Worn out Rear Derailer

[Woofie]

I have been told that my RD is on its way out because there is a bit of play on it.

My question is.

What causes this play?

Is it just the movement over time that wears down the linking points until there is a bit of play?

Is it not possible to service it at all? ie. Take it appart and put in some super heavy locktight or grease or something to help stiffen up the moving parts?

Lately I have been struggling quite a bit with my gears so as I ride I adjust the fine tune screw on the downtube as I ride.

I get it all smooth and changing nicely, sounds smooth, no skipping.

And then like the very next day I might have problems with a few gears sounding noisy again.

Do you think that this is the RD that is just too worn and now the adjustments I am doing are not working as they should because of that?

My cables arent that old so I dont think that it would be those.

And I dont think it would be my shifters either.

I am led to believe that shifters dont really "break" gradually, they will just  stop working when they are "worn out". Is that true?

 

Thanks guys!

 

 

 

[techguy]

It is possible that its worn out, they generally have steel pivot pins that the aluminium parts move on and over time the pivots (and springs) do wear out. Also keep in mind that th RD is close to the ground and will always get dust on it thereby speeding up the process...

[Duathlete007]

I also had the same situation. I have a previous shimano XT series rear derailer. I did a close inspection on the derailer and the hanger which hold the derailer on the frame. What i found is that the hanger itself was loose. So i tried fastening the ellen bolts but saw that the one ellen bolt was stripped. I called a few shops and bought me a new rear derailer hanger. From then onwards I had no problems. It is very important not to adjust your gears frequently. Make sure you have the knowledge to adjust it correctly! Maybe some time you have to let a technician set your gears for you. Hope you get a sollution for your issue!

[Woofie]

Thanks.

I get my gears adjusted so often at bike shops.

90% of the time though lately when I start riding I am not happy with the way it is preforming. So I do some minor tweaking with the barrel on the down tube and then it starts working way better.

 

Is there any difference between adusting gears on a bike stand and adjusting them on the road?

What I am trying to ask is does maybe the torque of you cycling or the parts working under stress make your shifting any different compared to when you are on the road? (I am not talking about shifting under heavy load either where you often have issues)

 

?

 

 

 

[techguy]

There can be a very slight differnce in loads between the road and the stand, but its very rare that the difference is that big to cause a huge hiccup...

[Woofie]

Ok, so basically

 

If I hang my bike up and am able to shift through the gears properly and then find a different response on the road then it is probably the RD?

 

 

 

[Johan Bornman]

Firstly, it is VERY unlikely that your derailer is worn out. Even new derailers have play in them, especially SRAM ones, with the main pivot being the big culprit. For it to wear those pivots it has to do millions of shifts. Look elsewhere for problems.

 

Then, pedal force should have no effect whatsoever on RD settings, although pedal force flexes the frame and affectes the FD - it rubs on alternate sides depending on which blade you are and which gear at the back.

 

Pedal force will however expose a worn cassette if you fit a new chain. This has nothing to do with gear settings.

 

Set your gears in the stand and be done with it. Road trimming is for people who can't set gears in the first place.

 

 

[Speed Devil]

If I was you I would first have a look at the gear cables and housings. You could maybe just have a sticky cable. First replace your cables and housings...it's way cheaper than a derailleur.

[Woofie]

Thanks for the input guys. I really appreciate it.

 

Maybe it is time to change the cables, however they dont feel sticky and they are only a few months old.

How long do cables normally last for on the road? (if I do, lets say maybe 8 hours a week)

My chain is only a couple of hundred old (maybe 300) and my cassette is about a month old as well.

 

JB, how do YOU set a RD?

Is there like a golden rule on the order of what to do when?

ie. Do you first put the rear trimmer into the middle and then attach the cable and adjust the tension so it is almost right. Then adjust the rear trimmer. Do you ever touch the front trimmer?

 

The way that I have been doing it, is I hang my bike up and I turn the rear trimmer all the way until it wants to start hopping. Then I turn it the other way until it wants to jump the other way and I count the turns as I am going through. Then I think that surely half the amount of turns back should be in the middle and it will work well there.

That seems to work ok for me, I then shift through the gears and do minor adjusting until it all sounds as quiet as it can be.

That normally works quite well, but then sometimes I hit the road and need to start playing with the trimmer again.

 

ACTUALLY it just dawned on me.......... I know what the answer is.

God is obviously trying to tell me that I need the electric DA.

I would never spend that much money.

 

 

[Johan Bornman]

How do I set an RD?

Like you say, there are a million different ways but here's my recipe for a low normal. Stand on your head and do it the other way around for high normal.

 

1) Remove the chain.

2) Loosen the cables from anchor bolt on the RD.

3) Screw the barrel adjuster all the way in.

4) Set the Limit screws.

5) Put the shifter in the most relaxed position i.e. shift to the high gear.

6) Replace the chain

7) Re-anchor the cable to the RD but put VERY LITTLE tension in the cable. For a SRAM system you actually have to feed the cable back 3mm or so so that there is ZERO tension in that cable.

8) With your right hand, pedal the bike and get up to a brisk pace. The rear sprocket should make the minimum noise now sice the limit screw is perfect.

9)Keep the pace on the pedal and shift up one gear. If the chain now jumps, you had too much tension in the cable to start off with. Stop and redo the cable so that there is less tension.

10) Start with the lowest gear again, pedal briskly with your right hand.

11) Shift one gear up. The chain should now not be on the second-last sprocket but stay on the smallest one.

12) With your left hand start turning the barrel adjuster out (whilst pedalling briskly) until the chain jumps into the next gear. Fine tune it there until it is quiet.

13) Test that the bike shifts into every gear up and down.

 

Job done.  4 minutes flat.

 

 

 

 

[Woofie]

Cool.

Your way is easier than mine.

 

Thanks guys.