Team THREE 4est

I am trying to upgrade my wife's road bike rear cassette from 27t to 34t max teeth. I will need new derailleur cages (long). I cannot find them anywhere online. Can I use long cages from another Shimano derailleur (Deore or XT)? Will those SGS cages fit and function on the Dura Ace?

Advice please.

Polaris OBark

Unfortunately, they aren't interchangeable. Maybe Di2 Ultegra medium cage might work, if you can find a dead one as a donor. Dura Ace never seems to go up past 28 or so. They never made the longer cage.

The most cost-effective work-around might be to get a Wolf Tooth derailleur hanger extender.

https://www.wolftoothcomponents.com/products/roadlink

The nuclear option is to get a Di2 XT rear derailleur. I am almost certain this will also force you to get an XT front derailleur. But the good news is Di2 lets you use that with your extant road shifters.

veganbikes

Only problem with an XT front derailleur is they are designed for mountain bikes so they don't usually work so well with road stuff due to mounting and such.

Again without knowing which derailleur it is, it is tough to really tell. Actual 1st gen Di2 is not compatible with any newer stuff at least not easily (I think someone might have made some e-tube wire converters at some point but I cannot remember for sure) The Wolftooth Road Link might be just the ticket or if you can find a longer cage road Di2 derailleur that is compatible with your system go for that. I dislike Dura-Ace partially for that reason it is pure race stuff (and it also usually doesn't quite look as good as Ultegra ATMO...except maybe in the 9 speed era when everything kinda was meh) It is excellent equipment and works really well at a decent weight but the lack of versatility is always a bummer.

FWIW I have a RoadLink on a 7400 RD running 6 speed and it seems to work fairly well. They don't recommend it but it seems to do the trick. Is better designed for the modern stuff.

Polaris OBark

Just to clarify, I think even if an XT(R) Di2 conversion worked flawlessly, it would be cost-prohibitive.

The Wolf-Tooth solution is about $20, so I would recommend trying that first.

A GRX 46/30T crankset (which might also do the trick) is $150.

Team THREE 4est

Would a replacement cage have to be Di2? Are the cages for Di2 different than for the regular derailleur? I am not changing the whole derailleur, to XT or anything else. If I can't change for longer cages, I won't pursue the upgrade.

Also, would a 9 or 11-speed cage work? One would think that the mounting holes would be the same. Does Shimano make a completely different cage system for each derailleur? I had thought to buy a Deore long cage and see if the cage would transfer. No?

veganbikes

Again what derailleur do you have, what is the model number?

Shimano will generally do different cages for different derailleurs but knowing exactly which one you have could better help determine what era of derailleur cage you might look at.

You can try whatever you want to try but that could get expensive or you have extra derailleurs in the bin for future projects.

TerryDi2C

Perhaps the easier question is:

Is your wife's bike a 10-speed Di2 bike, or 11-speed?
Feel free to post a picture too, if that's easier

70sSanO

There is merit in identifying the exact RD by pn. While cage swaps between newer road and mtb cages RD are probably rare, and there is good chance no one here can help, but without it the basic answer is no.

With the pn you can at least Google it for a swap. There are all sorts of hacks out there that might help you.

The only other recourse is to pull it apart and try to visually match to a long cage, maybe ebay, order it and see if it works.

And if you get it to work you can ask the next person the pn because you have a one-off success story.

John

TerryDi2C

Indeed, which is why I asked whether it is 10-speed (FD-7970), or 11-speed (FD-9070) ;-)

When people say "first generation dura-ace" they sometimes forget that 7970 existed too

cxwrench

The road link allows the upper pulley to clear a larger-than-spec'd big cog but doesn't magically make the pulley cage longer to wrap the extra chain needed. Not a good solution.

Polaris OBark

Yeah, it looks like they pre-suppose a GS cage.

kek

https://fitwerx.com/k-edge-long-cage...r-and-quicker/

sch

K Edge was the only extended range solution back 10-11 yrs ago when the Di2 was mostly for racing
types who can average > 20mph with ease on a 60 mile 3000' elevation change ride and then mow
the yard, wash the cars after an oil change and tire rotation after the ride. Then Shimano started
making wider range Di2 derailleurs. The K edge was of most interest to tandem riders who need
a wide range. FWIW K edge was very proud of their conversion, I am a bit surprised it still exists
considering the range of Di2 now available for chainrings down to 30t (28t feasible) and cassettes of 42t.

squirtdad

remember that the length of the derailler cage does not directly impact the max rear cogs a derailler can handle. derailler cage length impacts the amount of wrap a derailler can handle.

bamboobike4

I once grafted a 600EX long cage onto a DA7400, but that's old stuff (and it worked smoothly on a 12-28 6-speed freewheel)

I paired.a DA7700 GS RD with a Wolftooth Roadllink and an 11-34 9-sp cassette and a 53/38 crankset, successfully, but the minute or so I was in the lowest 38/34 was not silent. I had the chain biased to not flop on small/small, therefore it was too tight on small/biggest. Were I do do it over, I'd add two links and stay off of the small/small.

I would not have tried them, at the time, on a carbon frame or even aluminum.

Snce then, I've used the Wolftooth and it works fine on numerous setups. I'd not guarantee results, but for $21.95, it was worth a shot or two.

I'm currently running DA9000 and DA9100 RD's with 34T cassettes (both compact 50/34 cranksets and full 53/39 cranksets).
That's 39T and 37T chain wrap.

I'm running Di2 Ultegra GS (med cage) RD with a Wolftooth and an 11-36T cassette, compact crankset. That's 41T chain wrap.
I'm running R8000 GS RD with a Roadlink (DM) and a 36T cassette, compact crankset. Same 41T chain wrap.

The older version works on the older Di2, and goes between the RD and the dropout.
The newer version replaces the part of the RD that bolts into the dropout.
There are many copies coming out of China, but I've not tried any.
It's a very simple concept: pivoting mounting points, 22mm extension between them.
I have no idea why they settled on 22mm, but my guess is that the longest they feel OK selling.

There are no guarantees, only anecdotal evidence, which I've provided above.
They don't increase chain wrap, so you need to be careful on your chain length.
It will be too tight on one end, and possible be too loose on the other, so you can choose to "bias" it.

The Wolftooth extends the RD distance from the axle, but It does not lengthen the cage.

If at all possible, you want to lengthen the cage, but in many cases, that's not possible. I'd take good looks at RD's to see if the cages match up. I know there are aftermarket cages.

I did this for Shimano only, and am confident that older Campy on steel bikes will work fine.
Due to the price of failure on Campy, I've avoided it.

For SRAM, I simply bought a clutched X.9 RD and swapped it in for my Red (10sp) RD and went big on the cassette (11-32).
It was fine. My other SRAM is 1x11 10-42 and simply not part of this conversation.

Good luck, PM me and I can be clearer, but there is never a guarantee. I'm in the same boat with older 2x10 Di2 on a newer bike, and I'm going to try it with an 11-32 and a Roadlink.

Team THREE 4est

Let me know how the 11-32/Roadlink works.

The crankset is an Ultegra, with a 53/39. It is not a compact. I can find the GS cage (rear/inner), but not the front/outer. Don't know why...

I can find a Deore with a long cage, but it is a 9-speed. How does a metal frame know how many times (or how far per) it is shifted?

Polaris OBark

Replacing the crank with a GRX 46/30T might be the most straightforward approach, and would immediately give a substantial advantage in terms of lower gearing for a $150 investment. I was able to make it work with my Ultegra Di2 front derailleur, it might work in your case, too. Then, if you need the Wolftooth, you will have the advantage of more forgiving chain wrap.

Polaris OBark

I'm doing the same, but with no Wolftooth. I also have a 46/30T GRX crankset, which helps, and despite claims to the contrary, works quite well with my otherwise Di2 Ultegra drivertrain.

veganbikes

Yeah if not compact go to a compact or sub-compact set up. That is probably the biggest reason she is struggling. Unless you are racing or a really strong rider you are probably better off sticking with a compact crank. Plus if you are trying to get a lower gearing in the back it will help more with your max chain wrap.

Team THREE 4est

It's a 7970 RD.

70sSanO

K-Edge used to make an aftermarket long cage for that derailleur. It is no longer available, but you might want to contact them and make sure.

They may also know if there are any options such as a 6770 GS.

John

Team THREE 4est

Shimano till makes a long cage 10-speed 105 (5701), Deore (M5120), or Tiagra (4700). Would any of these cages bolt on? How different are the cage mounts between models? Will XT/XTR in 10-speed work?

Team THREE 4est

Shimano has a 10-speed medium cage in Ultegra (RX-800). Would that cage bolt on?

cxwrench

Nevermind.

KCT1986

The RX-800 appears to have a different attachment design for the cage. Most of the 'Shadow' style looks to have a different method of cage attachment.

See the attached. RD-6800 seems similar also. Note the cage bolt attaches from the rear through a hollow axle. Many of the older models uses a solid axle and is held on with a thin screw through the side of the main body. Don't know for sure if this would work, but appears to be similar. Never tried this personally.

Good luck. Let us know what you find.