Gustavoang

Hello, everybody.

I suspect that I've twisted my chain: It's rubbing the next sprocket, and as a consequence, it slips sometimes. At first, I thought it'd be the limit screws in the rear or front derailleurs, but I've ruled them out. Also, the chain isn't stretched and has the right length.

Here's a video from the front of the sprocket cassette and the back of the front derailleur: https://tinyurl.com/p8bwstj . And here's a video from the back of the rear wheel: https://tinyurl.com/qa27trj

I replaced the chain and the sprocket cassette 3 months ago, and I'm sure that I didn't have this problem back then. I then replaced the rear derailleur a few weeks later, and then the front derailleur a month ago. I noticed the noise days after replacing the front derailleur, but it might've been there before, I'm not sure. I've had to split the chain twice since I fitted it, and I think this is what caused the chain (or some of its plates) to twist/bend. However, I've only been able to spot one stiff link, which I fixed. This is what makes me hesitant about my hypothesis that it might be the chain -- I fear that I may replace it, and then find that it wasn't actually the chain.

I've spent a good chunk of time on the web, tried many things, but still no luck. Do you people have any suggestions?

And also, how much of a problem do you think this is? I'll be starting a week-long tour in Portugal next week, so I'd rather mitigate risks unless this really isn't much of an issue.

Thanks in advance!

redlude97

your RD clearly looks like it isn't aligned with your small cog which is why it is hitting the next one. That is either a limit or cable tension issue. In the smallest cog there should be no tension in the cable at all. Is this the case?

cny-bikeman

I could not get the videos to work, and even if I could have they looked a bit shaky. There's no substitute for being there, especially with drivetrain problms. If by "I replaced the chain..." you mean that you personally did the work there are multiple errors that could lead to the problem you are having, and there could be other problems of which you are not aware. So there's no way to tell online how much of "an issue" it is. I would strongly suggest you have a shop correct whatever deficiencies there are - it's better than being broken down in Portugal.

Gustavoang

Thanks, guys!

I checked the tension and the limit screws again, as per redlude97's suggestion, and it's now working properly. I then got a second opinion from a LBS and they thought it was fine.

redlude97

That may or not be true, but as you can see above, what I suggested fixed the problem. Small/small usually causes rubbing on the chainring, not the cassette. The chainline shouldn't be any worse than small/small on a triple drivetrain. When you set up the RD is correctly aligned over the small cog, then it'll hold the chain over the sprocket at the top as well to prevent rubbing on the adjacent sprocket.

oldbobcat

I should have read the whole thread. And I see how adjusting the derailleur keeps the chain centered over the cog. Thanks.