Cycling UK Forum

Hello everyone. I'm running 9-speed Campagnolo components on all three of my road bikes which are currently fitted with 13-26 teeth cassettes and Campag Veloce SHORT-CAGE rear-derailleurs. Due to long-covid fatigue I've been wanting to gain an extra two or three teeth for largest cog at rear in order to be able to better tackle the hills here in Eat Sussex, and I see that Campag offer a 14-28, while Miche Primato offer Campag-compatible cassettes with either 13-28 or 12-29 (both 9-speed). The old information was that Campag short-cage derailleurs were only suitable for a maximum rear cog of 26 teeth, however that was before the availability of 28 and 29 teeth cassettes for 9-speed. Do any of you have real-world experience of using a 28 or 29 tooth cog with a Campag SHORT-CAGE rear-derailleur? I've seen some people saying that it's feasible, and of course I'll probably need to fit new and slightly longer chains, but does this lead to any issues with smooth shifting? One other option is to fit one of those Wolf Tooth Road Link (other brands are also available) to extend the rear derailleur a tad. They bolt on to the frame dropout and then the derailleur bolts onto the extender. I'm not wanting to purcase medium-cage derailleurs for my bikes unless absolutely necessary due to cost. Any advice on this would be greatly appreciated

Not the answer you're looking for, having never tried anything larger than 26T with old short cage Campag rear mechs, but can you not fit a smaller front chainring (or convert to triple)? That would make a bigger difference.
Hope you make a full recovery to Long Covid. Dreadful illness.

I wouldn't want to go down the triple route, but yes...I will look into the possibility of slightly smaller version of compact chainset. The only real issue with that option is whether or not my front derailleur would be able to slide down low enough to meet the smaller chainrings, and I suspect it won't as two of my three bikes have braze-on front-derailleur mounts. Cheers anyway

Are you running a 50 x 34 chainset? Also, is the front mech bolted onto a hanger or does it have a clamp attaching it to the seat tube?

Edit: see we cross-posted. What's the chainset?

Yes, currently have Campag compact chainset with 50/34 and the front derailleurs are braze-on on two of the bikes while the most recent bike has seat-tube clamp version.

Going from a 26T to a 28T is not going to make much of a difference. If you really want to get a significantly lower gear, you'd be better off changing the chainset. Or a longer cage, bigger rear cog(s), and longer chain. Just me 2cts. There will be other suggestions coming along soon.

The only difference in the 9 and 10 speed Campag Long, Medium and Short mechs is the length of the cage, the parallelograms are the same. I run a medium cage 9 speed Veloce triple setup (52-42-30, 13-28) with no problems so I think a short will cope with a 28 tooth sprocket. As others have said upthread it won't make a big deal of difference to the gearing but smaller chainrings (or both) will.

all mechs have a nominal total capacity (TC) and a largest sprocket capacity (LSC). Manufacturers are often conservative here, perhaps because the true values for both will vary with frame design and exact gearing choice. For example, derailleur chains can only be lengthened in increments of 1". This means that in some installations, the RD may be able to operate ~2T in excess of it's stated TC. In any event, running out of TC is usually no big deal, in that it tends to affect small-small gear combinations first, ie. you first lose the ability to tension the chain when using gears that are best avoided anyway.
LSC more obviously varies with installation eg. with changes in hanger length. However, the exact wheel position affects it, as does (eg. with a slant parallelogram) the lateral position of the derailleur. Sometimes adding a washer (or two) behind the mech mounting bolt will increase LSC enough to make a difference. Any RD that uses a spring in the upper pivot (B tension) is likely to announce that you have used all the LSC by promoting (noisy) contact between the guide pulley and the largest sprocket when backpedalling.
So you will have to assess your particular installation, both for LSC as is, as well as for (if any) scope for changes.
Note that the sprocket/pulley design also affects LSC. so if a sprocket with a shorter tooth form is used (eg. HG instead of UG) then LSC might be usefully increased.

btw 'Bikeingreen' do clever chainrings that defy the usual limits owing to their unusual design. They don't make every size/fitting, and nor do they fit every bike, but IIRC if you have a 110 mm BCD and have a little clearance to the chainstay plus some available leftwards FD movement you might be OK..

I'm not seeking a significantly lower gear, just two or three (if 29 tooth works), because I want to stay with 9-speed and I don't want to have to splash out on new rear mechs. Any more answers on whether 28 or 29 tooth cogs will work with short-cage on Campag most welcome, but no more suggestions of changing rear-mechs please.

Well then, given it's only £33 for a Miche Campag-compatible 9 speed cassette with a 28T or 29T cog, give it a whirl and let us know how you get on.
https://www.spacycles.co.uk/m8b174s150p ... e-Cassette

This website (https://branfordbike.com/rear-derailleur) has a lot of info on old Campagnolo rear derailleurs and agrees with Brucey that the RD will cope with a 29T cassette sprocket but it's possible you might be a bit short on TC meaning little chainring- little sprocket may result in a bit of chain sag (not a real problem as it's derailleur safe and not a combination you want to run anyway). I can't personally vouch that it will but as Jezrant says it's worth a punt for £33.

Cheers guys. Yes, I agree.. I'll take a punt on the Miche Primato 12-29

I realise you have the answer you need now, but maybe you might be interested in what I've done...

I have 2 Campag equipped bikes, both 10 speed, so not the same as yours but a similar era.

One is a race bike and with that I went as far as I could with the original rear mech, so compact chainset and 29 sprocket. The mech struggled with the wrap but otherwise worked OK, but I fitted a longer cage which dealt with the wrap problems. I live near the Pyrenees, so the gear still wasn't really low enough, so I fitted a hanger extender and a Miche 32 sprocket (the biggest Campag pattern sprocket I can find, no longer made but not hard to find). The gear is OK for now but the shifting isn't as crisp as it used to be.

The other is a CX bike which now gets used as a touring bike. I went down the triple route with that one - it has a Racing T chainset and a racing T rear mech, but Shimano splines on the hub. That quickly ran up against wrap problems which I tolerated - they came about because I used a 26 inner ring, not the 30 they usually have. I ran it with a 30 Marchisio sprocket which wasn't really big enough, so then I fitted an extender which made it work with a 32, later a 34, but of course the wrap problems were worse and the shifting became a bit vague. Really I wanted lower gears still, but at that point I was already way beyond what the rear mech could comfortably cope with, so thanks to a tech article by Chris Juden, I bought a modern 10 speed Shimano GRX rear mech which has huge wrap, will cope with up to a 40 sprocket, was cheap and works with 10 speed Campag shifters. I had to tinker with the spacing on the cassette a little using beer can shims, but that wasn't difficult. Inevitably I fitted a 40 sprocket because I found a cheap cassette extender, and because, well, I could. I now have an insanely low bottom gear, very slick shifting and no wrap problems. The gear is so low I might replace the 26 with a 30, which is a nice dilemma to face. So what I'm saying is that the whole thing was quite unsatisfactory until I found a modern rear mech which was compatible with my shifters and had the capacity I needed, so if you want lower gears still, I'd be investigating that, IIRC it is possible with 9 speed Campag. In fact my tandem has 9 speed Campag shifters running with a 9 speed XT rear mech on a 34 cassette but that requires a shiftmate to get everything to play nicely together.

Campagnolo specs are conservative, but also very dependant on the entire setup, ie: front ring differences, chainstay and chain length, the specific derailleur model and hanger geometry.

For example I have one bike (running 9 speed like you) where I can only just manage to get it to work with 48/34 an a 12-27t, I have another happily running 48/34 with an 11-28t and it could probably go further.

For a bit of encouragement I also have one 9speed setup, but using a 10speed rear derailleur with published 29t max sprocket size running 46/30 with an *11-34t* cassette and yes, it does work, it is right at the limit on the 34t sprocket, and a little noisier than it should be, and I can't run in the 11t sprocket using the 30t chainring but I never would anyway. It works acceptably as a bail-out gear setup for my use. I did try it with an 11-32t and it was 100% happy with the 32t sprocket.

Campag specs are based on what they make, up to a point and as Brucey & others have said, are slightly conservative because everything from rear hanger geometry to chainstay length and chainstay angle play into both the maximum distance that can be attained from top jockey centre to wheel centre and how much chain will need to be wrapped.

As others have said, the parallelogram geo of the 3 9s derailleurs is the same - they are the same parallelograms.
The design and the offset of the upper pivot are also the same & are shared with the 10s RDs of the same basic design.

Those 10s derailleurs list a maximum "big" sprocket of 29T in the case of medium and long cage and 26 in the case of short cage - but that 26 for short cage is based on what Campagnolo make and expected use-case - because they're also relating to chainrings and chainring difference - and their compatible chainring differences at the time were between 10t (42-52) and 22t (triple, 30-52).

The all also share the same tracking angle, which sets the optimum range of differences between the biggest and smallest sprockets. In all three cases, the recommendation is an 11t smallest top sprocket, with maximum tooth differences at the cassette being given as 16t for the short and medium cages and 22t for the long cage.

Lastly, total capacity - or the ability to wrap enough chain to give correct chain tension and allow both big-big and small-small combinations, without over-stressing the springs at the top or bottom of the RD when fully extended - is given as 30, 32 and 38t.

What this means is, you could run a 29 (or maybe a 30 in most cases) with a short cage RD but only if you restrict your chainring difference inside the range that Campagnolo recommends for chain wrapping purposes. So - 13-29 gives a 16 tooth rear difference (the max recommended) allowing a theoretical max 12T difference at the front - so 42-52 would be OK but 39-53 (for the sake of argument) wouldn't.

There is an element of suck-it-and-see unless you have the time and ability to compare your frame and hanger design to Campagnolo's published specification range.

As a real rule of thumb, the greater the distance that your hanger allows from wheel centre to top pivot bolt centre, the bigger the biggest sprocket the RD can handle is - the principle on which Wolf Tooth extenders work & BITD, we all knew that SunTour vertical dropouts allowed us to run bigger biggest sprockets than traditional road ends, for this reason. Campagnolo's expected range for that dimension is 24 - 28mm which covers most hangers in the market & it's the same range as Shimano and SRAM specify (unsurprising). If you are at the 28mm end of that range, you may be able to squeeze and extra tooth ...

For a good shift across the cassette though, you need to respect the maximum big to small sprocket range of the RD because that maintains the amount of chain between the top jockey of the RD and the cassette within a range that the index system can compensate for.

So, all that having been said, if you can find a 14-30 cassette, that might do the job for you, with a 10t difference "up front".
Losing an 11, 12 or 13t smallest sprocket doesn't sound like it'd be a problem.