Campag 11 speed RD capacity

[ldamelio]

Quick question - will an early (2009) short cage Record 11 derailleur handle a 29T rear cog? I know that the answer is generally yes, but I found one obscure and complicated reference to something specific about the earliest 11s RDs needing some sort of modification. TIA.

[thwart]

If memory serves when Campy first released 11 spd, the rec’d maximum large cog for a standard cage RD was 27. They then made a running change (you could check the manufacturer sticker on the RD to see which one you had) to allow the use of a 29. Think there was a mod available for the early models.

However… in actual practice, it seemed that the difference was not that significant.

[RoosterCogset]

If it's on the cusp of working, would it be more likely that a 12-29 could be handled versus the 11-29?

[Mark McM]

Early Campagnolo short cage 11spd derailleurs can handle a 29 tooth maximum sprocket, so it might come down to a matter of capacity (maximum toot differentials of cassette and chainrings). A short cage 11spd derailleur should be able to handle a 12-29 cassette with 53/39 chainrings, but it may not have the capacity for an 11-29 cassette with 52/36 chainrings.

[robt57]

I run a 11-30 SH wheel w/pre 2015 SR group. I never use the 11, so its a 10 speed.

[oldpotatoe]

Originally Posted by ldamelio

Quick question - will an early (2009) short cage Record 11 derailleur handle a 29T rear cog? I know that the answer is generally yes, but I found one obscure and complicated reference to something specific about the earliest 11s RDs needing some sort of modification. TIA.

It was this, image 2...an extra hole winding up that spring a wee bit more to keep the upper pulley off the biggest cog..But in actual practivce, it really wasn't needed.

[ldamelio]

Thanks Peter - the graphic makes it perfectly clear. As always, you have the definitive Campag answer.

[gfk_velo]

Originally Posted by oldpotatoe

It was this, image 2...an extra hole winding up that spring a wee bit more to keep the upper pulley off the biggest cog..But in actual practivce, it really wasn't needed.

Well, yes and no.

The part that the spring locates into changed between the very earliest, 27T compatible RDs and the slightly later ones, for 29T. Those that were fitted to the RDs for 29T have a longer "drive" for the worm gear as well. It wasn't solely a matter of swapping which spring location was used.

As OP says, in most cases it didn't matter because the hanger would be long enough to accommodate even with the original H Screw drive and original spring placement - but on some really short hangers, at or around the 24mm mark, centre wheel to centre top pivot bolt, with differing "hook" placement, the new H Screw drive was required.

I still have a bag of the replacement H-Screw drives that the factory sent out to SCs to make the change, somewhere about the place.
The part never carried a customer code, as normally the H Screw drive is sold as part of the complete cage.

The amount of chain wrap provided by the 11s short cage would allow 12-29 on all four chainring combinations offered by CA at the time, provided the chain was correctly sized using the small-small route, although, only for the chainring combination that was fitted when the chain sizing was done - so a chain sized for 50/36 would not necessarily allow a 53/39 to be run, although that was / is itself very dependent on exact frame geometry / hanger length & configuration.

In some cases we have seen, 11-29 shifting is slightly "off" because of the RD's tracking angle, the amount of chain engagement on the smallest sprocket and the difference in the sprocket spacing 11>12>13, vs 12>13>14 which is part of the reason that CA never recommended the first generation 11s RDs (up to 2015) for use with 11-29 (although many use them perfectly successfully with those ratios). As usual, it's the edge cases where the functionality is not great.

[Gwerziou]

Perhaps a wee bit off tangent - the late-era long-cage 10 speed Record derailleurs handle an 11-32 11 speed cassette perfectly well with pre-2015 11 speed shifters.

The pre-2015 Athena 'triple' rear derailleurs also do this, and you can take the cage off of one and put it on a Record or Chorus from that era if you want it to have a more high-zoot vibe.

This pre-2015 11-speed stuff is, along w mechanical 12 speed, my favorite drivetrain. I'm building up a little stash of pre-2015 parts as time goes by to make sure I can always have that experience in the future.

[Mark McM]

Originally Posted by Gwerziou

Perhaps a wee bit off tangent - the late-era long-cage 10 speed Record derailleurs handle an 11-32 11 speed cassette perfectly well with pre-2015 11 speed shifters.

I tried this on one of my bikes without success. The indexing was spot on, but no adjustment of the chain length or cage spring tension prevented the jockey wheel from riding against the 32t sprocket when in the small chainring (50/34 crank). Perhaps it was an issue with the derailleur hanger length. The hanger bolt to cage pivot length is longer on Athena 11spd derailleurs, so I was able to use an Athena 11spd derailleur with success.

[roguedog]

Interesting. I was just looking into this and found this video

Caveat: I dunno how valid it is IRL

Was just looking into the wolf tooth roadlink. look through the comments. I found that more informative than the video.

Would be interesting to get OP's take on this

[Gwerziou]

I'm running a René Herse crank with a 48/32... It works incredibly well, just got back from a ride!

[oldpotatoe]

Originally Posted by roguedog

Interesting. I was just looking into this and found this video

Caveat: I dunno how valid it is IRL

Was just looking into the wolf tooth roadlink. look through the comments. I found that more informative than the video.

Would be interesting to get OP's take on this

Using a longer cage rear der.....

[roguedog]

Hey OP I saw in the comments that there's reference to a rear der that was labeled HO. Is that the longer rear der you're referring to or some other one that you recommend?

[Mark McM]

Originally Posted by roguedog

Hey OP I saw in the comments that there's reference to a rear der that was labeled HO. Is that the longer rear der you're referring to or some other one that you recommend?

HO means "Hydraulic Optimized". This label refers to drivetrain components modified for the slightly wider chainline which resulted from the 135mm axle length used by most disc brake wheels/frames.