New Dura Ace chain broken

[j beede]

Never had a chain fail before... ever. My Dura Ace 10-speed chain (<150 miles) measures as new but broke yesterday under modest pressure while shifting the FD. From the looks of it the side plate was pried away from the roller and the failed link's side plate is now bent. What is my next step? Can I buy pieces of chain and reassemble it? This chain measures spot on 12" center-to-center and I would hate to throw it out--not to mention the $50-60 for a replacement!
...j

[Surly LHT]

(02-19-2010, 05:10 PM)j beede Wrote:  Never had a chain fail before... ever. My Dura Ace 10-speed chain (<150 miles) measures as new but broke yesterday under modest pressure while shifting the FD. From the looks of it the side plate was pried away from the roller and the failed link's side plate is now bent. What is my next step? Can I buy pieces of chain and reassemble it? This chain measures spot on 12" center-to-center and I would hate to throw it out--not to mention the $50-60 for a replacement!
...j

If you got it at your LBS then I would go back to them and see if they could make it good for you.

[Bill]

(02-19-2010, 05:10 PM)j beede Wrote:  Never had a chain fail before... ever. My Dura Ace 10-speed chain (<150 miles) measures as new but broke yesterday under modest pressure while shifting the FD. From the looks of it the side plate was pried away from the roller and the failed link's side plate is now bent. What is my next step? Can I buy pieces of chain and reassemble it? This chain measures spot on 12" center-to-center and I would hate to throw it out--not to mention the $50-60 for a replacement!
...j

Too bad you didn't have a receipt or something like that for it. Sometimes to stand behind high dollar products the maker would rather replace it for free then have an unhappy customer. You could keep the broken one for a spare parts in case it happens when you are out touring as keeping a couple links is suggested for a portable tool kit. Do you know what model it is? I come up with some pretty good search results . As far as piecing a chain back together some say it is ok and a lot suggest against it.

[Alex Ramon]

Sounds like the chain pin wasn't installed correctly. Those chains require a special pin when joining the chain. Here's a link to the replacement chain on JensonUSA that comes with the pin:
http://www.jensonusa.com/store/product/CH706C00-Shimano+Cn-7800+10Sp+Chain.aspx

And here's a link to a replacement pin:
http://www.jensonusa.com/store/product/CH309C00-Shimano+Cn-7801Cn-6600+10Spd+Chain+Pins.aspx

Unfortunately you can't get replacement links without getting the whole chain. Maybe your local bike shop has some extra links and pins kicking around.

[j beede]

If you can see the photo, you can see that the chain did not break at the "quick pin" link. This concerns me as now I need to figure out why the chain broke. FYI the chain is marked VIA, HG, and CN-7801.

[j beede]

(02-19-2010, 09:22 PM)Alex Ramon Wrote:  Sounds like the chain pin wasn't installed correctly. Those chains require a special pin when joining the chain. Here's a link to the replacement chain on JensonUSA that comes with the pin:
http://www.jensonusa.com/store/product/CH706C00-Shimano+Cn-7800+10Sp+Chain.aspx

And here's a link to a replacement pin:
http://www.jensonusa.com/store/product/CH309C00-Shimano+Cn-7801Cn-6600+10Spd+Chain+Pins.aspx

Unfortunately you can't get replacement links without getting the whole chain. Maybe your local bike shop has some extra links and pins kicking around.

I will make the LBS rounds today Alex. I am not too hopeful since Shimano makes so many different chains... the chances of finding spare links for my CN-7801 chain seems remote. I will try though. I am looking for inputs on what breaks (new) chains. I have seen side plates fail, but my failure looks like something "peeled" the side plate away from the pin.
...j

[JonB]

Alex Ramon Wrote:Sounds like the chain pin wasn't installed correctly

Beat me to it. In my experience chains only fail like that because of a weak link created by it not being installed properly.

My advice would be to take the outers and the pin off the broken link and install a SRAM Powerlink. This is basically a snap-together link, but the 10-speed ones are not designed to come apart. I always carry a few with me, so that if my chain does break I can bin the link and whack one of these in. These will work with Shimano chains as long as you buy the right speed.

[cyclerUK]

As JonB says -

Sram Power Link:-
http://www.chainreactioncycles.com/Models.aspx?ModelID=871

KMC Link:-
http://www.cyclestore.co.uk/productDetails.asp?productID=18885

These will also jeep the chain to the same length once you've removed the damaged one.
Check out your prefered supplier or LBS.
I prefer the KMC version but either will do the job.
There is a report that the Sram is not re-usable but the KMC is?

[j beede]

Found a semi-LBS that had a box full of chain bits... they had a length of CN-7801 that they gave me along with a pair of Shimano pins. I bought an SRAM link and a KMC as well for educational purposes. I'm heading out to the bench to see what I can do.
...j

[j beede]

UPDATE: Back in business... I replaced the twisted link using pieces of CN-7801 from the LBS and a pair of Shimano snap-off pins. Those Shimano snap-off pins are easy to install but binding was a problem. I spent about 20 minutes playing with the new link trying to get the kinks out.
...j

[deejays]

I have just upgraded from Ultegra SL to Ultegra 6700 groupset after a bike theft, as usual I chose a new Dura Ace chain (7901) after the Ultegra (6701) split at the connecting link early on.
I am running a triple chainset with a 28-11 cassette, I have always used shimano chains without issue.

The Dura Ace chain split on my first moderate hill, again at the connecting pin. The advice I was given from Evans was that the new Shimano chains aren't as robust as previous incarnations and with my build (6ft 1" and 17 stones) the power put through the chain and lateral movement with the triple chainset is stressing it too much.

I think they may have got the weight v strength balance wrong this time.
I was advised to use a SRAM (10sp) quicklink (£2.50)to connect the chain, and so far after 200 miles of commuting it's fine.

When I asked what chain the mechanic would put on a triple setup he said SRAM every time, I wasn't prepared to throw £50 away apparently the quicklink is a stronger connection than Shimano's special pin where both chains split under stress.

Dave S
Birmingham UK

[dave_sd]

I have a brand spanking new dura ace chain waiting to go on my bike and I plan on connecting it with a sram power link. hopefully nothing breaks on me. I've always used sram chains.