Rear Derailleaur Extender query

[bobdaspider]

I'm using a 9 speed Campy setup but have installed a relatively new rear derailleur (medium sized cage) which is 9 / 10 speed compatible. Am using 52 x 39 chainrings and a 13 x 25 cassette. Unfortunately, the chain rubs against part of the derailleur when using the lowest gears 1 and 2. The derailleur doesn't have a B limiter screw so am unable to adjust this, and trying to source a 9 speed compatible large sized cage campy rear derailleur at a reasonable price is going to be tough. So, was interested to learn about the rear derailleur extenders - which fit onto the frame and then the derailleur fits onto the extender thereby converting a medium-sized derailleur to a large one. These extenders are available on Amazon but will have to ensure that it fits a road bike, as most are advertised for mountain bikes. If anyone has any info or experience with using a rear derailleur extender, I'd be pleased to hear it. It may be the solution for allow me to use all my gears - including 1 and 2.

 

[Big John]

Are we talking about a Wolf Tooth extender? I'm definitely not an expert when it comes to Campag stuff but I'd be surprised if anyone would need a wolf tooth for the set up you have. A 52/39 chainset and a 13/25 cassette I would have thought was bog standard for a road bike. I had pretty much the same set up for years and only had a normal rear mech and never had cause to fit a wolf tooth. What exactly is rubbing? I could understand something possibly rubbing on the front mech but not the rear.if the chain moves onto all the sprockets on the back without the chain fouling on one of the sprockets then there's no need for an extender IMO. A wolf tooth I believe is used to help the rear mech cope with the larger sprockets seen on 1x setups and 25 isn't that big by today's standards.

 

[Sharky]

Have you got too many links on the chain? A shorter chain should pull the RD down and away from the sprockets, if that is where it is rubbing.

 

[Ajax Bay]

9 speed Campy setup . . . rear derailleur (medium sized cage) . . 52 x 39 chainrings and a 13 x 25 cassette. Unfortunately, the chain rubs against part of the derailleur when using the lowest gears 1 and 2.

Which part of the RD does the chain rub on in two largest sprockets? The side of the cage?
Let's have a side view image of the chain (complete) in large/large.
Bonus: one in large/small.
Capacity and largest sprocket tooth count well in spec.

 

[T4tomo]

I'm using a 9 speed Campy setup but have installed a relatively new rear derailleur (medium sized cage) which is 9 / 10 speed compatible. Am using 52 x 39 chainrings and a 13 x 25 cassette. Unfortunately, the chain rubs against part of the derailleur when using the lowest gears 1 and 2. The derailleur doesn't have a B limiter screw so am unable to adjust this, and trying to source a 9 speed compatible large sized cage campy rear derailleur at a reasonable price is going to be tough. So, was interested to learn about the rear derailleur extenders - which fit onto the frame and then the derailleur fits onto the extender thereby converting a medium-sized derailleur to a large one. These extenders are available on Amazon but will have to ensure that it fits a road bike, as most are advertised for mountain bikes. If anyone has any info or experience with using a rear derailleur extender, I'd be pleased to hear it. It may be the solution for allow me to use all my gears - including 1 and 2.

you don't need a large cage Rd for 52/39 13-25 set up. So whatever the problem is, its not derailleur capacity.
I suspect as others have said, its just too long a chain. photos will help....

 

[bobdaspider]

Thanks guys for your comments and feedback - I attach a pic of the rear derailleur showing the cassette in contact with the cogs of the rear derailleur - this means that I'm currently unable to use gears 1 and 2 ( the lowest gears / biggest sprockets in cassette). If it's a case of shortening the chain, then great but I do remember the LBS talking about clearance issues re RD / chain / gear setup (i.e. 53 x 39 / 13 x 25) etc.

 

[Ajax Bay]

Thanks for the pics.
If the chain was on the 53t for those images, certain the chain's too long.
https://i.ibb.co/qsyvJpZ/Screen-Shot-2019-07-29-at-2-52-26-PM.png
I asked: "Let's have a side view image of the chain (complete) in large/large.
"Bonus: one in (Edit) small/small." Please, and see below.
"the chain rubs against part of the derailleur when using the lowest gears 1 and 2." Which part?
With the cable unclamped, can you manually push the RD/cage across underneath the two largest sprockets?
https://support.campagnolo.com/media/files/035_259_Technical manual - Mechanical units rear derailleur - Campagnolo_Rev03_02_23_EN.pdf
See Figure 10 and screw 'H' which has the function of dropping the guide pulley wheel down (if that's the issue).

 

[bobdaspider]

Thanks for the pics.
If the chain was on the 53t for those images, certain the chain's too long.
https://i.ibb.co/qsyvJpZ/Screen-Shot-2019-07-29-at-2-52-26-PM.png
I asked: "Let's have a side view image of the chain (complete) in large/large.
"Bonus: one in (Edit) small/small." Please, and see below.
"the chain rubs against part of the derailleur when using the lowest gears 1 and 2." Which part?
With the cable unclamped, can you manually push the RD/cage across underneath the two largest sprockets?
https://support.campagnolo.com/media/files/035_259_Technical manual - Mechanical units rear derailleur - Campagnolo_Rev03_02_23_EN.pdf
See Figure 10 and screw 'H' which has the function of dropping the guide pulley wheel down (if that's the issue).
View attachment 729520

AB - thanks for this - will put my bike on the turbo tomorrow and another pic re above diagram. The pics shown before were in the small ring and on the second lowest (second largest inside sprocket). Thanks again.

 

[Ajax Bay]

Waiting on answer to this: "the chain rubs against part of the derailleur when using the lowest gears 1 and 2." Which part?

 

[T4tomo]

Waiting on answer to this: "the chain rubs against part of the derailleur when using the lowest gears 1 and 2." Which part?

Sometimes you wonder if people take the worst photo possible and provide the slimmest amount of info they can get away with. Maybe there is a "see how long you can spin out a thread on cyclechat with a basic issue" forum somewhere 🤣

Apols to the OAP if you are genuine. Decent photo on big big and small small please.

 

[Ajax Bay]

Even if they aren't a 'genuine' OAP!

 

[bobdaspider]

Guys - finally we have additional pics with chain in big and small ring and top and lowest gears at the back. Re the issue of cassette touching the jockey wheels of the rear derailleur, I'd be wanting to use gears 1 and 2 on the small ring - i.e. to make things easier when going up steeper hills. At the moment, the lowest gear I dare use is gear 3.

 

[Ajax Bay]

Thank you, however.
I asked: "Let's have a side view image of the chain (complete) in large/large.
"Bonus: one in (Edit) small/small." Please.
Your images do not meet this simple spec. If you are concerned about pushing the chain onto the largest sprocket, at least get it on the second largest.
Have you adjusted (in/out) what is normally known as the 'b' screw but Campagnolo has "H" screws and they work in reverse? To drop the pulley wheel down.
Please also, as a special treat, check the number of teeth on that large sprocket, which you say is 25.

 

[T4tomo]

Guys - finally we have additional pics with chain in big and small ring and top and lowest gears at the back. Re the issue of cassette touching the jockey wheels of the rear derailleur, I'd be wanting to use gears 1 and 2 on the small ring - i.e. to make things easier when going up steeper hills. At the moment, the lowest gear I dare use is gear 3.

@bobdaspider is a few strands short of a web

 

[Paulus]

I would go along with those who have said that the chain is a little too long, by at least one link, so is not pulling the RD down enough to clear the cassette.