New KMC 8-99 Chains Skipping

[il padrone]

How have you joined the new chain? Quicklink or re-inserted rivet?

[IronMac]

Check the jockey wheels are smooth they have a habit of locking up on the tensioner.  Also we have talked about the rear sprocket what about the chain ring how does that look.

Peter

Jockey wheels look good but I would have to take the chain off in order to spin them by hand. I clean those little guys by hand since it is easier for me to get in there with a piece of towel to scrape every tooth.

Chain ring looks good too but I have nothing to compare it against. All teeth are accounted for...no one tooth seems too sharp or too short.

[IronMac]

How have you joined the new chain? Quicklink or re-inserted rivet?

All chains done with quicklinks or whatever KMC calls them...Masterlinks?

At the side of the road, in addition to thinking it was a tight link I also looked for any pins that might be protruding. I saw one that was out a couple of millimeters so I whipped out a chain tool and gently nudged it flush with the rest of the link. No effect.

[IronMac]

Doesn't appear from the photo that a worn sprocket is the problem here.

Heya! Aren't you also on Bikeforums.net or Bikeforums.com? The name is very familiar.

I'm preparing an order for sprocket replacement just in case...

[Andre Jute]

Heya! Aren't you also on Bikeforums.net or Bikeforums.com? The name is very familiar.

I was in the newsgroup RBT in the great days when Jobst Brandt, Sheldon Brown and Chalo Colina were there. Since then it has been taken over by the vehicular cyclists, the anti-helmet zealots, and mindless political spammers, so I generally give it a miss and instead make my cycling home here. Perhaps you saw my bicycle pages on my netsite http://coolmainpress.com/BICYCLING.html or perhaps you just saw my books or my journalism.

[John Saxby]

make my cycling home here

  For which, Andre, we're thankful.    :-)

[JimK]

I hope you don't mind me mentioning, Andre, another of your realms:

http://www.goodreads.com/group/show/46791-robust

[IronMac]

Hrmm...I don't know about newsgroups since when I was on there in the early '90s I was not in any bicycling ones. But Andre Jutes is very familiar for some reason...


Anyways, back on topic...could it be the chains themselves?

[Andre Jute]

  For which, Andre, we're thankful.    :-)

You're so gracious, John. It's great to be with agreeable, knowledgable people.

I didn't know you visited ROBUST, Jim. You should contribute. Everyone who's interested is welcome. https://www.goodreads.com/group/show/46791-robust

Mac, if you were into tube audio and high efficiency loudspeakers in the 90s, you'll know me. http://www.audio-talk.co.uk/fiultra/JUTE%20ON%20AMPS.htm

About your chain, it's most unlikely that both your chains should be faulty. If the teeth on the chainwheel are good, if the chain line is straight enough, if the chain has no stiff links, then all that is left is the tensioner, and if it worked before, then you must have disturbed something when you fitted the new chain. Were my bike, I'd count the links very carefully; it is easy to measure two chains of equal length and then to fit the new one with a quick link from the packet without noticing that it is in fact an extra link.

[IronMac]

Were my bike, I'd count the links very carefully; it is easy to measure two chains of equal length and then to fit the new one with a quick link from the packet without noticing that it is in fact an extra link.

Bingo!!!

That is not exactly what happened but I was desperate enough to decide to take off the old chain and lay it side by side with one of the new 8-99s to see if there was an extra link or MissingLink.

It was immediately apparent that the new chain is much LONGER than the old one. Bike Friday had snipped off 10 links off of the old Z-50!!!

This may explain why the KMC European site says that their high-end IGH chains have 110 links...guess you could always snip off a couple to make it fit.

So, before I go and snip off ten links...any objections or gotchas? Thanks!

[JimK]

I always remove a bunch of links from a new chain to get it to fit my Nomad correctly. Ought to be a routine operation.

[phopwood]

Measure twice cut once, is my only advice.

Peter

[IronMac]

Measured and counted three times!

Well, some joy. The skipping has really cut down but in a very short 5 min ride (it's pouring outside right now) it skipped about 9-12 times. And it did not skip in all gears as it did before. And it seemed to skip in certain parts of the cadence or revolution.

[phopwood]

Sounds like you are nearly there.

Do you now have the same amount of links as the old chain, if you do I would look at the tensioner spring.  Can you take a picture of the whole drive including Tensioner, rear and front sprockets.

Peter

[il padrone]

12" of chain on your new chains will be 24 links. Have you measured those 24 links on your old chain? Was it under 12 1/8", or more than this?