Is my chain too long?

08-24-2004, 12:30 PM

I just dusted off my old road bike (a 14 year old Raleigh Technium) and
started riding again. Last week the chain broke so I replace it with one of
the same size recommended by the LBS. I took it for a 15 miler over lunch
today and the chain came off the front sprocket no less than 3 times! This
doesn't seem right, so how do I fix it? I've got a chain tool so I could
remove a link or two, but it looks like there's no going back if that
doesn't help. I'm not even sure that's the problem since it is the same
length as the original one. I realize that this is a pretty general question
and not knowing the details of the parts involved it might be tough to
answer my question exactly. But is there some general principle that guides
these things that I could follow?

TIA,
Bob M

08-24-2004, 01:29 PM

Tue, 24 Aug 2004 16:30:59 -0400, <cgg8i4$om5$[Only registered and activated users can see links. ].ti.com>,
"Bob Marchese" <[Only registered and activated users can see links. ]> wrote:

>But is there some general principle that guides
>these things that I could follow?

The length of the chain is determined by wrapping the chain around
both of the largest sprockets, without going through the derailleur
pulleys, and adding one complete link.

[Only registered and activated users can see links. ]

Could it be the front derailleur over shifting or a bent chain ring?
--
zk

08-24-2004, 01:29 PM

Tue, 24 Aug 2004 16:30:59 -0400, <cgg8i4$om5$[Only registered and activated users can see links. ].ti.com>,
"Bob Marchese" <[Only registered and activated users can see links. ]> wrote:

>But is there some general principle that guides
>these things that I could follow?

The length of the chain is determined by wrapping the chain around
both of the largest sprockets, without going through the derailleur
pulleys, and adding one complete link.

[Only registered and activated users can see links. ]

Could it be the front derailleur over shifting or a bent chain ring?
--
zk

08-24-2004, 01:29 PM

Tue, 24 Aug 2004 16:30:59 -0400, <cgg8i4$om5$[Only registered and activated users can see links. ].ti.com>,
"Bob Marchese" <[Only registered and activated users can see links. ]> wrote:

>But is there some general principle that guides
>these things that I could follow?

The length of the chain is determined by wrapping the chain around
both of the largest sprockets, without going through the derailleur
pulleys, and adding one complete link.

[Only registered and activated users can see links. ]

Could it be the front derailleur over shifting or a bent chain ring?
--
zk

08-24-2004, 01:29 PM

Tue, 24 Aug 2004 16:30:59 -0400, <cgg8i4$om5$[Only registered and activated users can see links. ].ti.com>,
"Bob Marchese" <[Only registered and activated users can see links. ]> wrote:

>But is there some general principle that guides
>these things that I could follow?

The length of the chain is determined by wrapping the chain around
both of the largest sprockets, without going through the derailleur
pulleys, and adding one complete link.

[Only registered and activated users can see links. ]

Could it be the front derailleur over shifting or a bent chain ring?
--
zk

08-24-2004, 03:12 PM

"Zoot Katz" <[Only registered and activated users can see links. ]> wrote in message news:[Only registered and activated users can see links. ]...
>>
> The length of the chain is determined by wrapping the chain around
> both of the largest sprockets, without going through the derailleur
> pulleys, and adding one complete link.

No, wrap the chain around both the smallest sprockets
and cut it where it just starts to take up the derailleur
tension.

08-24-2004, 03:12 PM

"Zoot Katz" <[Only registered and activated users can see links. ]> wrote in message news:[Only registered and activated users can see links. ]...
>>
> The length of the chain is determined by wrapping the chain around
> both of the largest sprockets, without going through the derailleur
> pulleys, and adding one complete link.

No, wrap the chain around both the smallest sprockets
and cut it where it just starts to take up the derailleur
tension.

08-24-2004, 03:12 PM

"Zoot Katz" <[Only registered and activated users can see links. ]> wrote in message news:[Only registered and activated users can see links. ]...
>>
> The length of the chain is determined by wrapping the chain around
> both of the largest sprockets, without going through the derailleur
> pulleys, and adding one complete link.

No, wrap the chain around both the smallest sprockets
and cut it where it just starts to take up the derailleur
tension.

08-24-2004, 03:12 PM

"Zoot Katz" <[Only registered and activated users can see links. ]> wrote in message news:[Only registered and activated users can see links. ]...
>>
> The length of the chain is determined by wrapping the chain around
> both of the largest sprockets, without going through the derailleur
> pulleys, and adding one complete link.

No, wrap the chain around both the smallest sprockets
and cut it where it just starts to take up the derailleur
tension.

08-24-2004, 05:10 PM

On Tue, 24 Aug 2004 16:30:59 -0400, Bob Marchese wrote:

> I just dusted off my old road bike (a 14 year old Raleigh Technium) and
> started riding again. Last week the chain broke so I replace it with one of
> the same size recommended by the LBS. I took it for a 15 miler over lunch
> today and the chain came off the front sprocket no less than 3 times! This
> doesn't seem right, so how do I fix it? I've got a chain tool so I could
> remove a link or two, but it looks like there's no going back if that
> doesn't help. I'm not even sure that's the problem since it is the same
> length as the original one. I realize that this is a pretty general question
> and not knowing the details of the parts involved it might be tough to
> answer my question exactly. But is there some general principle that guides
> these things that I could follow?

Is there reason to suspect that the chain you replaced was installed
properly? Or not?

The chain dropping off the front chainring can be caused by several
things. The first thing to check is front derailleur adjustment. The
next thing is to check for wear on the chainrings themselves. If the
teeth are very sharp, and very thin, probably the inter-tooth distance has
been stretched due to chain wear. Since this is a new chain on old rings,
that would tend to support my guess.

An extra link is the least likely cause of shifting trouble (OK, 3-4 extra
links might be a problem, but one, no). Misadjusted shifters are the most
likely, and chainring wear is next.

--

David L. Johnson

__o | "Business!" cried the Ghost. "Mankind was my business. The
_`\(,_ | common welfare was my business; charity, mercy, forbearance,
(_)/ (_) | and benevolence, were, all, my business. The dealings of my
trade were but a drop of water in the comprehensive ocean of my
business!" --Dickens, "A Christmas Carol"