Adjusting derailleur after cable change

[doodlebug]

I had to replace the rear derailleur on my "old" Shimano Exage SIS equipped bike today and for some reason I cannot figure out how to adjust the slack out of the cable.

Can someone please give me a short tutorial on how to do this? On what cog should the chain be and what chain ring, or does it make any difference? Also, where should the shifter be? Every time I pull the slack out of the cable and tighten down the pinch bolt, I will still have way too much slack.

BTW, the rear derailleur on this bike automatically wants to go to the large cog, not the low one as some of them do.

Any help would be very much appreciated.

[xerxes]

First wind any barrel adjusters all the way in, then back out 1 turn.

Now put the shift lever in the position it would be for the lowest gear (largest cog) at the rear, pull the cable tight and tighten the clamp nut.

How is it now?

If that, has worked, adjust the barrel adjuster so that the shift indexes correctly. There's a video about that in the repair guide if you're not sure how to do that.

If that doesn't solve the problem, what make and model levers and rear mech do you have exactly?

[doodlebug]

The bike has all Shimano EXAGE components on it. The shifters are Shimano Index.
I turned both barrels all the way in and then back out one turn. I then place the chain on the large cog in the rear and the small chain ring. The shifter was in the low position. I then tightened the cable.
I then turned the crank and tried to index through the gears and nothing would happen. The shifter clicked normally, but the rear derailleur would not move at all. And then when I returned the rear shifter to the low position, again I got a bunch of slack in the cable. It does that every time.
I'm obviously doing something wrong, but I can't figure out what.

[xerxes]

I'm not entirely sure what you're doing wrong.

Have you watched the video http://bikeride.com/inner-shift-cable/

You are tightening the pinch bolt aren't you?

[doodlebug]

Sorry I haven't responded. I got so frustrated that I just quit trying to fix it. I suppose I could just take it to a shop, but I've always tried to do things myself.

Anyway, back at it again. I've gone over the video several times and have done exactly as they describe, but the problem still exist. I placed the chain on the large rear cog and took the slack out of the cable and tightened the pinch bolt. I then tried to shift through the gears, but the cable is so tight, I can't get the shifter to move all the way forward. The shifter is suppose to be all the way to the rear when making the initial adjustment, correct? When I shift back down, I keep getting a lot of slack in the cable. I'm beginning to think I've got a bad rear derailleur.

I hope I'm making sense here. Maybe somebody can help. Thanks.

[bobtravers]

Put the shifter so the chain is on the smallest cog... Then slack the bolt retaining the cable, and stretch it so it's hand-tight... Then screw back the bolt.

Shift one cog up, if the chain is not going up while rotating the crank, adjust the barrel counter clockwise to put some tension on the cable... When you see the chain going up, the cable should be at a good tension, and all others shifts should be almost perfect...

[DaveM]

I'm confused by the problem you're having. But one suggestion is to try starting out with the shifter at the other end of it's range. Maybe you've got the high/lo reversed.

But if you tighten the cable at one point, shift through the range and go back to exactly where you started, and THEN have slack. It sounds like the cable is slipping through the anchor bolt or you don't have the housing seated properly everywhere.

[doodlebug]

Thanks for all the help. I did put the chain on the small cog and put the shifter in the high position (all the way forward). I pulled the slack out of the cable and made sure the cinch bolt was down tight. Again, when I shifted down, the derailleur would not move and when I shifted up, a lot of slack would get in the cable.

I tried doing this with the shifter at the other end of the range and the same thing happened, no shifting and slack when I moved the shifter in the other direction.

It seems like the derailleur naturally wants to go to the large cog. I'm wondering if I should try it with the chain on the large cog?

Just another thought, there is a "lever" type thing that the cinch bolt is mounted to. This thing moves back and forth with the movement of the cable. I'm wondering if this might be defective or something.

I guess its time to visit the shop and let a professional take a look at it. I know when I'm whooped. Thanks for all your help.

[cyclerUK]

From your description it sounds like you have what is known as "low normal" derailleur.
i.e. The dérailleur, when the cable is slack, moves to the large sprocket.
I am wondering if this matches your Exage changer?

If it does, then to set it up.
Pull on the cable and move the changer to its extremity to slacken the cable.
Now let the dérailleur move to the large sprocket.
Turn the pedals so that the chain turns smoothly on the large sprocket.
You may have to adjust the Lo screw to get the setting.
(The wheel will have to be off the ground or turn the bike over and rest it on the saddle / bars.)
Now attach or adjust the cable so there is hardly any slack in the cable.
Then move the shifter to the next position and the chain should move to next sprocket.
If it does then fine. If it doesn't, then tighten the cable cable until it does.
Do this through the range of gears and fine tune the cable to suit.
If you can't get good shifting then maybe the dérailleur doesn't match.

Check out this video but yours will just be opposite with regard to the chain position.
** Start off on the big sprocket**

[doodlebug]

I've had this bike since new, way back in the mid 80's and nothing has been changed on it so I know the derailleur matches.
I think I've already tried the procedure you suggest, but I'll try again just to make sure.
I've got two other bikes and I've changed the brake and derailleur cables on all of them and I've never run into a situation like this. I keep hoping it's something simple that I'm overlooking. Thanks for your help.

[cyclerUK]

With a "low normal" derailleur, as you pull on the cable the derailleur moves the chain from the large to small sprocket.
Initially pull the cable by hand to make sure the derailluer will move across the sprockets.
It shouldn't matter which chainring the chain is on.
As you've done your other bikes then this one should not be a real problem. ? ?

[doodlebug]

I pulled the derailleur from the bike today and was looking it over. I discovered that the spring that controls the lateral movement of the derailleur is broken. It doesn't look as though that can be replaced so I'm looking for a new derailleur now.

The one on the bike is the M450, six speed (the old biopace stuff). These are almost impossible to find now although I did see some 300's and a couple of 500's on ebay. I was wondering which new derailleurs would work with my current shifters. Most everything today is 8, 9, 10 speed stuff, so it may be asking a lot to find something that will work with a six speed setup. Again, your help is appreciated.

[cyclerUK]

Glad you have found the cause of the problem.
Any current 6,7,8 speed Shimano dérailleur will match.
They all work on the same principle and cable pull.
The difference is in the changer.
(You could even use a 9 speed but I don't know if you will have problems with chain width.)

Assuming you have a triple chainset then you need a long cage version.
If your largest rear sprocket is 28 teeth or above then go for an MTB dérailleur.
If 27T or below then you can use a "road" dérailleur but the MTB one will still be good