Chain Skips Over Middle Ring Problem



B

buck

Guest
I suppose this is an easy problem to solve if you know what to do.

On my road/cross bike, when I shift from the large chain ring to the middle
ring the chain will usually skip right over the middle ring to the small
chain ring. I've tried to fast shift as well as slow shift and it makes no
difference. It will skip over the middle ring probably 8 out of 10 times.
There is no problem shifting from the small ring to the middle ring. Along
with this I am getting a lot of chain rub on the front derailleur when in
the middle ring.... almost no matter where the rear position is. This is a
new bike with less than a few hundred miles on it. I am guessing I will
have to adjust the front derailleur or bend it but I would rather hear from
the experts first........

-Any help appreciated.
 
>On my road/cross bike, when I shift from the large chain ring to the middle
>ring the chain will usually skip right over the middle ring to the small
>chain ring. I've tried to fast shift as well as slow shift and it makes
>no
>difference. It will skip over the middle ring probably 8 out of 10 times.
>There is no problem shifting from the small ring to the middle ring. Along
>with this I am getting a lot of chain rub on the front derailleur when in
>the middle ring.... almost no matter where the rear position is. This is
>a
>new bike with less than a few hundred miles on it. I am guessing I will
>have to adjust the front derailleur or bend it but I would rather hear from
>the experts first........
>
>-Any help appreciated.


Make sure the outer plate of the cage is parallel to the outer chainring.
Phil Brown
 
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In article <[email protected]>,
buck <[email protected]> wrote:
>I suppose this is an easy problem to solve if you know what to do.
>
>On my road/cross bike, when I shift from the large chain ring to the middle
>ring the chain will usually skip right over the middle ring to the small
>chain ring. I've tried to fast shift as well as slow shift and it makes no
>difference. It will skip over the middle ring probably 8 out of 10 times.
>There is no problem shifting from the small ring to the middle ring. Along
>with this I am getting a lot of chain rub on the front derailleur when in
>the middle ring.... almost no matter where the rear position is. This is a
>new bike with less than a few hundred miles on it. I am guessing I will
>have to adjust the front derailleur or bend it but I would rather hear from
>the experts first........
>



_ How big is the sprocket in the back when you are attempting
this shift? If it's on the large size(32-30) the shifting pins on
the middle chainring will make it impossible to ride
middle/large. Before you go too far though you should check the
basics

1. Chainline

2. Derailer alignment

_ You can find out about both at Sheldon Brown's useful website.

http://www.sheldonbrown.com/gloss_ca-m.html

http://www.sheldonbrown.com/derailer-adjustment.html#front

_ Booker C. Bense

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buck wrote in message ...
>I suppose this is an easy problem to solve if you know what to do.
>
>On my road/cross bike, when I shift from the large chain ring to the middle
>ring the chain will usually skip right over the middle ring to the small
>chain ring. I've tried to fast shift as well as slow shift and it makes no
>difference. It will skip over the middle ring probably 8 out of 10 times.
>There is no problem shifting from the small ring to the middle ring. Along
>with this I am getting a lot of chain rub on the front derailleur when in
>the middle ring.... almost no matter where the rear position is. This is a
>new bike with less than a few hundred miles on it. I am guessing I will
>have to adjust the front derailleur or bend it but I would rather hear from
>the experts first........
>
>-Any help appreciated.


move the mech. down so that the outer plate clears the big ring by 2mm. As
long as it does not stick when moving from the big, that should sort it.

Trevor
 
On Thu, 12 Aug 2004 12:26:07 -0600, "buck" <[email protected]>
wrote:

>I suppose this is an easy problem to solve if you know what to do.
>
>On my road/cross bike, when I shift from the large chain ring to the middle
>ring the chain will usually skip right over the middle ring to the small
>chain ring. I've tried to fast shift as well as slow shift and it makes no
>difference. It will skip over the middle ring probably 8 out of 10 times.
>There is no problem shifting from the small ring to the middle ring. Along
>with this I am getting a lot of chain rub on the front derailleur when in
>the middle ring.... almost no matter where the rear position is. This is a
>new bike with less than a few hundred miles on it. I am guessing I will
>have to adjust the front derailleur or bend it but I would rather hear from
>the experts first........
>
>-Any help appreciated.


It's possible the cable has simply loosened a bit. This would permit
the derailleur to ride inboard when the lever has it in the middle
position. The chain would almost always rub, and shifting from the big
ring would almost always shift past the middle ring.

See Sheldon Brown's derailleur adjustment article, and pay attention
to comments about tuning the cable tension for the middle position.

Or since you mention it's pretty new, maybe the dealer will tune it up
as part of the break-in tune-up (often free).
 
On Thu, 12 Aug 2004 12:26:07 -0600, "buck" <[email protected]>
wrote:

>I suppose this is an easy problem to solve if you know what to do.
>
>On my road/cross bike, when I shift from the large chain ring to the middle
>ring the chain will usually skip right over the middle ring to the small
>chain ring. I've tried to fast shift as well as slow shift and it makes no
>difference. It will skip over the middle ring probably 8 out of 10 times.
>There is no problem shifting from the small ring to the middle ring. Along
>with this I am getting a lot of chain rub on the front derailleur when in
>the middle ring.... almost no matter where the rear position is. This is a
>new bike with less than a few hundred miles on it. I am guessing I will
>have to adjust the front derailleur or bend it but I would rather hear from
>the experts first........
>
>-Any help appreciated.
>
>


Hi, best thing would be stop by your dealer, it is new. But, two other
possibilties are that the cable needs to be tightened. There should be
an inline adjuster, most likely at the downtube bosses [the place
where down tube shifters would be mounted, if the bike had them] ,
while on the bike, turn the barrel a half to whole turn, counter
clockwise. The other possibility is that that outer limiting screw,
needs to be adjusted, so that the derailleur will move further
outward.
I had the same problem after replacing my crankset, the bike would
shift fine, while stationary, in a trainer. But when riding it would
skip the middle ring, tightening the cable would help, although it
would usually malfunction, soon after. Adjusting the derailleur
outward, solved the problem. See, when I would shift, the cage would
travel the set distance and the fact that the cage was just barely
over the large ring, it would go past the middle one.
This happened, after I had followed the specs and adjusted the cage,
just about 1 mm of clearance to the right, when on the big ring.
After I made that adjustment, it has never missed the middle ring.

Life is Good!
Jeff
 
nottoday-<< On my road/cross bike, when I shift from the large chain ring to
the middle
ring the chain will usually skip right over the middle ring to the small
chain ring. >><BR><BR>
<< This is a
new bike with less than a few hundred miles on it. >><BR><BR>

Go to the bike shop where ya bought it and insist that somebody that knows
front ders adjust it!!

Not just some dolt that builds the thing.

Peter Chisholm
Vecchio's Bicicletteria
1833 Pearl St.
Boulder, CO, 80302
(303)440-3535
http://www.vecchios.com
"Ruote convenzionali costruite eccezionalmente bene"
 
Well seeing that I got it even more balled up I took some advice given here
and took it to the shop where I bought it. The tech worked on it for about
10 minutes and when all done said.... No Charge! So I tipped the guy $10
and went riding into the hills. Maybe the easy way is sometimes the best
way.
Thanks to All who have offered excellent advice.




"buck" <[email protected]> wrote in message
news:[email protected]...
> I suppose this is an easy problem to solve if you know what to do.
>
> On my road/cross bike, when I shift from the large chain ring to the

middle
> ring the chain will usually skip right over the middle ring to the small
> chain ring. I've tried to fast shift as well as slow shift and it makes

no
> difference. It will skip over the middle ring probably 8 out of 10 times.
> There is no problem shifting from the small ring to the middle ring.

Along
> with this I am getting a lot of chain rub on the front derailleur when in
> the middle ring.... almost no matter where the rear position is. This is

a
> new bike with less than a few hundred miles on it. I am guessing I will
> have to adjust the front derailleur or bend it but I would rather hear

from
> the experts first........
>
> -Any help appreciated.
>
>
>
 
Buck-<< Well seeing that I got it even more balled up I took some advice given
here
and took it to the shop where I bought it. The tech worked on it for about
10 minutes and when all done said.... No Charge! So I tipped the guy $10
and went riding into the hills. Maybe the easy way is sometimes the best
way. >><BR><BR>

Well, I would hope you wouldn't be charged!!

Next time get the gent a 6-er of his favorite brew. A bike shop w/o beer in the
fridge should be avoided.....

Peter Chisholm
Vecchio's Bicicletteria
1833 Pearl St.
Boulder, CO, 80302
(303)440-3535
http://www.vecchios.com
"Ruote convenzionali costruite eccezionalmente bene"
 
>Well, I would hope you wouldn't be charged!!
>
>Next time get the gent a 6-er of his favorite brew. A bike shop w/o beer
>in the
>fridge should be avoided.....


Oh ys, the power of the magic 6 pack. Works in many situatations.
Phil Brown