Derailleur problems

[Kookas]

I'm finding shifting is really dodgy, even after being properly indexed by the guys at Decathlon.

My LBS says the rear mech is worn, and it does seem like it's worn a bit. But Decathlon said it wasn't.

It's hardly done 1800 miles in total, but my shifting habits are a bit sketchy and the like, as are my maintenance habits.

Do you think buying a new rear mech could fix my shifting problems? It's actually unsafe to ride ATM because I'd be accelerating and then it will snap to the wrong gear.

Of course, chain jumping and poor shifting could be a worn cassette/chain, but the derailleur has unusual side-to-side movement that does seem to indicate wear.

It's been 700 miles since I last replaced the middle ring, chain and cassette, too. I don't know who to believe.

 

[Koga]

It is hard to say without seeing the unit, however I would check the jockey wheels for wear / play. Probably not relevant, but did you replace the cassette like for like (ie the same amount of sprockets?), if not indexing can be out.

 

[Globalti]

Don't believe any of them; derailleurs don't wear out that fast. However if you haven't replaced the cable in the last six months the shifting will be all to hell and you'll think you need a new derailleur.

You admit your maintenance is sketchy so change it and you'll be staggered at the difference in performance. Check the main mounting bolt is done up tight too.

 

[cyberknight]

Does it need a new inner cable?
If you get enough gunk in the cable lining it can cause the cable to not move properly even with new chain etc.

 

[Kookas]

I've replaced the inner not more than 200 miles ago, but being full of gunk could well be the case. How could I clear it of gunk?

And yeah, I haven't changed anything. Replaced cassette with 8spd 12-25, just like it was shipped with.

 

[Koga]

OK, so cassette is compatible, what about the chain is it 8 speed (more importantly is it not 10 speed which has a smaller width) ?

 

[Kookas]

OK, so cassette is compatible, what about the chain is it 8 speed (more importantly is it not 10 speed which has a smaller width) ?

Yep, chain is 8 speed. Got it fitted professionally after making a mess of the replacement before it, too.

This is what the guy at the LBS does to show me it's worn, moving the jockey cage side-to-side:

View: https://www.youtube.com/watch?v=-TX-hDD5_mY&feature=youtube_gdata_player

Does that look bad?

 

[Koga]

OK, cassette and chain replaced correctly, these were the easy options!
Ref your clip, it is a bit shaky so I find it difficult to comment on this, but I am sure other people will. Let's see what they come up with.

 

[Globalti]

That's a normal amount of movement; no derailleur is rigid. As long as nothing is loose that's fine.

OK so you replaced the inner cable but what about the OUTER where it curves around to the derailleur? That's the bit that wears out and gets all rusty and crudded up. Get you bike shop to sell you a metre of it, pre-cut into pieces the right length and get into the habit of changing it every six months.

 

[Kookas]

That's a normal amount of movement; no derailleur is rigid. As long as nothing is loose that's fine.

OK so you replaced the inner cable but what about the OUTER where it curves around to the derailleur? That's the bit that wears out and gets all rusty and crudded up. Get you bike shop to sell you a metre of it, pre-cut into pieces the right length and get into the habit of changing it every six months.

Alright, I'll do that on Wednesday. I might have managed to get it to shift, though - before I made that video, I tightened the derailleur at the bolt, because it was moving a bit at the bolt (even though the bolt itself didn't seem loose). Now it's not moving there at all.

The Decathlon guy told me off for not looking after it properly, and managed to persuade me to look after it better. So I'm maintaining it better now, cleaning the bike and such.

Before I just used to oil the chain and be done with it, but apparently with the dirt that builds up a grinding paste.

So I've just got to clean the dirt off the bike once a week before I oil the parts that need it.


By the way, do I just need to clean the chainstays, jockey wheels, etc, or does the chain itself need to be cleaned before it's oiled? Am I just trying to stop dirt falling off the chainstay into the chain and wearing it out?

And is it ok if it now shifts fine whilst it's upside-down? Knowing that I put a lot more stress on it when I'm actually pedalling.

 

[addictfreak]

Had similar issues with my winter ride recently. Rear mech must have done 10,000+ but still fine! I renewed the cables and outers re indexed it all and it's like new again.

 

[Globalti]

Don't clean the bike upside-down; soapy water will run straight into the steering bearings and rust them.

 

[Kookas]

Don't clean the bike upside-down; soapy water will run straight into the steering bearings and rust them.

Thanks for the tip, I cleaned it upright so I wouldn't wash oil into the saddle anyway.

I also found that whatever I used to clean the bike around the drivetrain got extremely oily to the point of being binned straight after - so I use kitchen towels to clean the drivetrain parts and chainstay now.

On that note, is it adequate to simply spray on some bike cleaning/mud displacing stuff and wipe it off with a kitchen towel instead of using a bucket of warm soapy water?

 

[Globalti]

Sounds like you're over-oiling that bike! Give it all a good strip down and clean then oil sparingly.

 

[deptfordmarmoset]

I think you need to look at some of the stuff he did in French. Then you'll have less of a problem.

I've seen his Cyrano de Bergerac several times and have no problem with it.

Avoid Green Card and Mon Pere ce Heros like the plague. They are schmaltzy Hollywood-esque stereotyping.

I hope I have helped with your problem.

What gear are you in on?