Chain Kept Falling Off, I Tinkered With The Bike Too Much..



Uawadall

Well-Known Member
Jun 14, 2015
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I was in a group ride yesterday and the chain kept falling off on the big ring. I tried adjusting the limiter screws and made things worse, the chain wouldn't shift to the big ring. I loosened the cable at the back of the bike and further messed up the shifting. After that, I had to loosen the rear derailleur do to the wiring housing at the bottom of the top tube coming off. Also, I noticed the barrel adjuster at the top are loose and won't tighten now and one of the pieces holding it in place was chipped(i super glued it together since).Here is a list of the problems, any idea where to start?...

1.The wiring for the shifters have no tension in them, they are very loose

2. The barrel adjusters at the top are loose and won't tighten.

3. The bike won't shift at all in the big ring and only up 2 gears in the low one
 

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This is clearly a case for...CampyBob! Having the latest Zinn and Downs books on bicycle repair won't hurt you at all, plus YouTubehas a lot of videos on the topic.


Bob
 
Sorry, this isn't CampyBob.

It looks like the reason the chain won't go into the big ring is that the front derailleur slipped down the seat tube so the outer plate of the cage is hitting the ring.

Until I saw the photos I was going to say the first thing you should do is find out if the front derailleur is knocking the chain off the ring or if it's something else. Usually, something else means a bent chain, a bent chainring, or something happened to knock the chain line out of whack. But between the photo and your description, it sounds like you went ahead and assumed it had something to do with the derailleur adjustment, and now there is so much wrong here I'm simply going to point you to this web page: http://www.parktool.com/blog/repair-help/front-derailleur-adjustment

And this one, too: http://www.parktool.com/blog/repair-help/chainline-concepts

And if you can't figure it out, take it to your local shop. If there are no broken parts, they should be able to fix it for less than $20.
 
OBC is the shimaNO go-to guy...not me. I do the Campagnolo thing.

OP, watch OBC's video links and print out and read through Swami's shimaNO technical documents. If, after watching and reading those you are still unsure how to proceed, take your bike back to where you purchased it or to a local bike shop.

It sounds like you pretty much have both derailleurs out of adjustment and possibly a broken part that's in need of replacement. Adjusting the derailleurs is a task all cyclists should learn how to accomplish and it's really not difficult after the basics are understood.
 
Uawadall said:
I was in a group ride yesterday and the chain kept falling off on the big ring. I tried adjusting the limiter screws and made things worse, the chain wouldn't shift to the big ring. I loosened the cable at the back of the bike and further messed up the shifting. After that, I had to loosen the rear derailleur do to the wiring housing at the bottom of the top tube coming off. Also, I noticed the barrel adjuster at the top are loose and won't tighten now and one of the pieces holding it in place was chipped(i super glued it together since).Here is a list of the problems, any idea where to start?...

1.The wiring for the shifters have no tension in them, they are very loose

2. The barrel adjusters at the top are loose and won't tighten.

3. The bike won't shift at all in the big ring and only up 2 gears in the low one
FWIW. If you haven't had the time to check ANY of the suggested links ...

Let me tell you that (at first) your derailleur appeared to be mounted TOO HIGH above the outer chainring because I was not familiar with the shape of the Tiagra's front derailleur outer plate (I guess that I was also confused by the upside-down pictures!) ... oldbobcat is correct that it will be impossible to shift onto the outer ring in the pictured configuration.

Regardless, the visible gap between the teeth & the bottom of the front derailleur's outer cage should be roughly 2mm -- a typical, single gauge spoke is 2mm in diameter if you don't have a metric ruler OR if you can readily visualize a phantom spoke placed in between the teeth & the lower edge of the front derailleur's cage.

FYI. As oldbobcat suggested, CHECK www.parktool.com to read how to adjust your derailleurs AND the cable tension.

BTW. If you TRULY want better, cleaner shifting, then use Campagnolo shifters with your Shimano derailleurs!!! :)
 
alfeng said:
BTW. If you TRULY want better, cleaner shifting, then use Campagnolo shifters with your Shimano derailleurs!!! :)
I just swallowed my vomit. :wacko:
 
Okay, so I got all the go-to guys wrong. There must be at least one go-to lady as well, in these forums?

Seriously, I too need to learn derailleur adjustment. I too will watch the videos and read the manuals.

I did advise Uawadall to get the Zinn and Downs books.

Thanks a ton!

Bob
 
I've gotten most of the lower gears to shift. I'm still reading the info provided and trying to figure out what I did wrong with the from derailleur. The barrel adjusters tighten and loosen again, but the left shifter is very stiff and doesn't move the front derailleur at all.

BTW, is it possible to use a bike with one shifter not working correctly without damaging the bike?
 
"...but the left shifter is very stiff and doesn't move the front derailleur at all."

How old is the bike? How many miles on it?

It's is possible you have a worn cable or somehow damaged your cable. It could also be the shift cables are just in need of cleaning/lubricating.

If the adjusting barrels are not holding adjustment they are either screwed out too far or they are FUBAR and in need of replacement. Although kind of hard to ruin up, I've seen guys do just that. They are just plastic and aluminum in most cases and will not suffer abuse.

Yes, you can ride with one of both derailleurs not functioning or shifting poorly without doing damage. Shifts should be performed with less pedal pressure than if they were working properly to prevent 'possible' abuse to the chain, the the chainring teeth and cassette teeth. And I would not recommend riding around with your derailleurs in that state for any more miles than necessary.

It sounds like you should wheel on into your local bike store and have it looked at.
 
oldbobcat said:
I just swallowed my vomit. :wacko:
LOL!

I would have ALSO suggested SRAM shifters (well, THERE's a reason to vomit!!) as an alternative to the Tiagra shifters (which many people now say are pretty good), but they would apparently require new derailleurs ...

FWIW/BTW. I've got to say it ...

I love how the cycling cognoscenti (aka "paid shills") have embraced 1x drivetrains ...

If one observes SRAM's technological arc, then I don't think it is a leap to suggest that the 1x (which is certainly viable for sponsored CX configurations OR for people who can have a dedicated bike for different riding occasions) was a "why not (try to sell it to the unwashed masses)?" because SRAM's bean counters possibly-and-probably-so-apparently figured it was easier to sell THAT than to add trim to their front shifters ...

After all, MTB shifters don't need-or-have trim.

Of course, there is an obvious reason why MTB shifters don't have-or-need trim ...

So, for the time being, the emperor still has new clothes.
 
CAMPYBOB said:
That only works with a 1 MM air gap.
Ack ...

Spoken like an-almost-or-now out-of-the-closet Wobbly (( :eek:)) for whom the party line is gospel ...

There are times when YOU shouldn't trust the dictates of the PTB from (m)any walk(s)-fo-life ...

I fear that you are going to take the next step ...

AND that you'll also become an open advocate of Obamacare + Barry's other dictates!?!

It's not too late for you YOU to "Step away from the Chalupa!"
 
Uawadall said:
I've gotten most of the lower gears to shift. I'm still reading the info provided and trying to figure out what I did wrong with the from derailleur. The barrel adjusters tighten and loosen again, but the left shifter is very stiff and doesn't move the front derailleur at all.

BTW, is it possible to use a bike with one shifter not working correctly without damaging the bike?
Well, in addition to the good suggestion by CAMPYBOB that your cable(s) may need to be lubed/cleaned OR (simply) changed ...

Presuming you have adjusted the front derailleur's height, what YOU need to do is
  • to loosen the bolt on the front derailleur
  • while pulling lightly on the front derailleur's cable
  • press the lever's inner paddle (the thumb lever on Campagnolo shifters) until it stops "clicking"
  • now, while minimizing the slack in the cable to the best of your ability, secure the front derailleur cable
  • and then, see if pressing inward on the larger lever (the "brake" lever) moves the front derailleur
YOU can test-and/or-assess the cable-and-shifter before you secure the cable to the front-or-rear derailleur by actuating the shifter AND simply holding a portion of the cable where it exits the housing -- it should move freely ...

Checking the cable when it is not connected will give you a sense of how much resistance is in the shifter+housing+cable assembly ...

The resistance should be minimal-to-non-existent.

IMO (others have disagreed on this point), replacing the parallel stranded housing with coiled brake cable housing (the ends need to be "finished" by deburring otherwise you will simulate the ends of a parallel stranded housing!!!) OR (if you have deeper pockets) AZTEC-or-equivalently-expensive cable housing should minimize the likelihood of fraying the cable near-or-inside the shifter.

BTW. While it is generally less efficient for the rider to have a non-functioning shifter, you certainly do not need BOTH shifters to be functioning to ride your bike ... damage will only occur if the shifter places the derailleur in a position which is adverse to the drivetrain otherwise functioning properly ...

As you may-or-may-not know, SRAM has chosen to eschew the front derailleur on MANY of its configurations ...

If your front shifter is actually "broken" then you can either replace it OR "lock" the front derailleur over one-or-the-other-chainring by adjusting the inner stop, accordingly, OR (as a "final" option) simply remove the front derailleur.
 
Uawadall said:
I've gotten most of the lower gears to shift. I'm still reading the info provided and trying to figure out what I did wrong with the from derailleur. The barrel adjusters tighten and loosen again, but the left shifter is very stiff and doesn't move the front derailleur at all.

BTW, is it possible to use a bike with one shifter not working correctly without damaging the bike?
Any monkey that can reasonably follow directions can tune a rear derailleur, but getting the front to work right takes finesse. Study the Park Tool guide carefully. And, yeah, you can ride around in the small chainring all you want, and you won't hurt anything. But you'll enjoy the ride more if you fix it, or get it fixed.

If your bike has external cable routing, you should be able to shift to the big ring by just pulling on the cable. Can you do this?
 
Quote by Swami:
"CampyBob fills that role.

Wait! Wut?

I thought you were the CF's Queen Of ShitmaNO?

Miata? Check!
Assless chaps? Check!
Lives in Caleefornya? Check!

14012d1373994117-i-don-t-like-fwd-cars-miataposter.jpg
 
CAMPYBOB said:
"...but the left shifter is very stiff and doesn't move the front derailleur at all."

How old is the bike? How many miles on it?

It's is possible you have a worn cable or somehow damaged your cable. It could also be the shift cables are just in need of cleaning/lubricating.

If the adjusting barrels are not holding adjustment they are either screwed out too far or they are FUBAR and in need of replacement. Although kind of hard to ruin up, I've seen guys do just that. They are just plastic and aluminum in most cases and will not suffer abuse.

Yes, you can ride with one of both derailleurs not functioning or shifting poorly without doing damage. Shifts should be performed with less pedal pressure than if they were working properly to prevent 'possible' abuse to the chain, the the chainring teeth and cassette teeth. And I would not recommend riding around with your derailleurs in that state for any more miles than necessary.

It sounds like you should wheel on into your local bike store and have it looked at.
I bought the bike used and it belonged to one of the shops riding buddies before who had it for a year. I'm guessing he put at least between 2-3,000 and I've put 1700 miles on it. The screws and bolts are aged, the plastic piece holding the barrel adjuster appears to be totally busted. I'm working on becoming an architect annam very good with drawing up schematics, but I've never been great with my hands.Saying that, its actually feels good to learn some of the basics about bike maintenance. I'll have to bring it into a shop tomorrow and see if I can get the part replaced.
 
oldbobcat said:
Any monkey that can reasonably follow directions can tune a rear derailleur, but getting the front to work right takes finesse. Study the Park Tool guide carefully. And, yeah, you can ride around in the small chainring all you want, and you won't hurt anything. But you'll enjoy the ride more if you fix it, or get it fixed.

If your bike has external cable routing, you should be able to shift to the big ring by just pulling on the cable. Can you do this?
It won't shift into the big ring while tugging it.
 
CAMPYBOB said:
Quote by Swami:
"CampyBob fills that role.

Wait! Wut?

I thought you were the CF's Queen Of ShitmaNO?

Miata? Check!
Assless chaps? Check!
Lives in Caleefornya? Check!

14012d1373994117-i-don-t-like-fwd-cars-miataposter.jpg
My Miata is like your CampagNOlo - I don't have any ;) The current wee-beastie is an S2000.

The assless chaps are all yours, given you class a Harley as a motorcycle and not as a two wheeled tractor.

Campy by name, camp by nature.
 

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