I recently bought used Ultegra RD-6600 long cage rear derailleur. Anyone know what is the largest capacity or gear range this will handle in a cassette? My bike currently has 12-28, which I know will not be a problem, but I'm wondering if it could handle an 11-32 or 11-34 cassette? Thanks.

Shimano tech docs (here) show a 27T maximum sprocket for both short and long cage. As with all Shimano RDs, this is conservative.

I would guess that 34T is pushing it but I suspect that 32T could work. Maybe someone else with this RD can chime in

13-34t + Deore RD has many years of use behind it already .. 48-36-22t on the crank end..


Isn't long cage for a road RD, a medium for a MTB RD? how far are the pulleys apart?


1 chainring up front . simplifies the chain wrap job in back .. screwing in that B screw is also there to use..

In most cases where a derailleur exists in both long and short cage versions, the rear sprocket capacity is the same. That's because the same basic is used, with the only difference being the length of the lower half of the cage. So take up capacity is increased, but sprocket clearance isn't.

However, I agree that there is fudge room on the stated capacities, so you can certainly go to 30t, and maybe larger yet if careful about chain length.

Chain length is important because the upper pulley drops as the cage rotates, so the chain length affects the sprocket clearance.

If I were going to a 34t cassette, I would consider a derailleur made for that, though if I had something already, I'd give it a shot.

I've got a Shimano Ultegra long cage rear derailleur on my tandem and I'm running a 11-32 tooth cassette with out any problems. Even though the specs say a 28 tooth cassette is the largest it will take, that's being very conservative, many folks are running larger cassettes.

I think it can handle a 34 tooth sprocket with some modifications. The chain will need to be lengthened and the "B" adjusting screw might have to be reversed giving you additional adjustment capabilities.

Hopefully others that have made this modification will chime in.

A 32 max cassette cog should be fine more my purposes. The bike currently has a Shimano 50-34 compact double crankset, but I am switching it to a 105 triple with 52-39-30 chainrings. I also picked up an Ultegra triple FD. I may be just fine with the existing 12-28 cassette but would like to know my options if I desire more low-end gearing. This is a touring bike (Bob Jackson) that I am primarily using for commuting. I have another touring bike with a Sugino triple crankset and 11-34 cassette, and it's my preferred bike for loaded touring.

tarwheel, Maybe this will help:
[TABLE]
[TR]
[TD][/TD]
[TH="bgcolor: yellow"]30[/TH]
[TD="align: center"]13.3 %[/TD]
[TH="bgcolor: yellow"]34[/TH]
[/TR]
[TR]
[TH="bgcolor: yellow"]28[/TH]
[TH="bgcolor: white"]29.1[/TH]
[TD][/TD]
[TH="bgcolor: white"]33.0[/TH]
[/TR]
[TR]
[TD="align: center"]7.1 %[/TD]
[/TR]
[TR]
[TH="bgcolor: yellow"]30[/TH]
[TH="bgcolor: white"]27.2[/TH]
[TD][/TD]
[TH="bgcolor: white"]30.8[/TH]
[/TR]
[TR]
[TD="align: center"]6.7 %[/TD]
[/TR]
[TR]
[TH="bgcolor: yellow"]32[/TH]
[TH="bgcolor: white"]25.5[/TH]
[TD][/TD]
[TH="bgcolor: white"]28.9[/TH]
[/TR]
[TR]
[TD="align: center"]6.3 %[/TD]
[/TR]
[TR]
[TH="bgcolor: yellow"]34[/TH]
[TH="bgcolor: white"]24.0[/TH]
[TD][/TD]
[TH="bgcolor: white"]27.2[/TH]
[/TR]
[/TABLE]

Brad

Thanks for the gearing chart, Brad. The reason for the change is that I previously had a triple on the Bob Jackson, which I moved to Soma Saga when I got it. I then installed the compact double on the BJ because I already had it. However, I'm finding that I prefer riding the BJ with a triple, even if not using it for loaded touring. I like the gearing selection better as well as the low end.

I've used this rd with a 32 but I think it depends on the configuration of the derailleur hanger. I've encountered other bikes where I had to go to a mtb rd to use a 32.

Beat me to it. All RD hangars are not alike, and some of them can't even deal with the longer B-screw trick.
I think you have a good chance of it working just fine, however.

If it were my bike, and I needed a gear a little south of 30", I'd go for that triple with a 12-30T cassette rather than an 11-32T.

tarwheel, Another possible option is to use a 28T granny chain ring with the 12-28 cassette. This will give the same low as a 30-30 and about a 25 GI granny with a 30T cassette cog. This configuration will keep some handy gears in the more often used area of the cassette during your commute.

I think a gearing tinker for my back-up touring bike has been hatched.

Brad