Is this the Shimano short or medium cage derailleur?

[Mark1978]

Can't find any identifying marks on it to work it out. I want to change the 11-28 to an 11-32 for a trip to the peak district in a few weeks and want to know if i'll need to change the derailleur.

Cheers

 

[raleighnut]

That cable end.

Look at the number stamped on it, GS is medium cage, but TBH it looks like a standard to me.

 

[Tangoup51]

If I was you i'd buy the 32 first and try it on for size, strictly eye-balling it I feel like it would just go on at a very tight pinch, but that's no in-depth opinion.

 

[Mark1978]

yeah, must sort out that cable end !! I'll have another look to see if i can find the number on it.

 

[Mark1978]

Just hunted around and it's an RD. How i didnt notice that stamp before i'll never know.

I guess that means it's standard and from what i've read the 32 wont work with it.

Edit : its RD 6800 not RG!!

 

[raleighnut]

 

[Nigelnaturist]

Judging from the chain links between top and bottom jockey wheels I would say its an short cage (S.S.) RD stands for rear derailleur, I have at least one extra full link on my 105 RD5700

 

[Nigelnaturist]

View attachment 348401

I was just looking at that

 

[Mark1978]

One other question, if i switch to the medium cage and a 32, will the chain length be ok or will i need to increase it?

 

[Winnershsaint]

I am no bike mechanic, but from what I've been led to believe the derailleur bodies are the same in Ultegra (they certainly are in 6870 Di2) it is only the cages that are different in size. The mech cage will need to be the medium rather than the short. (That's GS rather than SS) Fortunately the cage parts can be sourced through SJS Cycles.
https://www.sjscycles.co.uk/gear-spares/shimano-ultegra-rd6800-inner-plate-gs-type-y5yc25000/
https://www.sjscycles.co.uk/gear-sp...er-plate-plate-stopper-pin-gs-type-y5yc98080/.
At £25 for the parts inc p&p all you need is a friendly bike mechanic to complete the conversion, if like me you only sit on the bike and pedal it. I've ordered mine today for my trip to the Alps in June. I've also gone for a compact chainrings instead of the 52-36 set up I currently have. They're Rotor not Shimano though.

 

[Ajax Bay]

if i switch to the medium cage and a 32, will the chain length be ok or will i need to increase it?

If you're putting a new cassette on (32t max) and assuming the chain is the correct length currently (in large/large cage should be 4 o'clock or later), the chain will need to be probably one link and maybe 2 (inches) longer. Best to determine length required from first principles.
If you're putting a new cassette it's sensible to put on a new chain anyway. Hold on to the old one (measure it while it's off the bike) and when you put the 28t max cassette back on, on return from the Peak District, replace the old chain too (holding on to the 'new' one as its replacement, in due course).

 

[Tangoup51]

One other question, if i switch to the medium cage and a 32, will the chain length be ok or will i need to increase it?

In all honesty the suggestions above are preparing you to set up your gearing for long-term uses. Not for a short few rides around the Peak district.

Reality is; you will get away with doing very little other than swapping your cassette.

Swapping your RD may be necessary, but as I say you may not have to do it. Particularly in short-term cases you should be able to get away with keeping the same chain too, just don't plan on running this set up long term, but there's little reason I'd suspect for you to having to swap all of these things around for one particular occasion. Swap your cassette and go from there!

 

[Ajax Bay]

Reality is; you will get away with doing very little other than swapping your cassette.

I don't think 'will get away' is right. May get away. But large to large with a 32t where the chain was the right length for 28t may well result in expensive drive train breakage or just not being able to change up to the 32t, which is the whole purpose of the OP's question. "Will get away" is not sensible advice. By all means fit the 32t max cassette and see if it'll work with the current chain (length), but don't plan on it.

 

[Tangoup51]

I don't think 'will get away' is right. May get away. But large to large with a 32t where the chain was the right length for 28t may well result in expensive drive train breakage or just not being able to change up to the 32t, which is the whole purpose of the OP's question. "Will get away" is not sensible advice. By all means fit the 32t max cassette and see if it'll work with the current chain (length), but don't plan on it.

IT may cause those issues; I already made my warning. This should not stop him atleast trying to see if it'd work by just swapping the cassette over and tuning his current derailleur, I've had success doing this very thing for a Rear derailleur / chain that wasn't designed to go up to 34T. But I indeed got it working and it lasted me long enough before I swapped back, and no damage took place.

Besides, all this swapping over is alot of scare-talk and money-waste for very little reason, the OP isn't going to be using this set up for presumably very long; the worst case scenario is you just work your RD a bit harder than normal for the next few days! I Hardly Think You're Going to Break any Part of your Drive Chain, especially if you can get this working on a bikestand smoothly, As I maintain, Swap your cassette over and go from there, if there's something that simply won't go into place with any appropriate adjustment THEN you need to replace it.

There's no sense in replacing things without giving them a chance to work.

 

[Mark1978]

In all honesty the suggestions above are preparing you to set up your gearing for long-term uses. Not for a short few rides around the Peak district.

Reality is; you will get away with doing very little other than swapping your cassette.

Swapping your RD may be necessary, but as I say you may not have to do it. Particularly in short-term cases you should be able to get away with keeping the same chain too, just don't plan on running this set up long term, but there's little reason I'd suspect for you to having to swap all of these things around for one particular occasion. Swap your cassette and go from there!

For the sake of 60 quid id rather do the derailleur and chain too and not be constantly worrying about the drivetrain while im in the middle of a 100 miler in the peaks.