Chain length - geared

That pic is big-big, which you should try not to use. The chain does look a *little *bit too short though

Maybe look into the 'B' screw on the derailleur?

Yikes! - way too short on chain- and you're running a compact too with a sort arm mech (but looks like a 23 largest on rear?) is the OEM set up? (all original bits)

i always set up the chain so that small ring to small cog it's as near as it can to the chain rubbing the outside of the rear mech (too much chain) without actually being there

• the mech rides smoother
  
  

incidentally also:more links = less wear per link so it might last that bit longer, you're much less likely to pull the hanger off in the case of a jam up and it makes an on the road link failure repair easier to deal with and less likely to put you in a position to run too short a chain and rip the mech / hanger (i had to do this recently and didn't have spare links - but got away with one less link on the system even on the big ring to big cog gear)

Have you found out what it was causing the chain to jump then?

When the chain slips is it when you have weight on the pedals, climbing / sprinting, if yes the cassette's worn out, it has been on other bikes with different chains, all of these different chains try to destroy the cassette cogs to their shape, also you will have a number of cogs which you use all of the time these will be worn, bite the bullet and get a new cassette before it destroys your new, very short chain

Another geared chain length query...

I've always used the Big-big combination plus a couple of extra links method to get chain length and this has always worked. however, on my 105 groupset it results in the rear derailleur being pulled forwards quite a bit more. It looks like the chain is too short.

I'm wondering if it's to do with the 105 rear mech being longer? It is the short cage version I think, but looks a bit longer than the Dura Ace one I have on another bike.

I am replacing the drivechain on my road bike.
I am sticking with the same size chain rings 50/34 however for the cassette I am going from a 12/25 to an 11/28 if I measure the new chain against the old, does this mean the new chain needs to be three links longer to accommodate the extra 3 cogs?
Is it as simple as this? Any help would be appreciated as instructions and diagrams confuse me

Cheers

No. Ignore the old chain and start from scratch making sure the new chain is the correct length. Read this for info

D

Cheers
Will have a bash at it see how I get on

I found this calculator based on the Park Tools method

http://www.machinehead-software.co.uk/bike/chain_length/chainlengthcalc.html

Stupid question but before I go off and start chaining stuff, my current cassette is a 12/25 which needs replacing I have an 11/25 kicking about would I need to shorten the changing if I made the change?

No.

If the largest chainring and the largest rear sprocket remain the same, then the length of chain needed is unchanged.

Guys, sorry to bring this back, but I'm at confused.com. I found three different ways to measure the chain and all of them say it's the best way.

1. Small-Small and make sure chain is not touching rear derailleur
   
2. Big-Big +2 links (measuring without derailleur)
   
3. Big ring - small cog - derailleur's jockey wheels vertically lined up.
   
   

I go with #2

^ This.

As described here.