Chain skipping problem

I'm having a problem with my commuter/rain bike. Shimano 105 8spd STI shifters and rear deraileur.

The chain skips when standing up hills or sprinting, but only the middle 3-4 cogs. Same effect using
either chainring up front.

I replaced the shifter cable/housing, deraileur jockey wheels (ultegra 8 spd), and of course chain
(SRAM). I also swapped the cassette out with a much newer one from my cross bike that has virtually
no signs of wear (made no difference).

I can't seem to cure this problem by adjusting the cable tension. I'm at a loss as to why it's
skipping so bad.

I did notice the top jockey wheel I bought doesn't have much float to it, making me wonder if
ultegra 8 spd jockey wheels work with 105 8 spd deraileurs. My LBS said yes.

If anyone knows what I could try next, I'd sure appreciate it.

Thanks, Erik

 

Erik Voldengen wrote:
> I replaced the shifter cable/housing, deraileur jockey wheels (ultegra 8 spd), and of course chain
> (SRAM). I also swapped the cassette out with a much newer one from my cross bike that has
> virtually no signs of wear (made no difference).

You need a new cassette with a new chain. Put the old chain back and check what happens.

The stable situation is new cassette and old chain. If a new chain wears a little faster than the
cassette then you're okay; if it wears a little slower it will skip eventually. The best situation
is that they match but they will always mismatch because you wear different cogs differently.

Chain stretch accommodates cog hook; but chain stretch also costs you energy and wears the cogs and
chainwheels faster.
--
Ron Hardin [email protected]

On the internet, nobody knows you're a jerk.

 

"Erik Voldengen" <[email protected]> wrote in message
news:[email protected]...
> I'm having a problem with my commuter/rain bike. Shimano 105 8spd STI shifters and rear deraileur.
>
> The chain skips when standing up hills or sprinting, but only the middle 3-4 cogs. Same effect
> using either chainring up front.
>
> I replaced the shifter cable/housing, deraileur jockey wheels (ultegra 8 spd), and of course chain
> (SRAM). I also swapped the cassette out with a much newer one from my cross bike that has
> virtually no signs of wear (made no difference).
>
> I can't seem to cure this problem by adjusting the cable tension. I'm at a loss as to why it's
> skipping so bad.
>
> I did notice the top jockey wheel I bought doesn't have much float to it, making me wonder if
> ultegra 8 spd jockey wheels work with 105 8 spd deraileurs. My LBS said yes.
>
> If anyone knows what I could try next, I'd sure appreciate it.
>
> Thanks, Erik

 

Ron Hardin wrote:
> Erik Voldengen wrote:
>
>
> The stable situation is new cassette and old chain.

Bad advice! all that will do is wear the new cassette to fit the old chain!

 

I did some more fiddling. The skip isn't really a skip, but the chain trying to ride up to the
next gear. Only happens in the middle gears, and only when applying a lot of pressure, like
standing up a hill.

If I adjust the rear der. cable tension to avoid this, the lower and higher gears won't shift
correctly. Maybe my shifters are bad? No idea...Any have some good advice?

 

On 19 Apr 2003 00:54:55 -0700, [email protected] (Erik Voldengen) wrote:

>I did some more fiddling. The skip isn't really a skip, but the chain trying to ride up to the
>next gear. Only happens in the middle gears, and only when applying a lot of pressure, like
>standing up a hill.

Best cycling is done while remaining seated for a multitude of reasons. Not sure if this can be done
or not. Cycling while standing also tilts and possibly jerks the bike from one side to the other and
I've often wondered if this could cause the chain to try and grab the next gear up or down. It is
not only the chain, but possibly the rear derailleur as well that could be on the move.

Just my 2 bits.

Bert
>
>If I adjust the rear der. cable tension to avoid this, the lower and higher gears won't shift
>correctly. Maybe my shifters are bad? No idea...Any have some good advice?

 

> Best cycling is done while remaining seated for a multitude of reasons.

This is true, but if you're on a long ride, it's also important to use different muscle groups while
you relax others.

Anyway, I get ghost shifts when I've "stretched my chain" (assuming it's tuned properly). You can
get a measuring tool and see if you need a new chain. I'm sure you've already done this, but it's
also good to keep your drivetrain clean, and lube the chain.

- JD

 

> Best cycling is done while remaining seated for a multitude of reasons.

Oh PA-LEEESE. Thanks for that one, Bert

Still looking for a solution. I'm going to switch out my rear der. tomorrow. If that doesn't fix it,
it's gotta be my shifters are worn out

-Erik

 

Check out Sheldon's page on ghost shifting at http://www.sheldonbrown.com/autoshift.html

He says "The usual cause of the problem, believe it or not, is the cable guide that the derailer
cable uses to get around the bottom bracket. As you pedal the bike, the frame flexes from side to
side. This causes the gear cable to get tighter and looser with every other pedal stroke."

Try lubricating the guide. The cable might have worn a groove in the plastic. if so, then
replace it.

r.b.

[email protected] (Erik Voldengen) wrote in message
news:<[email protected]>...
> > Best cycling is done while remaining seated for a multitude of reasons.
>
> Oh PA-LEEESE. Thanks for that one, Bert
>
> Still looking for a solution. I'm going to switch out my rear der. tomorrow. If that doesn't fix
> it, it's gotta be my shifters are worn out
>
> -Erik

 

Try buying a frame that does not flex!

"rb" <[email protected]> wrote in message news:[email protected]...
> Check out Sheldon's page on ghost shifting at http://www.sheldonbrown.com/autoshift.html
>
> He says "The usual cause of the problem, believe it or not, is the cable guide that the derailer
> cable uses to get around the bottom bracket. As you pedal the bike, the frame flexes from side to
> side. This causes the gear cable to get tighter and looser with every other pedal stroke."
>
> Try lubricating the guide. The cable might have worn a groove in the plastic. if so, then
> replace it.
>
> r.b.
>
> [email protected] (Erik Voldengen) wrote in message
news:<[email protected]>...
> > > Best cycling is done while remaining seated for a multitude of reasons.
> >
> > Oh PA-LEEESE. Thanks for that one, Bert
> >
> > Still looking for a solution. I'm going to switch out my rear der. tomorrow. If that doesn't fix
> > it, it's gotta be my shifters are worn out
> >
> > -Erik

 

"Openworld" <[email protected]> wrote:

> Try buying a frame that does not flex!

Do you have any suggestions? I have never seen or ridden one.

--
Ted Bennett Portland OR