Newbie needs help: chain popped off front derailleur



M

Mohap

Guest
Today I took my bike in to get looked at because it was
rattling on 7th and 8th gear (rear derailleur).

It was working great when I took it home, everything was
fine.

But I was climbing a hill and I was on gear 2 (front) and
quickly shifted down to 1, and after that the chain popped
off the front derailleur teeth.

How do I put it back on? It's very tight and I can't get it
to wrap around any one of the teeths. Is there a way to
loosen it?

Does this happen from time to time and just something I have
to learn to fix? Or could this be a defective bike? I have
until July 11th to exchange
it. Should I take the opportunity?

Also, it doesn't pedal (it's jammed) but you can probably
infer that.

thanks.
 
Originally posted by Mohap
Today I took my bike in to get looked at because it was
rattling on 7th and 8th gear (rear derailleur).

It was working great when I took it home, everything was
fine.

But I was climbing a hill and I was on gear 2 (front) and
quickly shifted down to 1, and after that the chain popped
off the front derailleur teeth.

How do I put it back on? It's very tight and I can't get it
to wrap around any one of the teeths. Is there a way to
loosen it?

Does this happen from time to time and just something I have
to learn to fix? Or could this be a defective bike? I have
until July 11th to exchange
it. Should I take the opportunity?

Also, it doesn't pedal (it's jammed) but you can probably
infer that.

thanks.

Your chain is jammed due to overshooting the small front chain ring. The Front derailer stop should prevent this most of the time.
N-Gear sells a device called JumpStop that prevents this from ever happening.
You will need to un-jam your chain by working it out of the spot by the bottom bracket shell. This can be messy if the chain is gritty and oily, so be ready clothing wise and hand cleaner... etc.
You will need to grab a section of the chain towards the hub and pull it forward to clear the jam. You can then slide the chain back on and get the shifters working again. Under extreme conditions some links in the chain may have been kinked. You may need to replace or repair them.
It is very difficult to tell about the condition of the bicycle and defects, but it sounds like you need to practice shifting and learing the basics of adjusting your bicycle.

I suggest you read your owners manual and the articles from Sheldon Brown's web pages on shifters and adjustments:

<http://www.sheldonbrown.com/gears.html>

<http://www.sheldonbrown.com/derailer-adjustment.html>
 
Thanks for the informative links and your help. I tried what
you said...

I got another problem. I put the chain back on, but it keeps
slipping off when I pedal.

I shifted to 3, and put the chain back on to the largest
sprocket, but then when I downshifted to 2, the chain
slipped to the smallest sprocket (1). and then when I
shifted to 1 and pedaled, the chain fell off again.

And it makes the bad rattling noise all the time.

Could the derailleur been whacked out of alignment? Thanks.

"daveornee" <[email protected]> wrote in
message news:[email protected]...
> Mohap wrote:
> > Today I took my bike in to get looked at because it
> > was rattling on
7th
> > and 8th gear (rear derailleur). It was working great
> > when I took it home, everything was fine. But I was
> > climbing a hill and I was on gear 2 (front) and
> > quickly shifted down to 1, and after that the chain
> > popped off the front derailleur teeth. How do I put it
> > back on? It's very tight and I can't get it to wrap
> > around any one of the teeths. Is there a way to loosen
> > it? Does this happen from time to time and just
> > something I have to learn to fix? Or could this be a
> > defective bike? I have until July 11th to exchange
> > it. Should I take the opportunity? Also, it doesn't
> > pedal (it's jammed) but you can probably infer
> > that. thanks.
>
>
>
> Your chain is jammed due to overshooting the small front
> chain ring. The Front derailer stop should prevent this
> most of the time. N-Gear sells a device called JumpStop
> that prevents this from ever happening. You will need to
> un-jam your chain by working it out of the spot by the
> bottom bracket shell. This can be messy if the chain is
> gritty and oily, so be ready clothing wise and hand
> cleaner... etc. You will need to grab a section of the
> chain towards the hub and pull it forward to clear the
> jam. You can then slide the chain back on and get the
> shifters working again. Under extreme conditions some
> links in the chain may have been kinked. You may need to
> replace or repair them. It is very difficult to tell about
> the condition of the bicycle and defects, but it sounds
> like you need to practice shifting and learing the basics
> of adjusting your bicycle.
>
> I suggest you read your owners manual and the articles
> from Sheldon Brown's web pages on shifters and
> adjustments:
>
> <http://www.sheldonbrown.com/gears.html>
>
> <http://www.sheldonbrown.com/derailer-adjustment.html>
>
>
>
> --
 
On Sun, 04 Jul 2004 23:10:05 GMT, "Mohap" <[email protected]> wrote:

>Thanks for the informative links and your help. I tried
>what you said...
>
>I got another problem. I put the chain back on, but it
>keeps slipping off when I pedal.
>
>I shifted to 3, and put the chain back on to the largest
>sprocket, but then when I downshifted to 2, the chain
>slipped to the smallest sprocket (1). and then when I
>shifted to 1 and pedaled, the chain fell off again.
>
>And it makes the bad rattling noise all the time.
>
>Could the derailleur been whacked out of alignment?

Your description is consistent with a misadjusted front der;
in particular, the stop for the travel towards the small
sprocket almost certainly isn't correctly adjusted, and
either the cable has slipped at the clamp, or the cable
adjuster at the shifter needs to be run out a bit.

Here's another link to look at:

http://www.parktool.com/repair_help/howfix_frontderail-
leur.shtml

--
Typoes are a feature, not a bug. Some gardening required to
reply via email. Surrealism is a pectinated ranzel.
 
Originally posted by Werehatrack
On Sun, 04 Jul 2004 23:10:05 GMT, "Mohap" <[email protected]> wrote:

>Thanks for the informative links and your help. I tried
>what you said...
>
>I got another problem. I put the chain back on, but it
>keeps slipping off when I pedal.
>
>I shifted to 3, and put the chain back on to the largest
>sprocket, but then when I downshifted to 2, the chain
>slipped to the smallest sprocket (1). and then when I
>shifted to 1 and pedaled, the chain fell off again.
>
>And it makes the bad rattling noise all the time.
>
>Could the derailleur been whacked out of alignment?

Your description is consistent with a misadjusted front der;
in particular, the stop for the travel towards the small
sprocket almost certainly isn't correctly adjusted, and
either the cable has slipped at the clamp, or the cable
adjuster at the shifter needs to be run out a bit.

Here's another link to look at:

http://www.parktool.com/repair_help/howfix_frontderail-
leur.shtml

--
Typoes are a feature, not a bug. Some gardening required to
reply via email. Surrealism is a pectinated ranzel.

Yes!
It could also be that the chain has some bent links that are biased to shift past the smallest chain ring.
When you put the chain on and get the derailers shifted so that it run smooth, does it continue to run smoothly when you are off the bicycle and pedal backwards?
If not, your chain may have some bent links that need repair of replacement.
I suggest you take it back to the shop where you bought it for further examination.
I also saw these symptoms with a lose bottom bracket... and the list goes on... but without actually looking at the "patient" and feeling and hearing the symptoms ... I just won't turn into prescribing more cures... :}
 
Went to the LBS. Turned out to be a misaligned front
dereailer.. How it happened is kindof a mystery.The tech
said cos I might have accidentally kicked it, but I'm
sure I didn't.

Could it be because I was trying to force the pedals to turn
when it was jammed??

Also they said that the jumpstop won't work on my kind of
bike because of the way the derailleur is installed. They
said that it's pretty common on mountain and hybrids (I have
a bianchi boardwalk hybrd).

"daveornee" <[email protected]> wrote in
message news:%[email protected]...
> Werehatrack wrote:
> > On Sun, 04 Jul 2004 23:10:05 GMT, "Mohap"
> > <[email protected]> wrote:
> > >Thanks for the informative links and your help. I
> > >tried what you said...
> > >
> > >I got another problem. I put the chain back on, but
> > >it keeps slipping off when I pedal.
> > >
> > >I shifted to 3, and put the chain back on to the
> > >largest sprocket,
but
> > >then when I downshifted to 2, the chain slipped to
> > >the smallest sprocket (1). and then when I shifted to
> > >1 and pedaled, the chain
fell
> > >off again.
> > >
> > >And it makes the bad rattling noise all the time.
> > >
> > >Could the derailleur been whacked out of alignment?
> > Your description is consistent with a misadjusted
> > front der; in particular, the stop for the travel
> > towards the small sprocket almost certainly isn't
> > correctly adjusted, and either the cable has slipped
> > at the clamp, or the cable adjuster at the shifter
> > needs to be run out a bit. Here's another link to look
> > at:ttp://www.parktool.com/repair_help/howfix_frontderail-
> > ttp://www.parktool.com/repair_help/howfix_frontderail-
> > leur.shtml
> > --
> > Typoes are a feature, not a bug. Some gardening
> > required to reply via email. Surrealism is a
> > pectinated ranzel.
>
>
>
> Yes! It could also be that the chain has some bent links
> that are biased to shift past the smallest chain ring.
> When you put the chain on and get the derailers shifted so
> that it run smooth, does it continue to run smoothly when
> you are off the bicycle and pedal backwards? If not, your
> chain may have some bent links that need repair of
> replacement. I suggest you take it back to the shop where
> you bought it for further examination. I also saw these
> symptoms with a lose bottom bracket... and the list goes
> on... but without actually looking at the "patient" and
> feeling and hearing the symptoms ... I just won't turn
> into prescribing more cures... :}
>
>
>
> --