Campagnolo Triple - front chainring needs lower gears

[aoxomoxoa]

Hi,

I'm currently running a Centaur 50-40-30 front chainring on my Roberts Audax bike, with 12-28 at the rear. I'm going to be doing the Pyrenean Raid in the summer and am thinking I'll need lower gearing given my age (late 50s) and overall fitness (adequate but not stellar), not to mention the overriding sense of fear!

My understanding is that I can't do anything significant with the cassette, so am thinking about replacing the existing inner ring at the front with a smaller one.

My questions are:
- can I fit a smaller TA (or other non-Campy) ring in place of the 30, and will the existing changer work OK? I'm thinking about a 26 or 24 sprocket ring.
- will this give me a worthwhile improvement in gearing?

I've searched the forum but haven't found an answer to this, so apols if it's already been asked and dealt with.

Cheers.

[tatanab]

Yes.
The PCD of the inner is 74, the old MTB standard. I have a 24 TA ring on my Campag triple. Existing triple front mech works just fine. It will give you a gear 5" lower which might make all the difference. It is the same bottom gear that I had when I rode the tourist version of the Raid, and it saw a fair bit of use.

[pete75]

Campag triple chain set has 74bcd on the inner ring and 74bcd are available down to 24 tooth. Campag triple front derailleur spec has a minimum ring size of 30 tooth. In practice this means it will handle 28 and may handle 26 or 24.

[Mick F]

What rear mech have you got?
The Long Campag may be ok, but if you have a Medium, it won't have the capacity for the take-up.

Saying that, if I wanted a longer mech, I'd just buy the two sides of the cage. Cheaper than a whole new rear mech.

[tatanab]

The Long Campag may be ok, but if you have a Medium, it won't have the capacity for the take-up.

Saying that, if I wanted a longer mech, I'd just buy the two sides of the cage. Cheaper than a whole new rear mech.

True.
I have medium cage working 48/36/24 with 14-28 just fine, but 50/40/24 with 15-28 on the back just would not work without a long cage and I did exactly what MickF suggests in just changing the plates on the jockey cage.

[Mick F]

TBH, I thought about making my own cages. Sort of half way between Long and Medium.

I know there's a tube thingy on the top of the outer cage, but that may come off with a little persuasion. Can't be too difficult to cut and file to make a good job, and mine would be "different" and "stylish"

[aoxomoxoa]

I've just measured the rear mech, which is about 74mm from pulley bolt to pulley bolt. I'm guessing that's a medium rather than a long cage.

[tatanab]

Measured from my box of mechs
short = 45
Medium = 74
Long = 90

editted - why not try it with the mech you have. It might just work. I have had a set up that worked on one machine but not on another. You might find the chain is slack and will not run on a couple of the little sprockets when on the little ring but so what since you would not use them any way. So try it first before trying to find spare plates for the rear mech.

[aoxomoxoa]

Yes, that's a good approach - thanks. Having had a quick look, it seems that new long cages are only available in 10 speed. If it turns out I do need a new cage will they be compatible with 9 speed systems? Alternatively, do you know who might sell just the side plates so I can convert my medium cage into a long cage?

Many thanks.

PS: Is it pretty straightforward to switch the inner rings, or does it require Campag-specific tools?

[Brucey]

DIY job from way back;



from here;

http://www.hetchins.org/504g.htm

nice bike, but not for riding down farm tracks....

cheers

[tatanab]

Yes, that's a good approach - thanks. Having had a quick look, it seems that new long cages are only available in 10 speed. If it turns out I do need a new cage will they be compatible with 9 speed systems? Alternatively, do you know who might sell just the side plates so I can convert my medium cage into a long cage?

10 speed does not matter because that is only the distance between the plates whch is set by the jockey wheels you already have. The problem may be if the 10 speed plates have the B screw adjuster down at the upper jockey while your 9 speed might have the B screw adjuster up at the gear hanger. Really that is not a problem because you would simply drill out the fixings and remove the B screw from the plate. This then gives a different problem depending how fussy you are. Making this modification means that the jockey cage has no stop for wrapping around. This means that when you take the wheel out the cage wraps around on itself because of the tension spring and you would have to wind it back up to put the wheel back in. Not a problem, it simply makes your wheel replacement slower. Changing the fixed jockey plate is not a problem because it is held to the body of the mech by a circlip, unless you have Chorus or Record. You see all this depends on knowing PRECISELY what your rear mech is, how you cope mechanically and so on. Source of parts is usually Mercian.

Is it pretty straightforward to switch the inner rings, or does it require Campag-specific tools?

Inner ring is held on by 5 allen key screws. No problem.

Editted - phew that's a lot of "no problems"

[RickH]

Is it pretty straightforward to switch the inner rings, or does it require Campag-specific tools?

Inner ring is held on by 5 allen key screws. No problem.

The only thing I would note is that you have to remove the chainset to change the inner ring - the outer & middle can be removed/replaced in situ, plus it is easier to do once you have a smaller inner as the inboard fastenings for the larger rings are not obscured by the small chainring.

Rick.

[byegad]

My QNT runs a campag Veloce tiple from 2007. It has 24 40 55 rings. The 24 was the smallest I could fit. Also consider an 11-34 rear cassette.

[CREPELLO]

I'd say it should work with a 26T ring, 24T may be pushing it. The gear change may not be quite as crisp shifting small to middle and there is an increased risk of the chain unshipping when dropping down to the small ring.

The medium cage mech should work, but it wil help if your bike has a longer mech hanger - 30mm ideal.

I have a bike with a 26/39/50 - 11-28 set up, 27mm drop hanger, using a Campag med mech. It works fine.

[aoxomoxoa]

Thanks for all the input. I've ordered a 24T inner ring and will see how well it works with the existing set-up before I embark on any additional expense and hassle.