Hi folks, I currently have Ultegra 6800 on my road bike. It has a long cage on the rear derailleur. However, I noticed that all the guys in my riding group seem to have short cages. Is there a benefit to having a short cage vs. a long one?

I prefer the flexibility and ease of sizing the chain with longer cage derailleurs. But if the short cage does what you need it to do, then either is fine.

Sure, but what is the benefit of one vs. the other?

Short-cage derailleurs are very slightly lighter, and in some cases the geometry is optimized better for shifting over tight-range cassettes.

If you're unsure, it's best to err toward longer-cage models. They allow more versatility in drivetrain setup, and the drawbacks of lengthening the cage are very subtle.

Back in my road racing days (mid-late 80s), all road racers road short cage, and long cage was for touring bikes and mountain bikes. Realistically, long cage vs. short cage just determines how much extra chain the derailleur can take up to maintain tension on the chain. Longer cages accommodate a wider gear range better, giving you a more stable chain line and reduced slack. A short cage derailleur weighs a few grams less than a long cage. Some believe that short cage derailleurs have faster, snappier shifting than long cage derailleurs; not sure if there is proof of this. Both may actually shift at the same speed. Short cage derailleurs look more sporty, though.

Also, my cassette is 11-32

Thanks. So if my cassette is 11-32, what do you think? Should I replace or who cares?

If your long cage works fine for the type of riding you do, with that range, keep it. Do you have a single, double, or triple on the front?

My Crank set is a double 50/34. I ride here in Los Angeles, with some climbing and some flats. Generally the group does 30-50 miles per ride. Moderate pacing.

So, look up the specs of the derailleurs.

RD-6800-SS
Capacity 33T
FD Max Difference, 16T
Rear Cassette, Max rear sprocket, 28T

You have: 16T on the FD.
32-11 + 16 = 37T

So, you have about 4 teeth too many on the rear sprocket, both for total capacity, as well as max sprocket size.

Looking at the 6800-GS.,
Total Capacity: 37T,
Low sprocket, rear, 28T to 32T

Sounds just about perfect for your bike.

Looking at the RD-R8000-SS.,
Rear large sprocket, 25T to 30T
Capacity: 35%

RD-R8000-GS,
Rear large sprocket, 28 to 34T
Capacity: 39T

So, you're quite a bit outside the specs for the RD-6800-SS. If you tried it, you'd likely have issues with cross-chaining, depending on how you configured it the chain, and perhaps rubbing on the 32T rear sprocket.

You could drop down to a 28T or smaller rear cassette and get it to work.

The RD-R8000-SS rear derailleur is closer, but you're still just slightly beyond the specs for that. Again, it might work, but you could have issues with cross-chaining, and rubbing on that rear large sprocket.

Of course, the other option is to install the Dura Ace 11/23 rear cassette, and get rid of those pie-plate cassettes.

No matter what the derailleur you put on. the wheel needs to turn at least 1/2 turn before the shift can be completed.

Sure,

But, the closer the jockey wheels are to the cassette, the less chain flex, and theoretically more positive shifting.

This an be achieved through derailleur design, or adjusting the spring tension screws on the derailleurs.

Im not claiming all DRs are exactly equally good. Im pointing out shift speed is limited by the speed of the wheel no matter how good it is. From my experience shifting is dependent on cables, chain and cassette rather than SS vs GS.

The OP must use a long cage to have enough wrap capacity. The idea that the long cage RD doesn't shift as well is nonsense. All the long cage does is take up the additional chain length that necessary to wrap the 50/32, when using the 34T chain ring and the smaller cogs. If the chain was sized for the big/big and a short cage used, the chain would hang loose in several of the smaller cogs.

Depending on the particular model, an 11-32 with standard double exceeds the nominal wrap capacity of the short cage. A compact double 50-34 would need even more.

A long cage can wrap more chain than a short cage, so it can handle a wider gear range than the short cage derailleur. But a short cage derailleur is slightly lighter.

So, you get to pick which benefit you prefer.

Perhaps before talking about derailleurs, one should discuss cassettes.

You have a compact 50/34 front and wide range 11/32 rear.

That gives you a pretty tremendous range of gearing.

50/11 = 4.55 : 1 gearing.
34/32 = 1.06 : 1 gearing.

Are you actually using the entire range?

Would you be better off hitting your hills with say 34/25 (1.36 : 1), and perhaps standing as needed?

The advantages of a smaller cassette is the sprocket spacing.

For 11:25 (CS-6800)
11, 12, 13, 14, 15, 16, 17, 19, 21, 23, 25

For 11:32 (CS-6800)
11, 12, 13, 14, 16, 18, 20, 22, 25, 28, 32

You have some tight gearing in the high gears, but you start skipping a bunch quicker.

It means that if 15T or 17T are the perfect gear for the moment, then you don't have them.

On the other hand, by leaving off the 28/32T, the person with the smaller cassette may struggle more on some of the steeper hills.

A lot depends on your personal fitness, what you're used to, your weight, and whether you're carrying any cargo.

Once you choose the cassette, then pick the derailleur to go with it. Or, select the long cage derailleur in case you change your mind with cassettes.

This guy already has an 11-32 with a long-cage derailleur. Why should he buy anything new? His bike works.

Likely if he got the SS he would need to fiddle with the B screw and Possibly have issues with too short a cage anyway. So ... possibly he would need to buy both a derailleur and an 11-28 cassette to get back to where he is now.

[MENTION=392454]CliffordK[/MENTION] raises some good points. If this person in primarily interested in keeping up on group rides ... either he already is or he already isn't. And, he is either using the whole cassette or he isn't.

If he is not using the top couple cogs, then he Might want to get a closer-spaced cassette. It Might make his group rides easier because he Might find it easier to find the perfect gear for his fitness level and the speed of the peloton.

Or he might end up buying a cassette and noticing no difference. I ride both 11-28 and 11-32, and there are plenty of close enough ratios in there, for my needs, Everyone's needs vary. These are things the OP needs to consider.

I do notice that at no time does the OP seem to want to replace his cassette, in which case the answer is simple: NO, do not replace the derailleur.

I do like to tinker with my effort a bit by popping up or down a single tooth.

Ok, so I'm not a fast rider, but at moderate effort at 15 to 20 MPH, I'll occasionally look down and realize that I'm cruising along in the small ring (front). I'll pop it up to the big ring. And, not gain that much speed.

I suppose I've realized that I am not nearly as tied to a single gearing as I had thought.

I do the same, sometimes ... there is nothing like finding a sweet spot ... and then finding a sweeter spot.

Other times it takes all my effort just to get back home in whatever gear.

Happens to me after short, sharp hills ... (well, what passes for "hills" out here ... ) I drop into the small ring, shift up near the crest, shift up again ... and keep going down the cassette while forgetting about the front. I bet if I did a lot of fast group rides though, I might forget less often.

The notion of me doing "fast group rides" is too funny .....

your setup works for you, why on earth would you change it just because others use something different?

if your setup doesnt work for you, due to you not needing such a wide range of gearing, then change it with a new cassette and chain. The derailleur wont affect anything and buying a short cage instead of your current GS will just mean less $ in your pocket.

if that's worth being like the others, then make the change.

Don't replace the derailleur without first replacing the cassette.

It would be easy enough to say lock your rear derailleur into the range 11/25 by adjusting the limit screws to exclude the 28/32T sprockets.

Ride it for a bit and see how you like it.

Then if you wish, source a 11/25 cassette and revisit the derailleur questions.

I appreciate the notes. This isn't a matter of trying to be like the others. It's not a matter of being a follower. It is a matter of wondering if my setup is correct as I see others are different.

There is more than one right answer, is the answer. Your bike likely has a bigger biggest cog than theirs so you need the longer cage.

The question you might want to ask, is "Do I use the top one or two cogs on my cassette?" But I wouldn't worry much. For about $100 you could get a 11-28 or 11-25 and a short cage derailleur and do actual scientific tests, riding the same route day after day, using the same rest, recovery, and nutrition and seeing if there was a difference. I would bet any variation would be completely within the realm of experimental error.

Your bike is different than theirs in that it has a wider-range cassette. That is the real difference. The long-cage derailleur is necessitated by the wider cassette. Next move is yours.

me, i'd just ride.

Sounds good. Thanks folks.