Monday, May 4, 2009

Problem Solved...The Shimano 7900 chain issue

I got the new Shimano Dura Ace 7900 chain back in late February. This is the directional chain in which the engraved side needs to face out.

It comes with a Quicklink which you could use to connect it. The Quicklink is also directional and goes on like this:
And should look like this when on the bike:

Everything seemed to work fine. Then on a rainy Saturday morning my bike got dirty. I went home and cleaned it immediately like I usually do. The next day I had a clicking type of feel in my cranks (at least that is where it seemed like it was coming from). I took the cranks off and inspected them...they were fine. I replaced the cassette, tried a different rear wheel, and even swapped pedals. No fix. This mainly occurred when I was in my 21, 19, 17... basically at the top of the cassette whether or not I was in the small or big ring.

I finally put the chain from my TT bike on and it fixed the problem. So now I was a little pissed. I just spent a bunch of money on this chain that lasted me for less then a month. I inspected it numerous times. I verified 50 times it seems that the chain was installed correctly. It would not skip at all on the work stand and only seemed to skip or click in those low gears.

I finally realized it definetely had a feel like a stiff link. But non of the links were stiff. So I finally took the Quicklink off and replaced it with the old fashion Shimano replacement pins that is still an option with this chain.

Problem solved. That quicklink must have gotten some dirt or grime in it and because of how precise it is, messed it up.

Anyone else have any problems. I couldn't find any information on this during this time of annoyance for me. So I thought it would be a good idea to post it this issue so someone else doesn't end up pulling their hair out.

7 comments:

Tim Oborn said...

I too have just installed the 7900 chain with quick link. However I was a chain virgin... first do it myself. So I was very careful and read the instructions heaps of times and tripled checked everything. Seems weird to leave out two rollers but local bike shop said this was correct. First ride I also got clunking in the pedals. Definitely the quick link I reckon.

Unknown said...

The 7900 chain is a piece of junk. Like many things in the bike industry, this chain went the way of losing a few grams (by slotting the inner and outer plates) and sacrificing durability. After a couple months, my chain twisted (the inner link). I practice sprinting twice a week and this chain cannot hold-up to it. The perfect chain is the 7801 with a Wippermann link.

chris said...

It is absolutely the quick link that is the problem addressed in the post. I went through the same trial with my brand new DA chain. Lots of popping/clunking sounds. My LBS identified that it must have been the quick link. They replaced and the clicking was gone! However,after the first 200 miles the popping started back up again. To assure myself that is was the quick link I went back to the LBS to get another quick link. They didn't have one. Then I called three more LBSs and none of them had them. The last one I contacted said the Shimano rep advised them (and anyone else with the same problem) to avoid replacing the link and just put in the old pins. How annoying, but it's a new thing and we have to expect that there will be bugs to fix and that's the risk you take when buying a new product. I'm now wondering if you could use the SRAMs powerlink on the DA chain. Any thoughts?

Anonymous said...

Great post. I am having the exact same problem. I have taken my bike to 3 mechanics. I can hardly describe the problem. I have replaced everything on the drivetrain in an effort to get rid of the issue. I will go to back to the regular link.

Paul said...

I've been going crazy with the same problem! Thanks for posting. I'm going to change it out as soon as I can get a new link.

Unknown said...

Just wondering if this theory would hold true for the Ultegra 6700 chain as well? I recently put a 6700 chain on my bike after having some trouble with the stock KMC chain that it came with. When I bought the 6700 chain, the LBS also sold me a generic "super-link". I say "generic", because it is not a SRAM Powerlink, nor a Wipperman Connex, nor a Shimano Quick-Link. It is called a "Super-Link" and the package says that it is compatible with DA 7800 and Ultegra 6600...but it doesn't list 7900 or 6700. This has me wondering, because I am getting the same popping, clunking noises that everyone else here has described. The only difference in my case, is that my link seems to get caught up in the guide pulley and not on the cassette itself. Could it be that these newer Shimano chains are just not meant to be run with any of these easy removable links?

fire fitness and bikes said...

I would suggest ditching the quick link. For road bikes, which typically don't have chain problems in which fixing on the road is common, I would just stick with the hard connection methods.