rahum

Hey folks,

I want to replace the cage on my RD-6600-SS (short) derailleur to turn it into the "long" GS cage.

I am having a hard time finding the actual parts for sale without buying a completely new derailleur.

Can anybody help me identify the part(s) I'll need?

Thanks!

cpach

Part numbers are here: https://si.shimano.com/api/publish/s...6600-2358A.pdf .
There is a nearly zero percent chance you will find the parts. 6600 is like a decade old. You may be able to hack it with other parts or off of scavenged parts if you have access to a large number of used parts.
If you really just need slightly more chain capacity, and not particularly larger max cog, buy something like a modern 9 speed Sora derailleur, it'll index fine with your 10 speed drivetrain. Or if you want to use a significantly larger cassette just use a 9 speed Shimano MTB derailleur.

dedhed

Your chances of finding the parts as separate items is slim to none. Best bets are expanding your scope to include 6500, 6700, and 5XXX series 105 as well as 9 spd or less mountain.

HillRider

Not that difficult. Shimano RD-5700-GS and RD-6700-GS are still available and will allow a 30T largest cogs with a triple crank and 32T with a double. They will really allow a 32T cog with a triple if you are willing to exceed their published wrap capacity and avoid small-small.

cxwrench

Just in case anyone (other than the OP) is confused, GS is not 'long', it's medium, SGS is long.

masi61

It might be worth looking into a KCNC oversized pulley cage. I’m checking eBay for ones compatible with 6600.

70sSanO

Shimano never made an RD-6600-SGS. It was either SS or GS. OP will never find one. Not sure what other SGS cages will fit.

One of my favorite long cage rear derailleurs is an XT-750. If you can find a good one on eBay, it will work quite well with whatever chainring/cassette setup you end up with.

John

rahum

My understanding is that I can run up to a 32T cog with the RD-6600-GS if I'm using the Wolftooth Roadlink.

Davet

oversized pulleys won’t fit in the stock derailleur cages, there’s not enough room when the chain is installed.

cxwrench

Never said Shimano did make one. I was just letting the OP know that his derailleur was a 'long' cage but it's a medium, and explaining the SS, GS, and SGS descriptions in general.

alcjphil

Buying and finding the required parts would get you very close to the price of a suitable Mountain bike rear derailleur which would work much better

cxwrench

You can get the derailleur to shift with a 32t cog but the Roadlink doesn't magically make the cage longer so it will never have the capacity to wrap the extra chain you'll need. Says so right on the Wolftooth site. This has been discussed so many times...

70sSanO

As already stated chain wrap has nothing to do with how large of a max cog a person runs. It has everything to do with how much excess chain can be stored up when running in the small chainring and the 1st and maybe 2nd, 3rd cog position. Traditionally touring rear derailleurs could accommodate a larger max cog and had more capacity (chain wrap) to run triple cranksets than traditional race rear derailleurs.

My main road bike is setup with a triple and a traditional touring 14-34 cassette. I'm running an XTR 910 rear derailleur that has a capacity of 33t. My capacity is 38t. I've never had an issue because I've never shifted to the 30/14 small-small combination. I've never had an occasion nor come close because I'm only using the 30t chainring when I'm pushed to on some climbs. On a number of rides I never use the 30t. It is just that extra low option and gets limited use.

However, on my mountain bikes I'm running a 2x and I use every gear combination. I added a Roadlink to run a 40t. It was primarily to use with the 24t chainring on any climb that I was struggling on before. What I found is that I use it more with my my 34t chainring and keeps me from having to shift chainrings for a short section. I'm really quite pleased. But, I don't have a capacity issue with the Roadlink since I'm running an SGS so small/small is never an issue. Occasional chainslap does occur, which is another subject.

In my experience everything depends on how the bike gearing is setup and used. For me it depends on whether it is a double where the inner chainring is used more extensively or triple where it is used sparingly.

The OP does need to determine how he intends to ride his setup.

John

cpach

For what it's worth I'd rather run a 9 sp Deore derailleur with a 10 speed road drivetrain than a 10sp road derailleur and a wolflink, assuming you want larger than a 32t (in which case, yeah, 5700-GS-A or honestly a current Sora derailleur would work).

vautrain

Sorry for replying to an old thread here, but I've been running an Ultegra 6600 GS rear derailleur with an 11-32 cassette for years with no problems and no derailleur hanger extender. Crankset is an Ultegra 6750 50/34 compact.

delbiker1 

The gs is the long cage, it’s designed for 32 tooth at least. I have running a 6600 shortcage with an 11-36, matched with 6750 crank switched to 46/34. Shifters are 4600 and shifting is spot on.

vautrain

From my reading, that's a matter of some debate about whether the GS cage can indeed handle (on paper or in reality) a larger rear cog than the short cage. I don't have the tech doc in front of me, but according to third parties, it lists the same max rear cog for both SS and GS of (obviously false) 27T.

However, I'm quite intrigued by your setup. I didn't imagine even the 6600 GS derailleur could handle a larger rear cog than 34T. That's great to hear it may be able to go further. I happen to have an NOS 6600 GS on my desk as I'm typing this, and I think I may go ahead and use it for a project I am working on. I happen to think it's one of the best looking among the modern Shimano rear derailleurs, too.