Rear Derailleur adjustment for newbies

[bentbike33]

@lordofthemark 168010 wrote:

I put the bike up on the rack, and yeah, I guess this time it did seem like the squeak was coming from the jockey wheels. I lubed them as best I could (I don’t yet have spray lube). They still squeak – it looks like the chain presses against the metal thing that holds the jockey wheel. I will get spray lube and try that, but I fear that will not solve it, and again, I am reluctant to mess with the jockey wheel or it’s holder. And I fear the rubbing, aside from being embarrassing, is doing damage to the chain.

How many miles are on the derailleur? Sounds like maybe one of the jockey wheels is shot if the chain is rubbing on the derailleur cage (which, by the way, will suffer far more damage from this condition than the chain).

[lordofthemark]

Well I have ordered spray lube from the evil folks in Seattle (not tim and bobco) .

But I have a different problem. Sunday before last I took my first ride with bar mitts. I always get a little confounded shifting under them till I am used to it, and made the mistake of taking the Custis Westbound, and shifting the crankset into the small gear. Which resulted in the chain getting caught in between the bike and the crankset, so that the bike was immobilized, not even walkable. Not wanting to carry it to a bike shop or a bus, I played with it awhile, and finally brute forced the chain out. Yay!. But after that I found it slipped badly in several gears on the cassette (its okay on the biggest gear, and the four smallest, but almost unrideable on the gears between, which I do like to use). I talked to LSG about this at the next CCCC, and he diagnosed the problem as a stiff chain link which would account for why the slippage was happening right after the chain incident. And he suggested that it would be consistent with the other gears working, if the geometry was such that the chain could fit more comfortably over them. He also gave me a way to check for a bad link.

However by the time I put the bike on a stand and checked, I had forgotten his suggested way to check. I ran the chain around and looked for a particular inflexible link, but didn’t find any. I also tried a method I found online, looking for ones that jumped over the jockey wheel when the chain is moved backward, and didn’t see any of that either.

Meanwhile I have been riding minus some gear options, which is unpleasant in a couple of ways. Before I take it into a shop, if anyone can either offer an alternative diagnosis, or a way to check for stiff links, I would be happy.

[hozn]

It sounds like the strategies you used are the same I would use (you can see a stiff link jump over the jockey wheels).

Is it possible you bent your derailleur hanger when you had this chain suck issue?

[bentbike33]

Given the chain-suck incident and its violent resolution, I would suspect one or more links may be bent, and with that comes the danger of breaking the chain as a plate comes off the pin. This would explain the chain skipping in the larger cogs, but not the largest cog, as the bent link catches on the shifting ramps on these cogs.

Probably time for a new chain.

[lordofthemark]

[ATTACH=CONFIG]15785[/ATTACH]

[ATTACH=CONFIG]15786[/ATTACH]

[ATTACH=CONFIG]15787[/ATTACH]

[lordofthemark]

Here are three pictures of the rear derailleur, from different angles. It does not appear out of place to me, but perhaps others have more insight.
[ATTACH=CONFIG]15788[/ATTACH]

[ATTACH=CONFIG]15789[/ATTACH]

[ATTACH=CONFIG]15790[/ATTACH]

I again looked at the chain. I saw nothing that looked to me like a bad link, no loose plates, and it moved smoothly over the jockey wheel. It did make slipping noises over the cassette gear, but I could not what physically was doing that.

I am thinking of just taking it in to a bike shop at this point. There is one a block from here, and I am sorely tempted.

[bentbike33]

@lordofthemark 168870 wrote:

Here are three pictures of the rear derailleur, from different angles. It does not appear out of place to me, but perhaps others have more insight.

[ATTACH=CONFIG]15785[/ATTACH]

[ATTACH=CONFIG]15786[/ATTACH]

[ATTACH=CONFIG]15787[/ATTACH]

I again looked at the chain. I saw nothing that looked to me like a bad link, no loose plates, and it moved smoothly over the jockey wheel. It did make slipping noises over the cassette gear, but I could not what physically was doing that.

I am thinking of just taking it in to a bike shop at this point. There is one a block from here, and I am sorely tempted.

When you say “slipping noises” do you mean it sounds like it is trying to shift unsuccessfully? Or does the chain pop up to a bigger cog then back down in short bursts? If that, you might just need a slight cable adjustment (probably tightening) by turning one of the barrel adjusters (at the shifter or derailleur) counter-clockwise (lefty-loosey).

[hozn]

@lordofthemark 168870 wrote:

Here are three pictures of the rear derailleur, from different angles.

Probably the most useful angle, when trying to diagnose shifting issue, is one taken from directly behind the derailleur at various points in the cassette; this should show the RD jockey wheel relative to the cogs and indicate if derailleur needs adjustment. Showing this position for a few different cogs (e.g. gears 2, 5, 9) should also hint at whether the hanger might be bent — though that might also be possible to tell from the angle of the RD cage.

[bentbike33]

One more thing to check is for a slightly frayed derailleur cable. One or two of the component wires in the cable can break and bunch up in the cable housing leading to all kinds of misbehavior in an indexed shifting system. Your pictures aren’t quite high-res enough to tell, but it does not look like there is any fraying near the derailleur anyway.

[Judd]

@lordofthemark 168870 wrote:

I am thinking of just taking it in to a bike shop at this point. There is one a block from here, and I am sorely tempted.

Looks like Karen gave you a lemon. I advise consulting legal counsel at this point. Or just taking it to a cool bike shop that will show you what was wrong and how they fixed it.

[lordofthemark]

@Judd 168878 wrote:

Looks like Karen gave you a lemon. I advise consulting legal counsel at this point. Or just taking it to a cool bike shop that will show you what was wrong and how they fixed it.

I take full responsibility for being a wimp on what some people consider to not even be hills (and thereby causing what was certainly an avoidable chain suck scenario)

[Steve O]

I’m 50/50 that all you need is an adjustment. A couple tweaks of the barrel adjuster; making sure the limit screws are set right; good to go.

Let me know if that’s all it turns out to be.

[huskerdont]

If you haven’t done it much, derailleur adjustment really is the kind of thing where it helps to watch an expert do it once, either in person or on a video. Once you have (and can remember which way to turn the barrel), that part is pretty easy, and if it doesn’t work, then you know you probably have something else going on.

[lordofthemark]

@huskerdont 168931 wrote:

If you haven’t done it much, derailleur adjustment really is the kind of thing where it helps to watch an expert do it once, either in person or on a video. Once you have (and can remember which way to turn the barrel), that part is pretty easy, and if it doesn’t work, then you know you probably have something else going on.

It is done. Took it to Conte’s Navy Yard, they adjusted the derailleur, and that fixed it. They did talk me through it, but wanted me on the other side of the counter while I watched, I probably could not do that myself without watching some videos. The shifting is now fine. They also spray lubed the jockey wheel (my spray lube from Amazon should arrive today along with some new lights, but oh well) and the squeak is gone too.

[Steve O]

@Steve O 168891 wrote:

I’m 50/50 that all you need is an adjustment. A couple tweaks of the barrel adjuster; making sure the limit screws are set right; good to go.

Let me know if that’s all it turns out to be.

[ATTACH=CONFIG]15801[/ATTACH]

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