so that the derailleur is sitting perfectly over the appropriate gear. Shift up and down the cassette while pedaling and in every gear, reverse pedal (freewheel) to make sure the chain does not hop. Adjust as necessary until all gears are smooth.
Now the front:
Set the rear derailleur to the lowest gear (big cog) and the front to the lowest gear (small chain ring). Disconnect the derailleur cable. Screw in the adjuster for the cable tension all the way (this adjuster is on the shifter of a mountain bike or the down tube of a road bike). Pedal to make sure the chain is not rubbing on the derailleur cage. If it is, adjust the "L" setting on the derailleur until the chain moves by without touching the cage. Now pull taut and reattch the cable and shift the front to the big ring while pedaling. If it does not shift up well or completely, hold the shifter past its normal shift and adjust the "H" screw so that the derailleur allows the shift. Shift into the highest cassette gear and keep pedaling. The chain should not be touching the front derailleur's cage when you pedal. Adjust with the barrel adjuster until the chain moves freely without touching the derailleur cage.
That should be it, unless there is another mechanical problem causing the missed shifts, like a bent derailleur hanger or damaged teeth on the cassette cogs or a bad derailleur. If it is still problematic, come back for further information.

i hope this helps
-matthew

Oh, it is too bad you are in the Bronx. i'd have that fixed right quick. There are probably a pair of culprits at work here. One, your derailleurs no doubt need adjustment. Two, your rear derailleur hanger may be bent. These two can both cause the problem. Start with the rear hanger, because that will be easier to see.
Flip the bike onto the bars and saddle and take a look at your rear derailleur. Is it going straight up and down and is it aiming straight with your frame? If it isn't, you have found your problem. The hanger needs to be straightened. This can be done without any tools if you have a good eye. Hold the derailleur by the body and bend it to make the alignment good with the cassette. If this is NOT the problem (but i really think it is) then here is a walk-through on adjusting your derailleurs and hopefully this will solve it.
Here is how to adjust the rear (first):
-Set your front gear to its middle position.
-Shift the rear into the highest gear.
-Disconnect the derailleur cable.
-Screw the barrel adjuster on the shifter (or down tube if it is a road bike) to fully turned in clockwise.
Screw the barrel adjuster on the rear derailleur to its halfway point.
-On the back of the rear derailleur you will see two screws. One will be marked "H" and the other "L". These mean high and low. Adjust high to get your jockey wheel on your derailleur perfectly centered over the smallest cog on the cassette. Manually shift by pushing the derailleur (while cranking the pedals) to the largest cog (1st gear) and set this stop on the derailleur "L" where the jockey wheel is over the cog, but past it where it would be touching the outside of the cog if they were side-by-side.
-Pull the derailleur cable taut and re-tighten it.
Shift the rear to the middle gear and adjust the derailleur using the barrel adjuster to center the jockey wheel directly over the cog it should be.
-Now shift up and down the cassette, cranking as you go and in every gear, back-pedal to make sure there is no problem with the gears hopping. If they do, adjust as necessary with the barrel adjuster.
Here are some tips for the front:
-Shift into low gear on the front and rear derailleurs. Make sure the chain is not rubbing on the front derailleur. If it is, adjust the screw marked "L" until the chain just clears the derailleur but does not touch it.
-Pull the derailleur cable taut and re-tighten it.
-Now shift the front into the middle gear and while it is still in the low gear in the back, crank to make sure the chain is not rubbing on the front derailleur. If it does, adjust the tension of the cable with its barrel adjuster.
-Shift the front into high gear and shift the rear to the highest gear, cranking as you shift. If the chain is not rubbing, you are all set.

Try this:
Set your shifter to the highest gear while turning the crank. If you have to, manually set the derailleur to the highest gear.
Release the derailleur cable by loosening its screw.
Pull the cable taut and re-tighten the screw that clamps the derailleur cable.
You should be all set.
The cable stretches over time. This can be avoided by "pre-stretching" new cables. To do this, simply shift into first gear and pull the derailleur cable away from the frame (where you are able to do so) fairly hard, several times. Then you just release and re-tighten the cable like mentioned in the steps above.
Happy riding!
matt
[email protected]

Front or rear? What is it doing?
Flip the bike over onto the handlebars and saddle and let us fix it.
Here is how to adjust the rear (first):
-Set your front gear to its middle position.
-Shift the rear into the highest gear.
-Disconnect the derailleur cable.
-Screw the barrel adjuster on the shifter (or down tube if it is a road bike) to fully turned in clockwise.
Screw the barrel adjuster on the rear derailleur to its halfway point.
-On the back of the rear derailleur you will see two screws. One will be marked "H" and the other "L". These mean high and low. Adjust high to get your jockey wheel on your derailleur perfectly centered over the smallest cog on the cassette. Manually shift by pushing the derailleur (while cranking the pedals) to the largest cog (1st gear) and set this stop on the derailleur "L" where the jockey wheel is over the cog, but past it where it would be touching the outside of the cog if they were side-by-side.
-Pull the derailleur cable taut and re-tighten it.
Shift the rear to the middle gear and adjust the derailleur using the barrel adjuster to center the jockey wheel directly over the cog it should be.
-Now shift up and down the cassette, cranking as you go and in every gear, back-pedal to make sure there is no problem with the gears hopping. If they do, adjust as necessary with the barrel adjuster.
Here are some tips for the front:
-Shift into low gear on the front and rear derailleurs. Make sure the chain is not rubbing on the front derailleur. If it is, adjust the screw marked "L" until the chain just clears the derailleur but does not touch it.
-Pull the derailleur cable taut and re-tighten it.
-Now shift the front into the middle gear and while it is still in the low gear in the back, crank to make sure the chain is not rubbing on the front derailleur. If it does, adjust the tension of the cable with its barrel adjuster.
-Shift the front into high gear and shift the rear to the highest gear, cranking as you shift. If the chain is not rubbing, you are all set.