Chain Skip Question



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Dave M Wyman

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Help! I put a new chain on my bike, along with a new cassette. It's a SCRAM chain designed for bike
with nine cogs, like mine, and is the same kind of chain I had on before.

The chain skips (well, it drops down a cog- the the third largest to the fourth - and then back up).
It does this when I'm in the middle chainring and when I'm applying power up a steep hill.

It doesn't seem to skip in the big chainring or the smallest. Just the
middle. I've tried three cassettes, now - the new one, one that never had much use, and my old one.

Any idea on what could be causing this? Could it be the middle chainring? Or is the chain a more
likely culprit? (Rhetorical question: How much more money do I have to spend?!?)

Thanks,

Dave

--
http://www.davewyman.com

This mail is a natural product. The slight variations in spelling and grammar enhance its individual
character and beauty and in no way are to be considered flaws or defects.
 
"Dave M Wyman" <[email protected]> schrieb im Newsbeitrag news:u78Ha.212160$M01.95035@sccrnsc02...
> Help! I put a new chain on my bike, along with a new cassette. It's a SCRAM chain designed for
> bike with nine cogs, like mine, and is the same kind of chain I had on before.
>
> The chain skips (well, it drops down a cog- the the third largest to the fourth - and then back
> up). It does this when I'm in the middle chainring and when I'm applying power up a steep hill.
>
> It doesn't seem to skip in the big chainring or the smallest. Just the
> middle. I've tried three cassettes, now - the new one, one that never had much use, and my old
> one.
>
> Any idea on what could be causing this? Could it be the middle chainring? Or is the chain a more
> likely culprit? (Rhetorical question: How much more money do I have to spend?!?)
>

It sounds like your r-drlr is out of adjustment. There are three adjustment screws on it. Two are
just like the adjustment on the f-drlr, high stop and low stop. The third governs how far the jockey
wheel sits from the casette and how much tension is on the cog-shain interface. Try adjusting this
one out. Take a look at Leonard Zinn's "Zinn and the Art of Mountainbike Maintenance" for more info.

-Dave
 
"Dave M Wyman" <[email protected]> wrote in message news:u78Ha.212160$M01.95035@sccrnsc02...
> Help! I put a new chain on my bike, along with a new cassette. It's a SCRAM chain designed for
> bike with nine cogs, like mine, and is the same kind of chain I had on before.
>
> The chain skips (well, it drops down a cog- the the third largest to the fourth - and then back
> up). It does this when I'm in the middle chainring and when I'm applying power up a steep hill.
>
> It doesn't seem to skip in the big chainring or the smallest. Just the
> middle. I've tried three cassettes, now - the new one, one that never had much use, and my old
> one.
>
> Any idea on what could be causing this? Could it be the middle chainring? Or is the chain a more
> likely culprit? (Rhetorical question: How much more money do I have to spend?!?)
>

Dave S. may also be correct, but it sounds like your rear cable tension isn't quite right. Try
adding tension to the cable at the derailleur 1/8 turn (at most) at a time. Usually when the chain
moves back and forth the cause is that the cable has too much slack, so it can't offset the springs
in the derailleur. Too much tension and it will jump cogs.

Count your turns and remember them, just in case you need to reset the tension. Happy fiddling.
 
"Cameron" <[email protected]> wrote in message
news:[email protected]...
>
> "Dave M Wyman" <[email protected]> wrote in message
news:u78Ha.212160$M01.95035@sccrnsc02...
> > Help! I put a new chain on my bike, along with a new cassette. It's a SCRAM chain designed for
> > bike with nine cogs, like mine, and is the same kind of chain I had on before.
> >
> > The chain skips (well, it drops down a cog- the the third largest to the fourth - and then back
> > up). It does this when I'm in the middle chainring and when I'm applying power up a steep hill.
> >
> > It doesn't seem to skip in the big chainring or the smallest. Just the
> > middle. I've tried three cassettes, now - the new one, one that never had much use, and my old
> > one.
> >
> > Any idea on what could be causing this? Could it be the middle chainring? Or is the chain a more
> > likely culprit? (Rhetorical question: How much more money do I have to spend?!?)
> >
>
> Dave S. may also be correct, but it sounds like your rear cable tension
isn't
> quite right. Try adding tension to the cable at the derailleur 1/8 turn
(at most)
> at a time. Usually when the chain moves back and forth the cause is that
the
> cable has too much slack, so it can't offset the springs in the
derailleur. Too
> much tension and it will jump cogs.
>
> Count your turns and remember them, just in case you need to reset the
tension.
> Happy fiddling.
>
Another possibility is the alignment or the rear hanger to the wheel. Get to the LBS and have them
screw a tool into the thread for the rear mech and then the hanger can be adjusted so it is parallel
to the rear wheel, top bottom and directly rear. It is surprising just how many rear hangers are
out. My LBS that is closing in 2 weeks used to check all new bikes and found many out, some quite
bad. I have a Scott GZero Strike mine was ok. I had a nasty crash and my rear gear started this. I
changed the cable and it was about 90% right then had the hanger aligned and so far OK. Worth a try
and only takes 5 mins. One nasty incident I have had was the rear cassette coming loose, check the
nut! Clean the thread and locktight it.

Kent
 
On Mon, 16 Jun 2003 00:24:58 GMT, Dave M Wyman <[email protected]> wrote:

[snip ****]

Should have got an SS. :p

Peace, Bill The mind serves properly as a window glass rather than as a reflector, that is, the mind
should give an immediate view instead of an interpretation of the world.
:-]
 
Bill Wheeler <[email protected]> spoke thusly...
> On Mon, 16 Jun 2003 00:24:58 GMT, Dave M Wyman <[email protected]> wrote:
>
> [snip ****]
>
> Should have got an SS. :p
>
> Peace, Bill The mind serves properly as a window glass rather than as a reflector, that is, the
> mind should give an immediate view instead of an interpretation of the world.
> :-]
>

Now, you can't tell me SS are not going to get chain skip. i had a motorcycle with a very worn
sprocket. no matter what i had the tension set to, it skipped. and would you belive Honda wanted to
charge $23 for the damn thing? by the time i could afford it, the timing chain broke and bent a
valve (scrap metal now, IIR). still got the new sprocket kicking around someplace, along with a new
tach cable.
--
~Travis

http://www.megalink.net/~farmers/
 
"Kent" <[email protected]> wrote in message news:[email protected]...
>
> "Cameron" <[email protected]> wrote in message
> news:[email protected]...
> >
> > "Dave M Wyman" <[email protected]> wrote in message
> news:u78Ha.212160$M01.95035@sccrnsc02...
> > > Help! I put a new chain on my bike, along with a new cassette. It's a SCRAM chain designed for
> > > bike with nine cogs, like mine, and is the same kind of chain I had on before.
> > >
> > > The chain skips (well, it drops down a cog- the the third largest to the fourth - and then
> > > back up). It does this when I'm in the middle chainring and when I'm applying power up a steep
> > > hill.
> > >
> > > It doesn't seem to skip in the big chainring or the smallest. Just the
> > > middle. I've tried three cassettes, now - the new one, one that never had much use, and my old
> > > one.
> > >
> > > Any idea on what could be causing this? Could it be the middle chainring? Or is the chain a
> > > more likely culprit? (Rhetorical question: How much more money do I have to spend?!?)
> > >
> >
> > Dave S. may also be correct, but it sounds like your rear cable tension
> isn't
> > quite right. Try adding tension to the cable at the derailleur 1/8 turn
> (at most)
> > at a time. Usually when the chain moves back and forth the cause is that
> the
> > cable has too much slack, so it can't offset the springs in the
> derailleur. Too
> > much tension and it will jump cogs.
> >
> > Count your turns and remember them, just in case you need to reset the
> tension.
> > Happy fiddling.
> >
> Another possibility is the alignment or the rear hanger to the wheel. Get to the LBS and have them
> screw a tool into the thread for the rear mech and then the hanger can be adjusted so it is
> parallel to the rear wheel, top bottom and directly rear. It is surprising just how many rear
> hangers are out. My LBS that is closing in 2 weeks used to check all new bikes and found many out,
> some quite bad. I have a Scott GZero Strike mine was ok. I had a nasty crash and my rear gear
> started this. I changed the cable and it was about 90% right then had the hanger aligned and so
> far OK. Worth a try and only takes 5 mins. One nasty incident I have had was the rear cassette
> coming loose, check the nut! Clean the thread and locktight it.
>
> Kent

Whoa! Great point. I forgot about the time when my bike wouldn't stay in gear. Turned out that the
bracket that holds the B-screw on the derailleur cracked, so the B-screw slipped off the hanger. XT,
BTW. Keep an eye on that....

--
Cameron
 
On Tue, 17 Jun 2003 00:16:50 GMT, "Cameron" <[email protected]> wrote:

>"Bill Wheeler" <[email protected]> wrote in message
>news:[email protected]...
>> On Mon, 16 Jun 2003 00:24:58 GMT, Dave M Wyman <[email protected]> wrote:
>>
>> [snip ****]
>>
>> Should have got an SS. :p
>>
>> Peace, Bill
>
>Dang, I disappear for awhile and come back to see that you are just as anal as I remember. ;-)

The more thing change the more they stay the same......whatever the fvck that means.

Peace, Bill The mind serves properly as a window glass rather than as a reflector, that is, the mind
should give an immediate view instead of an interpretation of the world.
:-]
 
"Kent" <[email protected]> schrieb im Newsbeitrag
news:[email protected]...

> Another possibility is the alignment or the rear hanger to the wheel. Get
to
> the LBS and have them screw a tool into the thread for the rear mech and then the hanger can be
> adjusted so it is parallel to the rear wheel, top bottom and directly rear. It is surprising just
> how many rear hangers are out. My LBS that is closing in 2 weeks used to check all new bikes and
found
> many out, some quite bad. I have a Scott GZero Strike mine was ok. I had a nasty crash and my rear
> gear started this. I changed the cable and it was about 90% right then had the hanger aligned and
> so far OK. Worth a try and only takes 5 mins. One nasty incident I have had was the rear cassette
> coming loose, check
the
> nut! Clean the thread and locktight it.
>

Both Cameron and Kent have good points. Actually from what kent mentions, it may be wise to invest
in that tool for aligning the drlr. Then you don't need to go to the shop anymore when it goes out
of alignment.

-Dave
 
"Bill Wheeler" <[email protected]> wrote in message
news:[email protected]...
> On Tue, 17 Jun 2003 00:16:50 GMT, "Cameron" <[email protected]> wrote:
>
> >"Bill Wheeler" <[email protected]> wrote in message
> >news:[email protected]...
> >> On Mon, 16 Jun 2003 00:24:58 GMT, Dave M Wyman <[email protected]> wrote:
> >>
> >> [snip ****]
> >>
> >> Should have got an SS. :p
> >>
> >> Peace, Bill
> >
> >Dang, I disappear for awhile and come back to see that you are just as anal as I remember. ;-)
>
> The more thing change the more they stay the same......whatever the fvck that means.
>
> Peace, Bill

"Thing" refers to one; "they" refers to multiple people. Just how many single "imaginary friends" do
you have?????

--
Cameron
 
Thanks to all for the various suggestions - although none of them solved the problem!

My LBS mechanic did use the tool that can straighten a bent drlr hanger, as per one suggestion - I
think I'd like to get that tool. When the mechanic finished, and I got the chain to skip again, we
both realized all that was reasonably left to check was the middle chainring, and in fact that was
the problem - it had worn out from one climb too many.

Again, thanks,

Dave
 
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