New chain and rear derailleur help

Kanya

Hey

Hopefully someone can help. I have a Boardman Pro HT 2009, and recently the chain snapped.

I got a new SRAM replacement chain (9 speed) and adjusted the length to the correct size etc. The kit on the bike is SRAM X0

However, I do not think the chain looks correct through the rear derailleur although I'm sure it's on correctly (from what I can see via google and youtube etc)

The chain now rubs/grinds against itself (see pics below) when in a certain gear ratio - bike's not been ridden like this, it's hung on wall in garage until I can rectify it.

Also seems to have a lot of rub on front derailleur and the chain changes gear in a very clunky manner - it changes, but not smoothly. Never changed a chain before so any suggestions..?

There's no tight links nor is it the wrong length (hopefully, I did as per all instructions I came across).

Any help would be appreciated!!

Pic below shows the chain touching and grinding against itself:



This pic below shows how I have fed the chain through derailleur in case it's incorrect.

Anonymous

Looks to me like a short cage rear mech, with a triple chainring setup at the front. Won't work.
And, apart from that, are you aware you shouldn't be using small sprocket/small chainring, or large sprocket, large chainring combos?

Andy B

The chain is still too long, remove a full set of links & try again.

Oh, clean your jockey wheels and any other parts coated in that brown muddy oil, not much point in fitting a new chain for it to get coated in that brown grinding paste.

Anonymous

I don't understand how the rear derailleur is so dirty if it's new.

Andy B

yeehaamcgee wrote:

I don't understand how the rear derailleur is so dirty if it's new.

I don't think it is new, only the chain is new from what the OP has written.

Still needs a good clean though

The Rookie

Agreed, take the chain off, clean the jockey wheels, refit chain and size according to all the guides which means that wrapped around the 2 big wheels it should be almost straight on the return (lower) side.

Simon

Kanya

yeehaamcgee wrote:

Looks to me like a short cage rear mech, with a triple chainring setup at the front. Won't work.
And, apart from that, are you aware you shouldn't be using small sprocket/small chainring, or large sprocket, large chainring combos?

Regarding the short cage rear mech and triple chainring setup - this is the standard set up, as I have replaced nothing except the chain - surely replacing the chain should still work as long as the length is correct?

The bike's going to be completely cleaned, the sludge was from using a wet lube and mud. Chain will be properly cleaned and oiled before use - I just wanted to get the thing on and make sure I got the set up correct.

As for cross gearing - yeah I know

Kanya

Ahh so general consensus is that it's still too long. I sized by using large "wheels" then added two links over where the chain met.

Yeah the derailleur isn't new, just the chain.

Andy B

If you still have the old chain you can use that as a guide to the right length, bear in mind any links that are missing from the old chain though

Kanya

Yeah I'll go grab the old chain and whip the new one off again and compare the two. Was wary of making the chain too short as that would have been a mare...!

Thank you all for your help, really appreciated the quick responses :-)

oh and I'll get that derailleur sparkling...I promise ha ha ha

Cheers!

cooldad

Don't measure the new chain against the old as it will be a bit stretched. You could count the links though.
But measure big/big and add one link.

The Rookie

Your top pic is the give away, mech should never be wrapped up the back like that.

Simon

Kanya

Ah I did the following:

Equal length + 2 links + master link as per this video http://www.youtube.com/watch?v=sSl8F6ZLLFg (it shows at 3mins 10 secs)

So should it be exact length + master link or exact length + 1 link + master links?

Anonymous

When you measured the chain, you did exclude the rear mech, right? just the chain over large-large sprocket and chainring.

Anonymous

Andy B wrote:

yeehaamcgee wrote:

I don't understand how the rear derailleur is so dirty if it's new.

I don't think it is new, only the chain is new from what the OP has written.

Ah, I was misled by....

New chain and rear derailleur help

I thought he meant he had a new chain and rear mech, and needed help.

Kanya

yeehaamcgee wrote:

When you measured the chain, you did exclude the rear mech, right? just the chain over large-large sprocket and chainring.

Yea, didn't take the new chain through the derailleur when sizing, just over the two large sprocket/chainring then used exact length plus two links plus the power link/master link

Kanya

yeehaamcgee wrote:

Andy B wrote:

yeehaamcgee wrote:

I don't understand how the rear derailleur is so dirty if it's new.

I don't think it is new, only the chain is new from what the OP has written.

Ah, I was misled by....

New chain and rear derailleur help

I thought he meant he had a new chain and rear mech, and needed help.

You have a point - it does read that way sorry!

Anonymous

Ah, the masterlink counts as half a link, so that should be included in your measurement. Inner plates+outer plates = 1 link.
Powerlink/Masterlink = 1/2 link.

Kanya

Sooo just so I am clear (lol)

I'll remove the chain and powerlinks.

Chain should be as follows:

Exact length plus one with powerlinks.

cooldad

Yes