SRAM X9 - What's broke now (pics attached) ?

Beansontoast

[*][*]OK good people of bikeradar, I seem to have inflicted further damage upon my trusty Speccy Pitch Pro 2009.

This time, the lower jockey wheel, complete with chain-in-tow, is happily tucking right up into the cassette when in the higher gears.

If that's not explained that well, take a look at these three pics.
You can clearly see, the higher the gear I am in, the more the rear jockey\mech\ whatever-you-call-it, tucks up into the cartridge.

Has anyone seen this before, and do you know to what extent I can replace individual components on an X9 rear dearilleur?

The Rookie

Perfectly normal, if the chain is starting to rub then either the chain is too long or the mech has too low a capacity.

How many front chainrings are you running? If it's 1 the chain is too long anyway.

Beansontoast

3 at the front.

What do you mean by "the mech has too low a capacity"?

This is the original X9. I don't remember seeing the higher gears tucking up this high, hence the post.
However, I did replace the chain a few weeks ago.

The Rookie

Did you size the new chain correctly? How did you do it.

On the small ring at the front and small sprocket at the back (which of course you shouldn't ride in) that is normal maybe you only looked at it when in a bigger ring at the front, which as that means more chain wrapped, will pull the mech forward into roughly the position in your middle pic.

keef66

Your chain looks miles too long.

Beansontoast

Yeah .... deffo sounding like I stuffed up measuring the chain.

From memory, I found some guide online, which went on about letting all your air out the rear shock, and when everything is compressed, wrap round largest chainring, and largest sprocket, add two links + master link.

Does that sound right? Maybe I'd been on the turps. I best go and check !

cooldad

Nope, two links maybe, but including the master link. Or maybe one link - depends on the chain growth, if any.

cooldad

And leaving out the mech.

keef66

On my road bike I use big ring / big sprocket / not through the mech then add a link (inner plus outer which in my case is the missing link)

nicklouse

Beansontoast wrote:

From memory, I found some guide online, which went on about letting all your air out the rear shock, and when everything is compressed, wrap round largest chainring, and largest sprocket, !

this is only if you have chain grow with suspension compression.

if Like some designs the chainstay length can grow to a certain amount before reducing again. in that case the length should be set at the point where the chainstay length is greatest.

Beansontoast

Ok. Soz everyone, but the chain length is spot on. If anything I'm a link short. Definitely not too long.

So, there is something else wrong with this derailleur. From other research, there is some kind of embedded spring-type mechanism inside the sealed black plastic section of the mech. I am trying to find if that is replaceable or not.

The Rookie

Your photo show nothing wrong with it, what makes you think there is?

In that photo above, you need to pull the chain tight, you can clearly see a big sag on the top run.

Beansontoast

Forget about the chain length. It's spot-on.

Getting back to the original point of the entire post - the mech is near-enough tucking right up into the cartridge in the higher gears (and we have clearly established the chain length is good).

The Rookie

And that is how a mech often looks in small small when it's using its maximum capacity, as long as the chain is running freely what is the issue?

JGTR

So how do you know the chain is the correct length?????

JBA

Going back to the original post and photos: Which chainring was the chain on when you took those photos?

If you were on the large or middle then that chain is too long.
If you were on the granny then it looks normal as you should never cross-chain like that.

Did you compare the length of the new chain against your old one?