Campy10 Record shifts by itself when out of saddle climb/accerate

[munch18]

My Record 10 will shift down 1 cog (13 to 14; 14 to 15; and 15 to 16 most problematic gears) when I stand and climb or accelerate with alot of torque on the cranks. Under normal riding I have a good compromise between up and down shifting, no problems. Cogs do not look worn at all (11-23 ti). Cable tension is good and cable is lubed. I'm at a loss here. I don't know if it's the right ergo shifter or not. Reading the Campy Only section of when to rebuild the shifter doesn't seem to indicate a problem here. But, a right shifter rebuild is alot cheaper then replacing the cogset. Anyone with any ideas or had this problem? Thanks

 

[daveornee]

Originally posted by munch18
My Record 10 will shift down 1 cog (13 to 14; 14 to 15; and 15 to 16 most problematic gears) when I stand and climb or accelerate with alot of torque on the cranks. Under normal riding I have a good compromise between up and down shifting, no problems. Cogs do not look worn at all (11-23 ti). Cable tension is good and cable is lubed. I'm at a loss here. I don't know if it's the right ergo shifter or not. Reading the Campy Only section of when to rebuild the shifter doesn't seem to indicate a problem here. But, a right shifter rebuild is alot cheaper then replacing the cogset. Anyone with any ideas or had this problem? Thanks

Check out the article on Sheldon Brown's site:

<http://sheldonbrown.com/derailer-adjustment.html>

and click the link "Autoshifting" which will scroll you down in the article to something you may have missed.
"If the bottom-bracket cable guide has too much friction, it can act as a one-way clutch, pulling the cable down from the lever, but not allowing it to retract on the opposite pedal stroke. In many cases, greasing the cable guide is all that is required."

Ooops I guess he moved that part to a new separate article...:

<http://sheldonbrown.com/autoshift.html>

 

[gclariosa]

I suggest you first loosen your derailleur cable and check the line of the derailleur pulley with respect to the last cog. If you have the campy installation manual, do check its ideal line.

good luck...

 

[gclariosa]

I suggest you first loosen your derailleur cable and check the line of the derailleur pulley with respect to the last cog. If you have the campy installation manual, do check its ideal line.

good luck...

 

[JohnO]

How'd you get it to do that? Sure wish my Campy 10 would kick down a gear when I stand on it... you sure this isn't a prototype of the new automatic transmission?

But seriously - any flex in your frame or BB? The tolerances on Campy 10 are real close, I suspect that it doesn't take a lot of movement to get it to jump a gear. Might also back off the cable adjustment on the rear der. half a turn and see if that solves the problem.

My groupo is on a rather stiff carbon Trek YFoil frame. Once past the initial two week adjustment for cable stretch, I haven't touched the adjustments, and that was over a year ago that I put it together.