Chain Skip -Record 10
 

Hi,
I just completed a full overhaul and I find my chain skipping in middle gears. Overhaul included new cables, new housings, new chain, a lever overhaul (new G springs, return spring & coil spring), bottom bracket overhaul and hub overhaul. My LBS did the levers for me. I don't have bar tape on, yet. Housing is secured to bars with electrical tape (in several locations). I used old housing and old chain to determine correct lenghts. FYI I replaced my rear cassette last year with a new chain so I don't think the cassette is worn.

I followed Campy rear derailluer instructions to set limit screws and cable tension. I repeated this procedure several times after noticing the skip problerm. Cable tension feels good to me (not loose or super tight).

Before lever overhaul, I had shifting problems. It would miss shifts and I'd have to feather the lever a bit to complete some shifts. I didn't have a skipping problem.

I think this points to a lever problem, but I'm not sure. I'd appreciate any troubleshooting help.

Thanks,
SEA

It usually results from replacing the chain without replacing the cassette. If the cassette is worn enough it will cause what you experience. The solution is to replace the cassette, if this is the case.

My current cassette has only seen one season's use (approx. 3500 mi). My chain was replaced at season start and mid season. Shouldn't the cassette last longer? I ride in dry conditions and keep things ship shape. Can I confirm cassette wear with a visual inspection. I have access to a microscope. If so, what should I look for?

OK this might be way off track, but I had another thought. I did remove my cassette for cleaning during hub overhaul. What if I got the cassette lock ring too tight? Could this cause problems?


SEA

Are you sure the cable tension is right? New cables stretch a little during a breaking in period. Check the alignment of the rear der. below the cogs. I bet it will be ever so slightly off.

I did recheck cable tension several times. The rear derailler is slightly misaligned in the skipping gears; however, if I adjust it for good alignment, it seems like the skip problem migrates to other gears.

I would re-setup the rear der. as per either the park tools how to or the one on Sheldon Brown's page. Start from the beginning and don't skip any steps. Do it like a new installation.

As a last resort i would buy a new cassette (those things are expensive)

OK. I found Sheldon's site, but I can't seem to locate instructions from Park Tools. Can you point me in the right direction?

I once had a skipping problem that seemed to be caused by insufficient torque when tightning the cassette. This happened on an Ultegra-9. Re-torquing fixed it. Hope that this helps....

On the Record 10 speed UD cassette, be sure you put the correct spacer between the correct cogs. Those spacers between the bigger cogs are different sizes.

I have a similar problem on a bike that has max 1000 miles on the cassette and chain.

Tim

That's another interesting thought. I used the Record 10 cassette manual, and I thought I was careful about the spacers, but it's definately worth a double check.

FYI
Thank you ALL for responding. :)

Good read.

It says, "The goal of adjusting the indexing is to find the tightest inner wire tension setting that will allow good shifting to the gears normally used."

Park advises to take out slack in smallest rear gog and largest front chain ring. The Campy manual directs me to use the small front chain ring. Seems like Park's approach might take out a bit more slack?

Now that someone said it, I would check that spacer/cassette thing. That could do it.

I had great luck with the Park Tool method. I ride Shimano, though.

Good luck and let us know when you have it worked out.

Yes, I would think your cassette should last longer as long as you don't engage in cross chaining and keep things clean and lubricated. But you never know. It is not so much the wear on the cassette as the difference in wear between cassette and chain. You can leave an old chain and old cassette together for a very long time without the skipping. My suggestion would be to put the old chain back on and try it. If it clears up the problem then you will know.

If you can see the wear on a cassette, then it is pretty far gone and should be replaced regardless of chain skipping. I don't think you would see the wear on a cassette as young as yours. The only way to know for sure is to reinstall the old chain.

Good idea, but it's somewhat complicated to pull off. Campy chains come production stamped outer link that mates with the accompanying rivet. To re-install my old chain, I'll have to purchase a special set of links that have two production stamped outer links on opposite ends and two rivets.

I suppose I could try to re-install it the old fashioned way. I think I might end up with stiff links if I can get it together at all.

I did a little more troubleshooting last night. Below, I've outlined my efforts.


Problem Description:
Upon this morning's reflection, I realize that I don't have a good problems description. The derailluer is overshifting and completely skipping a cog as I shift to lower gears. This happens somewhere around gear 4-6. I think I still need to define the problem better.

Cassette Spacers:
I had the spacers installed correctly. There are a total of five spacers. For the 12-25 cassette, three outboard (high gear) spacers are the same thickness while two inboard spacers (low gear) are different. Just for grins I swapped the two inboard spacers. It's plainly obvious when these two spacers are reversed. Cogs 4 & 5 are clearly too close together.

Cassette Wear:
I haven't completely eliminated this possibility as I didn't re-install my old chain. I did measure for stretch using my Park tool. There are no measurable differences between new and old chain. Is it true that cable stretch is the primary cause of cassette wear?

Cassette lockring:
I found it was a little loose, but tightening had no affect.


Cable Tension:
I tried both Campy's procedure and the Park Tools procedure closely. I do not believe cable tension is a problem.

Cable Routing:
I know that the cable moves smoothly through the housing. I pushed it out of the shifter's cable anchor and moved the cable back and forth. The cable moves very smoothly. In fact, I routed the cable housing through the shifter's inboard slot because the cable moves more smoothly as aposed to the outboard slot.

Housing/Cable:
I'm not using Campy cables and housing. I bought Le Tour cables and housing from Branford Bike. Upon inspection, the housing looks comparable, but the cable is different. Looks like Campy uses finer wire in their cable.

Shifter:
It's interesting that I haven't had anyone suggest my shifter might be causing problems (other than myself). I'm not sure how to eliminate this as a possibility. My shifter was just overhauled by my LBS. I know the staff rides Campy but sells Shimano so I don't know how much experience they have overhauling shifters.

Derailleur Hanger/Frame alignment:
Before starting my overhaul, I had my LBS check both of these.

Thanks again for all the help.

SEA

We have a winner thanks to my LBS (they diagnosed the problem within 3min of my arrival).

Cable routing was my problem. I routed the cable on the wrong side of the anchor bolt, so it was slightly offline. I flipped the anchor plate 180 when I cleaned up the rear derailleur. The anchor plate has a cable groove so I routed to the cable groove side without questioning the anchor plate installation. :o

Live and learn.

Thanks again.

SEA

Good on ya! Glad it turned out well.