How big cassette on Campagnolo Record rear derailleur

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Tillquist
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by Tillquist

How big cassette can I use with a Campagnolo Record rear derailleur, the short model.

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Frankie - B
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by Frankie - B

From the top of my head, Campa recommends a 29. Are the climbs that Steep in Denmark Morten?
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Tillquist
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by Tillquist

No no, but a friend of mine bought my BH G6 with Record and he cycles sometimes in Mallorca.


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bikerjulio
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by bikerjulio

Campy appears to spec the largest sprocket capacity as being the largest one they make, rather than the true number.

They quote 29T in 11-speed, which happens to be their largest sprocket. On another thread there are several people running Shimano 11-32 11-spd cassettes successfully with Campy RD's. http://weightweenies.starbike.com/forum/viewtopic.php?f=3&t=130465

The limitation is upper pulley wheel clearance, so the frame hanger dimension can impact this. Plus the RD will need to be adjusted to achieve clearance.

The second issue is chain takeup. A short cage can take up 33 teeth total, with full operation. So you can do the math. The options are either to size the chain to be safe in big-big with the short cage in which case the chain will go slack in the extremes of cross-chaining when in the small ring, or use an Athena triple RD.

Staying in the world of Campy, and with a short cage, then a 12-29 cassette paired with a 50-34 crankset = 33T total and is the lowest gearing with full operation.
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Calnago
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by Calnago

Yes, pretty much agree with @Bikerjulio's post above. The one caveat being that if you're using an early 2009 version 11sp derailleur there is a modification that you should do in order to use it with the 12/29 cassette. It is simply installing a different spring tensioner wheel (that the b screw turns) which will allow the upper pulley to be pulled a little bit further from the sprockets. They are available as a separate part.
I have my 11sp set up with a chain length that can use any combination of cassettes from 11/23 to 12/29 with a 53/39 up front without the chain going slack in the small/ small (39/11) combination. I also have compact cranks which I rarely put on but I would use a shorter chain with them. Best gearing I've ever used was while spending some weeks in the Alps... I used an alloy Record triple crank (53/39/30) crank with a 12/25 cassette. Nice close ratios using any of the rings up front. Maybe not the sexiest setup these days but it sure was nice to have and never have to worry about changing out gearing for a given days ride.
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by graeme_f_k

bikerjulio wrote:Campy appears to spec the largest sprocket capacity as being the largest one they make, rather than the true number.

They quote 29T in 11-speed, which happens to be their largest sprocket. On another thread there are several people running Shimano 11-32 11-spd cassettes successfully with Campy RD's. http://weightweenies.starbike.com/forum/viewtopic.php?f=3&t=130465

The limitation is upper pulley wheel clearance, so the frame hanger dimension can impact this. Plus the RD will need to be adjusted to achieve clearance.

The second issue is chain takeup. A short cage can take up 33 teeth total, with full operation. So you can do the math. The options are either to size the chain to be safe in big-big with the short cage in which case the chain will go slack in the extremes of cross-chaining when in the small ring, or use an Athena triple RD.

Staying in the world of Campy, and with a short cage, then a 12-29 cassette paired with a 50-34 crankset = 33T total and is the lowest gearing with full operation.


All the above broadly correct but as stated I'd suggest it should be in letters of fire six feet high, watch the overall capacities - too little chain wrapped to accommodate a gear selection + that gear selected = VERY expensive noises!

If the hanger exceeds 28mm c-c length you can go bigger than a 29 but the reason that Campag recommend (and make) a 29 is also connected to FD depth - if you run 50x34, depending on the seat angle, in order to accommodate the chain striking the right part of the FD to up-shift / downshift properly and / or not hitting the inside-top of the FD bridge when in the big to big combination whilst also clearing the lower FD bridge when in the small to small combination, there *may* not be enough physical depth in the FD to allow you to run a wider cassette.

Campag's spec assumes that the frame falls within the overall parameters that they set and the system will work fine wthin those parameters - there will be instances where you can exceed the specified capacities but in most cases it'll be "suck it and see" and if you are investing alot of money in kit, you really need to know it's going to work without any hitches.

Last, if the rear hanger length exceeds 28 mm you may also start to run into issues, depending on the overall ratios of the cassette (i.e. "starting" size relative to "finishing" size) especially around the small sprocket end of the cassette, where the top jockey is too far from the sprockets to allow a clean, quick change up or down, if you have the H screw set so that the top jockey doesn't crash into the biggest sprocket in the small ring - big sprocket combination.

HTH
Graeme
Velotech Cycling Ltd, Campagnolo Main Technical and Service Centre, UK
A Tech-Reps work is never done ...
Head Tech, Campagnolo main UK ASC

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