Sluggish shifting onto smallest cog

[Eric Goforth]

Hi,

I have a 8-speed Campy Ergopower shifting with a Mirage rear derailleur. The shifting is sluggish onto the smallest (12T) cog. Everywhere else it's fine. The cables are new, and feel good. I reduced my cable tensions such that I have a lot of slack, the shifting was still sluggish when I pushed the derailleur up by hand and let it return under spring tension only. I unscrewed my high limit screw totally from the derailleur, but it didn't help. The derailleur doesn't seem to be binding that I can feel. The derailleur hanger looks straight although it was bent and I bent it back. Any suggestions of what to look for?

-Eric

[davet]

Take it to a shop to have the derailleur hanger checked for proper alignment. Eyeballing it isn't really good enough.

[Frank Krygowski]

That's happened to me occasionally with several different derailleurs.
In my experience, it's been a friction problem. I've fixed it every
time by lubricating/cleaning cables and guides (especially where they
pass under the bottom bracket) and lubricating derailleur pivots and
springs.

- Frank Krygowski

[John B.]

You need to check alignment of the hanger vertically as well as
horizontally with either an alignment "gage" or by using a straight
edge as the hanger is too narrow to actually tell with any accuracy
whether it is bent or not.

When you say "sluggish" do you mean that it takes a larger portion of
a revolution of the cassette for the chain to complete the jump from
cog to cog? Or a longer period for the chain to "catch" on the next
cog after you move the shifter?
--
Cheers,
John B.

[datakoll]

tighten cable to shift down ?

yup first redo all friction poitns, cable, deray hinges, clean and lube.

Over in the wax lube post, I mention CRC HD Silicon spray...the friction points sprayed with CRC give a first indication of fixing it thru clean and lube.spray and workmit around 'like' lift cables and deray to extend surfaces, spray and release...pullback and forth.

lube cable entry into deray....all tighter cable turns and wear points...exits and entries

Have you used a string ? string the drive line front to bacl so you can relate parallels in drive train to the string's straightness.

try UTUBE and Park Tool for deray adjustments.

[Stephen Bauman]

+1

The original poster states that the cable is slack and the high limit
screw is OK. I assume he means that the bare inner cable is slack on the
downtube between the two cable stops. If so, there is something
preventing the derailleur from moving outward and that something is
between the slack cable on the downtube and the derailleur.

Next follow that bare cable to the chainstay. If it not slack on the
chainstay but slack on the downtube, then there is friction where the
bare cable passes under the bottom bracket. That should be easy to fix
because it's out in the open for anyone to see.

If bare cable is slack at the chainstaty and the downtube, then the
problem is after the rear cable stop: the covered cable and/or the
derailleur. Pull the cable from the derailleur and actuate the derailleur
by hand. Push on the derailleur body to shift to a lower gear and then
slowly release the pressure on the derailleur body.

If the derailleur does not shift crisply into the smallest cog, then the
problem is in the derailleur body. It could be either the cage and chain
do not have adequate clearance at a cog (B-screw, unlikely), the
parallelogram pivots need lubrication or there's something interfering
with the spring (trapped road debris).

If the derailleur does shift crisply into the smallest cog, then the
problem is friction within in the covered cable leading to the
derailleur. That friction could be debris within the cable, frayed inner
cable (unlikely because OP replaced the inner cable), internal frayed
cable in the compressionless outer sheath, sharp kink in the outer sheath
(look at the end caps) or misaligned end caps (look for signs that inner
cable is not centered in the end cap but rubs against it - more likely at
derailleur side).

Good luck.

[cycl...@hotmail.com]

Eric,
If you have

If you have not solved your problem yet, here are a couple more tips to try.
Has the cable <housing> been replaced with new also. Sometimes gunck will collect in the housing especially around the ends near the RD. Replacing both cable and housing is the answer to better shifting when old needs replaced. Try not to short change yourself by cutting the housing too short at the RD. Check the housing along its route from the shifter to the RD, it may be binding somewhere.
Double check the hanger alignment.
If all else fails, start from scratch at adjusting the rear shifting. Trying to work your way out of a problem in the middle sometimes gets you no-where.
Cheers,
Coz

[Frank Krygowski]

On Oct 9, 9:42 am, Stephen Bauman <sbau...@abt.net> wrote:
>
> If the derailleur does not shift crisply into the smallest cog, then the
> problem is in the derailleur body. It could be either the cage and chain
> do not have adequate clearance at a cog (B-screw, unlikely),  the
> parallelogram pivots need lubrication or there's something interfering
> with the spring (trapped road debris).

Speaking of that spring: There are different designs for the internal
springs. I don't know what Campy uses, but it seems like most of the
Shimano derailleurs I've seen use a coil tension spring.

OTOH, my old SunTour derailleurs use a torsion spring ending in an arm
that rests on an internal surface of the derailleur parallelogram.
That interface forms a sliding contact that needs lubrication and
cleaning once in a while. It's given me the exact symptom described
by the OP.

- Frank Krygowski

[AMuzi]

Could well be just dried lubricant and crud in the changer's
pivots. We like Rock & Roll for that sort of thing. If it's
visibly grungy, try an alcohol/compressed air clean first.
Lubricate with R&R copiously, work the changer back and
forth until free and wipe up excess after.

--
Andrew Muzi
<www.yellowjersey.org/>
Open every day since 1 April, 1971

[datakoll]

why are Campy owners having such a good time ?

We like Rock and Roll BECASUE...

to which KING OF LUBES product is nA.Muzi refering ? Nipple Cream ?

Yo Rita....


I did a cable thing with the van mounted Redline...rear brakes..

^*YHHG^&& wood nut disengage so HOTTD, sprayed witg CRC Silicone pushed and pulled then went on with brake dragging...then my eyes readjusted to working on the mechanism n I saw a slight cable bend back in the pipe...woked the bend and wooolaaaahhhhh release !!!!

Now I cudda goine thru the ENTIRE ROUTINE but I said fuck it and .....

My ACTRON multimeter stored in a Wal Blue Clasp Box turned itself on with a tight lid and mating cables...lost two Wals this way. one whining into death IN THE BACK whilst crossing Wyoming..

So I scrwed up a continuoty tester...the peizo burning out on the ACtron..so I'm standing at the 'bench' with the new tester and I invoke Murphy's Third lw
saying to the Actron..."gge whiz I wish you still worked'

n I tried the Actron continuity again and fucking A Dude it came back on.

[AMuzi]

It's not on my top ten, or even twenty, list for chain
lubrication but Rock & Roll is phenomenally effective at
penetrating stuck things such as derailleur pivots.

http://rocklube.com/

[datakoll]

possible worm hole...

https://www.google.com/webhp?hl=en&tab=gw&q=Search%20for%20topics#hl=en&sa=X&psj=1&ei=ecx0UOrXDpDU8wS5t4HADg&spell=1&q=rock+n+roll+penetrating+oil&ved=0CBsQBSgA&bav=on.2,or.r_gc.r_pw.r_qf.&fp=a2813cd146f0d219&biw=1152&bih=614

[Eric Goforth]

I haven't yet tested my bike on the road, but I tweaked the alignment of my dropout and it fixed the problem on my bike stand. The problem was that my rear derailleur would shift quickly down to my 13, but would grind away for probably a full revolution of the crank before finally dropping the the 12 (my smallest cog). Under load it wouldn't really shift into the 12 at all, but would just grind and grind.

I improvised a dropout alignment tool that seems to work well enough. I bought a fairly long 10mm x 1mm pitch bolt at my local (pretty well stocked) hardware store. I then threaded the bolt into my dropout and used a jam nut to hold it against the derailleur hanger. I was going to try to drill a hole in a piece of wood to use as my "pointer", but then I noticed my old Minoura wheel dishing too. I took out the center piece, the part that fits against the axle locknuts, and it fit over my 10 mm bolt reasonably snugly, even more so with another jam nut tighted down against it and with some washers to get everything spaced appropriately.

So I was able to use my wheel dishing tool and it showed me I had a noticably bigger gap at the top than at the bottom, probably 3/4" at the top and zero at the bottom. Too make sure my wheel dishing tool wasn't tweaked, I took the alignment tool apart and flipped over the wheel dishing tool and the gap stayed the same. I also checked it front and rear and it seemed good that way. I used a 17 mm wrench as a lever on the 10 mm bolt to bend the dropout. The shifting, at least on my workstand, seems very good now.

Minoura apparently doesn't make this tool any longer, it has kind of a tubular pieced in the middle that fits over the axle and against the locknuts. I bought mine 25 years ago.

-Eric

[John Thompson]

On 2012-10-09, AMuzi <a...@yellowjersey.org> wrote:

> On 10/8/2012 10:52 PM, Eric Goforth wrote:
>>
>> I have a 8-speed Campy Ergopower shifting with a Mirage rear derailleur. The shifting is sluggish onto the smallest (12T) cog. Everywhere else it's fine. The cables are new, and feel good. I reduced my cable tensions such that I have a lot of slack, the shifting was still sluggish when I pushed the derailleur up by hand and let it return under spring tension only. I unscrewed my high limit screw totally from the derailleur, but it didn't help. The derailleur doesn't seem to be binding that I can feel. The derailleur hanger looks straight although it was bent and I bent it back. Any suggestions of what to look for?

> Could well be just dried lubricant and crud in the changer's
> pivots. We like Rock & Roll for that sort of thing. If it's
> visibly grungy, try an alcohol/compressed air clean first.
> Lubricate with R&R copiously, work the changer back and
> forth until free and wipe up excess after.

I have a Huret Jubilee that does this. I've been attributing it to
old age.

--

-John (jo...@os2.dhs.org)