Chainsuck on brand new Di2 9070 Venge Boonen Ltd build

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venge115
Posts: 3
Joined: Mon Jun 10, 2013 7:35 pm

by venge115

My bike shop just finished assembling my dream bike and it suffers from a wicked case of chainsuck. I have done a couple of builds myself and know my way around wrenches, but this being a Di2 I let the experts handle it...or so I thought. I have studied the relevant chainsuck guides I could find and checked off every item on the suspect list: chain and chainring (11 spd Specialized sworks) are flawless - well lubricated and no visible defects. Chainsuck happens when I downshift from the large chainring while in the second largest cog in the cassette. Has anyone experienced this with the new Di2 11 spd? My only lead: I noticed that the rear derailleur tension was not very high, is it possible that my mechanic missed something that accounts for the wimpy pull? Also, what should I be looking for in terms of damage in case of chainsuck? I have some cosmetic damage to the chainstay, but should I be worried about the derailleurs derailleur hanger? In case the shop did screw this up I plan on asking for replacement parts. This fatal flaw is heartbreaking, I cannot bear sawing into the frame and cranking the derailleurs once more. Also, I am concerned that this is unusual enough that the guys at the shop won't invest the time to get it right; time is money and they have more bikes to build.

http://i.imgur.com/8lr6CQC.jpg?1

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Calnago
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by Calnago

Yes, that truly does suck, pardon the pun. Can't comment on whether your di2 is set up correctly, but once I did a brand new build on Campy Super Record 11, perfectly setup yada yada, but I had the exact same kind of chain suck you are describing. It drove me nuts and was more than just a freak one time occurrence. So, I took some yellow tape with me next time and when it began to suck I stopped pedaling immediately, got off the bike, and put some tape where it appeared to be getting hung up for some reason. Came home, disassembled the crank, cleaned it up super clean (otherwise I still wouldn't have been able to find the problem), then really looked at all of the teeth for anomalies. Sure enough, right around where I had placed the marker tape, there was a very slight burr on one of the teeth. Marking it with the tape was useful because it sort of gave me some reassurance that this might be the problem since it was right where the tape was. So I just took a very fine round file and made a couple of passes over the burr and voila... no more chainsuck. It's the one and only time I've ever encountered that, but that was the issue.

I also really don't care for chainrings other than those that come with the group. I've just found that nothing works better than Dura Ace chain rings on Dura Ace and Campy chain rings on Campy. That's not to say that others won't do the job, but I just don't think they do it as well.

Hope you find the source and get it resolved. Nothing worse than getting a new top end bike and having it work anything less than perfect.

Beautiful bike by the way. Would have been nice if they matched the red on the fork with that gold color on the rest of the bike though...
Colnago C64 - The Naked Build; Colnago C60 - PR99; Trek Koppenberg - Where Emonda and Domane Meet;
Unlinked Builds (searchable): Colnago C59 - 5 Years Later; Trek Emonda SL Campagnolo SR; Special Colnago EPQ

by Weenie


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venge115
Posts: 3
Joined: Mon Jun 10, 2013 7:35 pm

by venge115

It has happened three times. After the second time, at which point it dawned on me what was happening, I inspected the chainrings and found a bur. I carefuly removed said bur and went on my merry way only to have it happen again. I suspect the bur got there in the first place due to the chainsuck, it looked like chain inflicted damage. I will give it another go around, maybe I didn't fix the problem completely, but I was rather thorough fearing another incident.

I agree with your view on component mixing, just not sure how to get the new DAs on my Rotor power.

Thanks. Glad to hear you tamed the problem on your bike, gives me hope.

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Rick
Posts: 2034
Joined: Sat Aug 29, 2009 4:30 pm

by Rick

Tight link in a new chain can cause that.
Try flexing chain and re-lubing. Then go break it all in for ~200 miles.

venge115
Posts: 3
Joined: Mon Jun 10, 2013 7:35 pm

by venge115

Checked for tight links and found nothing...already done over 200 miles, should be good to go.

xclemjustinx
Posts: 9
Joined: Mon Jun 10, 2013 9:28 pm

by xclemjustinx

the crank your are using is 10 speed not 11 speed

Valbrona
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Location: United Kingdom of Great Britain and Northern Ireland

by Valbrona

venge115 wrote: My only lead: I noticed that the rear derailleur tension was not very high, is it possible that my mechanic missed something that accounts for the wimpy pull?


Er, yep.

415brian
Posts: 52
Joined: Fri Sep 30, 2011 4:48 pm

by 415brian

If other avenues are fruitless, try a different chain. For example, if you're currently running a Shimano CN-9000 chain, try the 11-speed KMC X11SL chain ($65): http://amzn.com/B004JKGUMO

While running non-Shimano chainrings, I had noticeably better shifting with a KMC chain on an Ultegra Di2 build.

em3
Posts: 883
Joined: Tue Dec 23, 2008 2:57 pm
Location: NYC

by em3

...based on the pic, it appears your chain maybe too long. Post a pic with chain in small chainring/small cog position for better assessment.

Also, did you make sure that the rear mech hanger was aligned with the proper alignment tools.

Lastly, protect your frame...get some Lizard Skins Leather Patches and place them behind the chainrings on the chainstay.
EM3
______________

ryker
Posts: 40
Joined: Sun May 19, 2013 1:01 am

by ryker

^Yeah check your chain length!

maxxevv
Posts: 2012
Joined: Wed Feb 09, 2005 4:51 am

by maxxevv

From the pict, indeed the chain looks a tad too long.

Shift it down to the smallest cog, while in the smallest chainring. At this position, the chain should just clear the pulley arm.

If the chain touches the pulley arm, its too long.

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Calnago
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by Calnago

Yes, looking at the pic again I'd say the chain is definitely too long. Not sure if its the cause of the chain suck or not but worth getting straightened out nonetheless.
Colnago C64 - The Naked Build; Colnago C60 - PR99; Trek Koppenberg - Where Emonda and Domane Meet;
Unlinked Builds (searchable): Colnago C59 - 5 Years Later; Trek Emonda SL Campagnolo SR; Special Colnago EPQ

thisisatest
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Location: NoVA/DC

by thisisatest

I would also check hanger alignment. Even brand new hangers sit at an angle when the frame's surface is not square with the wheel.
and make sure that the inner ring is facing the right way, and that the spider it's on does not interfere with the slight dish that ring has.

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Geoff
Posts: 5395
Joined: Sat Dec 13, 2003 2:25 am
Location: Canada

by Geoff

+1 on the chain length. What inner ring are you running?

Cool bike, BTW...

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xclemjustinx
Posts: 9
Joined: Mon Jun 10, 2013 9:28 pm

by xclemjustinx

How can you determine if his chain is too long or too short from that picture? In order to see if his chain is the correct length you must put it in the big chainring and the smallest cog in the rear and see if the pulley wheels are 90 degrees of one another.

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