Brand new bike gears won't engage. The gear shift is on 6 and the chain is on the smallest cranks.

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....

I would lube everything and check the derailleur adjustments and cable tension. Some Campy chains are 'notchy/clunky' all the time. It's just the way they are. If the bike is low mileage most likely nothing major is wrong. Check the derailleur hanger too just in case you dropped the bike and bent it or something. The shifter 'G' springs will wear out before the derailleur. When the springs are worn, the shifts will be imprecise and will jump from gear to gear without shifting. One thing with Campy stuff...it DOES take awhile to break in. Unless the shifting is horribly off, I wouldn't worry about it - just ride it more - and see what happens. Mirage is a good product, I think inline with Shimano 105 stuff.

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

Bicycles have two sets of gears (front and back). The 6 position control slides the chain between the 6 sprockets (cogs) on the back. The 3 gears are for the front set of cogs. Between the two sets of sprockets, you get 18 (theoretical) different rates of chain movement per turn of the pedals. In fact some of the settings overlap. (However some of these should not be used. Do not use the settings that pull the chain to the furthest inside of one derailleur and the furthest outside of the other. This diagonal between the biggest and biggest sprockets (or smallest to smallest) puts extra strain on the chain.) The back derailleur is in the lowest gear when on the biggest sprocker. The front low gear is on the smallest cog. The highest gear possible is on the smallest rear cog and the largest front cog.

By planning the shifts in gears, you can maintain the same speed and cadence (rate of pedalling) on different terrains. (For going up a hill, use a lower gear than on flat terrain. However don't go to low or the bike may not balance well.) To shift through a large range of gears, you must be pedalling and then move the rear derailleur control followed by the front derailleur then the back again. (For faster shifts to a low speed, you can shift the front derailleur first but that can stress the system.)

For a guide to using the gears: http://www.southcoastbikes.co.uk/articles.asp?article=Gears .

I hope this helps.

Cindy Wells

Don't start messing with the derailleur yet! Make sure your shifting trouble isn't due to something else, such as a warped, dirty, or stretched chain, gummed-up pulleys, crud in the cable housing, trapped cable, or a bent derailleur hanger
Clean the chain and the rear derailleur pulleys. Pull the chain away from each pulley, and turn the pulley to make sure it can move freely. A pulley that offers resistance to turning must be replaced.
Now check the cable to be sure it slides freely. Mud and grit within the cable housing, or on a cable-guide, can keep the derailleur from moving a "full gear" during downshifts. If the cable doesn't slide freely in the housing, you may be able to clean or lube it to restore smooth shifting.
Let the high-gear limit screw. In your highest gear on the shifter, and with the chain on the smallest cog, position the derailleur so the upper pulley exactly matches the teeth of the small cog. Run the chain a bit with the front derailleur in the large ring, adjusting the limit screw until the pulley and the cog seem to match perfectly.

Setting the high-gear (small cog) limiting screw.

Once you're sure the derailleur matches the cog, move it just a whisker (1/8 to 1/4 turn) towards the other cogs. (You may need to readjust a bit if you get chain-skip.)

Closeup of setting the limiting screw.

Now adjust the low-gear limit screw. Shift into the lowest gear (largest cog). If it won't go, loosen the limit screw. With the chain on the largest cog (and the front derailleur in the small chainring), adjust the derailleur so the upper pulley exactly matches the teeth of the large cog.Once it's perfect, turn the limit screw so it moves the derailleur a tiny amount towards the other cogs (1/8 to 1/4 turn usually works).

Setting the low-gear (largest cog) limiting screw.

Now shift to the highest gear (smallest cog). Push the shift lever to downshift one gear (go from the smallest cog to the next-smallest). If it doesn't shift, tighten the cable with the barrel adjuster, 1/2 turn counter-clockwise. Backshift and try again. Continue tightening until it shifts. If it overshifts, going from the smallest cog to the third-smallest, loosen the cable by turning 1/2 turn clockwise. Backshift and repeat until it shifts exactly from the small to the next-smallest cog.

Fine adjustment of tension in the derailleur cable.

Now go to the second-smallest ring. Tighten or loosen the cable slightly, until the outer side plates of the chain are just clearing the third-smallest cog. Shift up and down, fine-tuning until you're satisfied.

Checking the position of the chain on the cogs.

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.

There should be one or two limiting screws for the front derailleur that you can use to adjust how far out/in the derailleur moves to shift the chain over. You can ask a friend to lift the back end of the bike off the ground while you do the adjusting of these screws and then try shifting the gear while moving the peddles with your other hand.

Assuming that the limit screws are set correctly on the rear derailleur, which they probably are if you haven't fooled with it, and your cables are okay, here is what you do. If you don't have a bike workstand, then get someone to hold the bike up or hang it off the ground with a rope. Turn the cranks and shift to the highest gear (the smallest and outer rear cog). If the chain does not go out to it, then screw the barrel adjustment in the rear derailleur (where the cable goes into it) in until it goes to the outside cog. Beginning with the chain on the outside cog shift to the next lowest gear (keep turning the crank at all times) If the chain does not go to the next smallest cog, then turn the barrel adjustment out until it does. Now try shifting it through all the gears to the inside cog and tweak the adjustment with the barrel adjustment. Also, you might have to take out slack in the inner wire if it has "stretched" out, by loosening the cable bolt on the rear derailleur, pulling the cable tight, then retightening before any of this will work.

Starting with someone holding the bike with the front of the bike to your right proceed as follows. Shift the rear derailleur down so that it lines up with the smallest cog on the rear. Shift the front derailleur to the smallest cog on the front. This will give you the least resistance to thread the chain. Starting at the rear lay the chain over the rear cog teeth and holding the arm of the derailleur down so that the idler gears are one above the other thread the left end of the chain to the right side of the top idler gear and down through the cage. proceed with the end of the chain to the left side the the bottom idler gear and down . The left end of the chain you just threaded will now meet the right end of the chain which you are about to thread. Don't let the left end slip back the way you came. Take the right end of the chain and thread it through the cage of the front derailleur and over the smallest gear on the front proceeding to your right. It should be sitting in the teeth.Pull the right end of the chain down and arouind to meet the left end of the chain. Since you are asking how to thread the chain I am assuming that it is apart in one long length and not in a continuous loop. Use a twist tie to hold the two ends of the chain together for now. Shift the front derailleur to the largest outside gear taking care to lift the chain off the teeth of the small gear and place them on the large gear as you are shifting. Shift the rear derailleur to the largest inside gear(cog) on the back wheel taking care to move the chain again as you shift. The chain should be in a continuous loop with no twists in it that goes as I described through both derailleur cages and over the largest gear on the back and the largest gear on the front. Now the tricky part. You may need someone to help. You have to pull the chain with your left hand to move the rear derailleur cage all the way forwardand with the twist tie removed bring the right end of the chain all the way back to the rear along the left end of the chain to measure how long it would be joined up in that position. Note where the chain would meet if tight. You will have excess chain on one end. From where the ends meet give yourself two links on the excess end of the chain and where the ends will join now is the correct length. You will need a chain (break) tool to force the pin out on the excess end of the chain to remove the excess length.You have two choices for joing the chain. You can buy a pin that you can join the two ends with and when it is forced through to the mark on it with the tool you then snap the end off with a pair of pliers or you can buy a joiner link that comes in two halves that fit through the holes on opposite sides of the chain and then snap together. The forward action of pedalling will make the final snap to hold the link on. If you decide on the latter method you will notice that you will have to remove another pin from the length to get the side plates off the chain and expose both holes. This is a complicated explanation and if you haven't done this before and you don't have a chain tool it is far easier to get a bicycle shop to install a new chain as the actual chain has to be a direct match in manufacturing to properly fit your bike. If you decide to do this yourself, take the old chain in and get a new one. Make sure it hasn't been shortened as the old chain has probably been stretched and the proper method of measuring the new one is by using the bike itself not just laying the new one and the old one side by side. Good Luckand hope this helps.