Campag 11 speed backpedal woes

by nicdoye   May 15, 2014  

I have a problem with a newly installed 11 speed system.

On my summer bike (short chainstays), on the biggest two sprockets, the chain is slightly fouling the sprocket below it. Now you don't notice this in normal riding, but if you stop and backpedal to start again, the chain will move to the lower sprockets, and go slack - thus making it impossible to start again. A bummer on a steep hill. (It may happen in the 12 and 13 sprockets too, but I rarely use those. Wink )

This is nominally a Campag set-up, but a couple of the parts are third party, which is probably the cause of the problem. The chainline is good (the BB came with the Chainset, so it should be!) so it's not that. The rear mech adjustment is spot-on.

Has anyone else had this problem? Especially with either the chain or cassette listed below?

List of bits:

  • Campagnolo Athena 11 Ergopower Levers
  • Campagnolo Athena 11 short rear mech
  • Campagnolo Athena 11 front mech
  • FSA SL-K 10 speed 53/39 chainset
  • KMC X11-L chain
  • Miche Primato (Campagnolo compatible) 12-25 and 12-29 (both have problems) 11 speed cassette
  • Campagnolo 11 cables

16 user comments

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Not a whizz here but my LBS informed me that for a 12-29 you need a long rear mech (as I was debating the relative cost of a Athena 11 speed 52/36 crank v 12-29 cassette (and long mech) for a hilly event coming up).

posted by NickK123 [70 posts]
15th May 2014 - 12:14

3 Likes

Not true (duff LBS advice), Campag 11 speed systems can handle up to a 29 teeth cog as standard.

Is the chain length correct when you test in on both cassettes? If not this then it really does sound like a minor bit of indexing trouble.

posted by sorebones [110 posts]
15th May 2014 - 12:20

3 Likes

I'm guessing 39t to 25t/29t is the problem rather than 53t ??

What frame and wheels ?

I run a 37t front 27t rear and haven't noticed this, but then mine's Chorus11
throughout....

Campagnolo list the Athena/Chorus 11 as being able to handle a 29t cassette
in short and long cage sizes Smile
http://www.campagnolo.com/repository/documenti/en/Rear_derailleur_EN_Rev...

still on the 3rd switch-back of Bwlch !

posted by therevokid [714 posts]
15th May 2014 - 12:21

3 Likes

if my chain and cassette are wearing to the point I need to change them, usually the earliest indication is when the chain won't turn smoothly when I backpedal, and catches or changes cog...

posted by SPAM Naval [139 posts]
15th May 2014 - 13:02

2 Likes

I have essentially the same setup on my summer bike, Athena throughout apart from a FSA SL-K 50/34 chainset and a Miche 12-27 cassette (not sure what the chain is since it came new with the bike) and I don't have the issue you describe so I don't think it's a compatibility issue between the parts

posted by pirnie [185 posts]
15th May 2014 - 13:10

3 Likes

sorebones wrote:
Not true (duff LBS advice), Campag 11 speed systems can handle up to a 29 teeth cog as standard.

Thanks 'Sorebones' - will follow-up with LBS.

posted by NickK123 [70 posts]
15th May 2014 - 14:05

2 Likes

Yes, it's on the 39. (Also happens on the 53, I checked).

Thanks for that link. I was under the misapprehension that the max capacity of the short cage was 26, so was surprised when it worked with 31.

The bike is a 1992 Specialized Allez Epic (bonded carbon fibre frame) with c.2001(?) Mavic CXP33 rims on Campagnolo Chorus hubs.

One random thought is that the wheel isn't completely straight in the frame, but with vertical dropouts that's unlikely.

http://worldofnic.org
1992 Specialised Allez Epic
2009 Ribble Winter Aluminium

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posted by nicdoye [23 posts]
15th May 2014 - 14:27

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@SPAM Naval New chain and cogs Plain Face

http://worldofnic.org
1992 Specialised Allez Epic
2009 Ribble Winter Aluminium

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posted by nicdoye [23 posts]
15th May 2014 - 14:29

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Have you checked that the tension screw has been done up on the spring for the rear mech cage?

On a shimano mech its called the B-screw and its located on the spring around the mech hanger bolt. I ask as Campag mechs come as standard with this tension undone... by tightening up you will effectively bring the top jockey closer to the cassette teeth. This should provide slicker shifts, but equally will hopefully let you know if there is a problem with either cable tension, or indeed the straightness or your rear mech hanger.

That would be where I'd start.

posted by Jimmy Ray Will [285 posts]
15th May 2014 - 14:30

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@pirnie OK, glad to get info from someone uses Miche cassettes too. I was a bit worried about that because the cogs are fairly flat, with no shaping to the teeth at all (compared with my Campag 9sp ones).

Here's a link to a picture.

Probably ancient history to some of you. Wink

http://worldofnic.org
1992 Specialised Allez Epic
2009 Ribble Winter Aluminium

nicdoye's picture

posted by nicdoye [23 posts]
15th May 2014 - 15:01

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@JimmyRayWill that's interesting. Never heard of that!

http://worldofnic.org
1992 Specialised Allez Epic
2009 Ribble Winter Aluminium

nicdoye's picture

posted by nicdoye [23 posts]
15th May 2014 - 15:02

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Still messed up. I think it's the rear wheel - it looks like it's diagonal or at least offset in the frame. (My other rear wheel sits dead on).

I stripped the wheel down to the axle, and that isn't bent, as far as I can tell. So, the next step is to admit defeat and go to the LBS.

http://worldofnic.org
1992 Specialised Allez Epic
2009 Ribble Winter Aluminium

nicdoye's picture

posted by nicdoye [23 posts]
2nd June 2014 - 9:40

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Sounds to me like the derailleur hanger is bent towards the front of the bike, possibly the dropouts are bent too if the wheel is not square. Has the rear triangle taken a whack with the wheel removed?

posted by srchar [60 posts]
2nd June 2014 - 11:01

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Certainly had similar on a previous training frame @srchar

Anyone got any advice on checking the alignment of the dropouts and the derailleur hanger? (Previously, I've looked at the hanger by eye).

Luckily, being old, the dropouts and hanger are aluminium (the frame is carbon), so I have a hope of straightening the hanger.

http://worldofnic.org
1992 Specialised Allez Epic
2009 Ribble Winter Aluminium

nicdoye's picture

posted by nicdoye [23 posts]
2nd June 2014 - 11:32

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+1 for checking the derailleur hanger. The tool for that (Park Tool DAG-1) is around £50, so take it to the LBS.

The wheel alignment problem sounds odd. Get them to check the frame alignment too. Something might be wrong!

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posted by drmatthewhardy [316 posts]
2nd June 2014 - 22:06

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You can't really check hanger alignment by eye, but you don't need to splash out on a tool either if you have an old bolt-on wheel hanging around in your shed or on another bike.

Screw the axle thread into the derailleur hanger so that the wheel is outside the rear triangle (your bike will now appear to have two rear wheels). If the hanger is straight, the two wheels will be in alignment around their circumference. If not, you can either use the wheel as a lever to tweak the hanger, or just replace the hanger.

posted by srchar [60 posts]
3rd June 2014 - 10:15

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