Will a Worn Out Chain...?

[Dadx2mj]

Can a worn out chain cause shifting problems on an external 7 speed bike? I have a Giant Simple Seven that has not shifted properly since I bought it off Craig's List. The shifter has been replaced and the hub rebuilt the derailleur hanger looks good as does the derailleur. The cable has been replaced twice and been adjusted more times than you can count by me and the mechanic at the LBS. It shifts between 1st and 2nd and 6th and 7th fine both up and down. Problem lies when shifting anywhere from 2nd to 5th gear. I can adjust the cable to where it either takes two clicks to get it to shift up and then requires on shift down to get the shifter in the proper spot for the gear it is in and not make any chain noise or I adjsut it to where it only takes one click to go up but then two down to make it shift down followed by one up to make it run quiet and smooth. The LBS mechanic who I have lost all faith in tells me I need a new chain and maybe a new cassette to fix this issue. Is there any merit to this or is he just trying to sell me more new parts. Thanks for any help and advice with this

 

[dxtom]

You may want check alignment of the link between the frame and derailer. It might be out alignment . Park tool has a tool to check it. I've seen this problem on road bike. Good Luck.

 

[Frankie plekhand]

What shifter and derailleur are u using? Maybe theyre not compatible, if u use a sram twist shifter like a 3.0 /5.0 /7.0 u should use a sram derailleur too its not compatible with a shimano derailleur. They use a different ratio.
U can use a sram shifter with a shimano derailleur but only if its from the MRX series

Frank

Customize!

 

[ifitsfreeitsforme]

yep, sounds like incompatible components.

 

[Dadx2mj]

When I got the bike it had the stock Shimano Revo Twist Shifter and Shimano Tourey Megarange derailleur. I replaced the shifter with a Shimano thumb lever shifter. The odd shifting was the same with the stock equipment and the new shifter.

So I am getting the feeling no one thinks a worn out chain and or cassette could be the cause of this?

 

[user 135]

Change to friction shift....no problems then.

 

[user 135]

Worn out cassettes and chains most noticeably cause a skipping issue first. I dont' think they would cause your odd shifting. Does this bike have an actual derailer hanger or is the hanger integrated into the derailer?

 

[Frankie plekhand]

It shouldnt matter if your chain/freewheel is worn, you only notice that when you put a lot of force on the pedals, then you feel the chain.
Hmmm thats weird.. it should work with those parts but it doesnt...
Have you checked for play in the derailleur, does the cage move from left to right? It shouldnt, only if its worn out.

Customize!

 

[Dadx2mj]

Thanks for the help guys.

The bike does have a hanger which is just a short link that goes between the frame and the derailleur. I have checked it before but will check that again and look at the derailleur more closely.

 

[user 135]

Looking at your bike, I am not a fan of that style of derailer attachment. I would rather see the derailer directly attached to the bike. I think they do that to compensate for those MegaRange freewheels with 34t.

It looks like your cable and housing could be a little longer. Cable routing has been known to cause shifting problems.

Here is a great read on derailer adjustment. http://sheldonbrown.com/derailer-adjustment.html

 

[Dadx2mj]

That picture is when it had the older twist shifter on it and before it had the cable replaced, the cable was a little short once I put the ape hanger bars on it. Now the cable is longer and one of the other guys at the LBS has told me the cable length could be the problem. His explanation is that when cables get that long they have more "stretch" in them and sometimes it takes two clicks to over come the stretch. Not sure I buy that as I have seen some of these stretched out bikes with cables longer than mine and they seem to shift just fine.

 

[user 135]

That may be the case on a new cable but not likely the main factor. Is the cable housing made for shift cables? Like this?

 

[Bicycle808]

I'd approach this methodically. Start with the easy fixes and/o the stuff that falls under routine maintenance of consumable components.....

-First, make sure you have decent cable tension. If the cable is too loose, shifting will suffer.
-As Clancy mentioned, if your shift cable is too short, you'll have consistent problems where a slight turn of the bars may cause issues, like ghost-shifting and other weirdness.
-If you haven't yet, it would probably make sense to replace the cable with a decent new shift cable. Change the housing, too. Make sure you cut the housing and cable to a length where there's enough slack to move the bars, but not excessively so.
-One of the main causes of indexed shifting problems is the derailer hanger, which was already mentioned above. If the hanger is tweaked, your system won't index correctly. I'm guessing/hoping the Giant uses a replaceable hanger?
-A worn chain and/or worn sprockets can cause the chain to jump and studder. If the chain is stretched and the cogs are shark-finned, replace them.
-Other things to check: if this is a cassette (not a freewheel) check that the lockring is sufficiently tight. A loose lockring will allow the sprockets to move laterally, which will cause shifting issues. If it's a freewheel, check for excessive play I n the hub. Heck, check for that if it's a cassette, too.
-Being that you went from a twist to a thumb shifter, and the problem existed across both set-ups, we can be reasonably sure that the shifter's ok. However, if your derailer is beat-up or bent or the springs are shot, that may well be your problem. Long-cage index-compatible Shimano rear derailers are common and cheap; just stay away from some of the latest designs, as pull ratio has changed over the years.

HTH
=-Rob

(Right now, I'm off to the co-op to mess with stuff just like this....)

 

[Dadx2mj]

Thanks again for all the advice guys. I just spent the last hour or two working on it. I pulled the derailleur off to check it out and although it does seem a lil loose or sloppy I dont see anything really wrong with it. The hanger appears to be straight and not tweaked at all. The cable and housings have all been replaced twice now and are plenty long enough. I went through all the adjustments and am right back where I started from. I am just stumped. Maybe the derailleure is just worn out. I think I might take it to a different LBS that is not quite so local but has a much better reputation than the one that is just two miles from where I live.

 

[Bicycle808]

Loose/sloppy derailer? That'll definitely cause problems on an indexed system.

 

[Dadx2mj]

Okay so I started looking at derailleurs online and man these things are dirt cheap. I then called my LBS and ask them if they have it in stock. I hear the guy who answered the phone asking someone else about it and the guy replied to him saying they did have it and it was $15. The guy then gets back on the phone and tells me he has them from $30 and up. I am SO DONE with that LBS. Looking online again I dont see the exact same derailleur that I have now. If I get a Shimano 7 speed derailleur that looks close will it work with what I have on the bike now?

 

[Frankie plekhand]

If its a 7 speed, it works


Customize!

 

[mikeeebikey]

It is the housing!
The cable housing must be for index shifting.
A worn chain will ride up, or extra gear lower, then drop back. Or, will not want to climb, depending how it is adjusted.
As you noted, skipping while pedaling is the cog.
But try some new s.I.s. housing, nake sure you use housing ends/caps, or the wire sheath will do non fun stuff!

 

[Bicycle808]

It is the housing!
The cable housing must be for index shifting.
A worn chain will ride up, or extra gear lower, then drop back. Or, will not want to climb, depending how it is adjusted.
As you noted, skipping while pedaling is the cog.
But try some new s.I.s. housing, nake sure you use housing ends/caps, or the wire sheath will do non fun stuff!

This is true, but if the cable's already been replaced with new twice, i bet he's already got the compressionless index-compat housing. Few places are stocking friction-only derailer housing anymore.

If the old derailer is sloppy, that's probably the culprit.

Dadx2mj, most Shimano derailer that were made in the past 20 years will work... and any of the older ones designed for indexing will work, too. Exceptions include some early Dura-Ace, and the new "Dyna-sys" mtb 10speeds, plus the 11speed garbage. But any Shimano rear derailer designed to index with 6-, 7-, 8-, or 9-speed will work with the shifters. You'll need to figure out what your chainwrap capacity needs are, but the easy thing to do would be to get one like whatever you're replacing. If you change cage lengths, you may not have enough ability to take up slack with a short cage, and you will likely need to add a few links if you use a longer cage. It ain't rocket science, but if you take a few minutes to figure out what you need, you will avoid headaches.

 

[Dadx2mj]

Pretty sure the cable housing is correct. It was replaced by the LBS both times.. That being said I am going to pull an end off and make sure it has the layers shown above. This LBS has proven to me to be very unreliable. First time they did the cable they quoted me $12 over the phone to install the cable. I thought that was a great price. When I went to pay the bill was suddenly $44