Long Cage Ultegra Mech with 28t Cassette?

[Siclo]

Er...doesn't the front end make a difference?

Ultegra 11 speed long cage capacity = 37 teeth

So running 50/34 with 11-34, capacity required = 39 teeth ((50-34)+(34-11)), that's beyond the limits but not impossible depending on frame geometry, shimano are known for conservative specs, or use a road link

Running 52/39 with 11-34, capacity required = 36 teeth, job's a good 'un.

EDIT: fwiw I've got a long cage mech on 50/34 and 11/32 and there's no way the mech will wrap any more chain in my case

 

[Joffey]

If he is running 11-34 and all is fine in small - small, then all will be fine in small - small with an 11- 28 the derailleur will not be under as much tension in 28 as 34, the chain can be shortened if you want to, but if it isn't causing a problem in small - small with a 11 - 34 it won't cause a problem with 11 - 28.

Exactly what I thought, I'm not sure what world ending problems Alex is predicting after all both cassettes have an 11t and a 28t on no matter which one you are using. As long as you are set up for the 11-32 swapping it to an 11-28 will work. You could reduce the chain length if you wanted but if it is running fine on 11-32 there is no need.

Thank you for talking sense and stopping me thinking I was going out of my mind!

 

[Venod]

Thank you for talking sense and stopping me thinking I was going out of my mind!

Yorkshire common sense.

 

[Joffey]

Er...doesn't the front end make a difference?

Ultegra 11 speed long cage capacity = 37 teeth

So running 50/34 with 11-34, capacity required = 39 teeth ((50-34)+(34-11)), that's beyond the limits but not impossible depending on frame geometry, shimano are known for conservative specs, or use a road link

Running 52/39 with 11-34, capacity required = 36 teeth, job's a good 'un.

EDIT: fwiw I've got a long cage mech on 50/34 and 11/32 and there's no way the mech will wrap any more chain in my case

I'm running a 52/36 at the front and a 11-34 at the back on a med cage R8000 rear mech. It does look a little funny but it was the only way to get the same low gear as my other bike which is 50/34 and 11-32. My 52/36 chainset is carbon so a new cassette was cheaper!

Either way it all runs fine.

 

[Siclo]

Ah, the R8000 has a higher capacity than 6800. In the OP's case 11-32 changing to 11-28 will be fine.

 

[cosmicbike]

Thanks for all the responses, it's all nice and clear now (like mud) I'll stick the 11-32 on with the current chain and see how it runs on the stand, I can add/remove links as needed on the new chain.

 

[Siclo]

Don't do that, chances are you'll knacker the mech because the chain will be too short for big-big.

Change the mech, change the cassette to 32, change the chain, then you can go back to 28 without changing the chain.

As an aside, if it was me, I'd have a chain for the 32 and a chain for the 28. Cassettes and chains wear together and you can get slipping if you have a worn chain with a newer cassette. This does depend on your attitude to chain wear, personally I just ride it until the whole lot is destroyed. If you are the sort of rider that changes the chain at 0.5% wear, you can swap cassettes to your hearts content and keep the same chain without slippage.

 

[Siclo]

Alternatively have near identical bikes, one runs 11-32 and one runs 12-25, which was my solution, of course I did have to find other reasons to convince the treasurer.

 

[pawl]

I’m doing exactly the same thing.I am using a KMC chain with master link .I will keep the current Shimano chain which is barely worn and use if I want to change back to a28 ,with a Shimano master link,

Since the above reply,I have changed from Ultegra short cage max cassette 28 to 105 max cassette 32.

Before fitting the 105 mech tried the new cassette with the Ultegra short cage .Its possible I could have used the original mech Any one considering a similar change it might be worth trying the short cage first.

 

[cosmicbike]

Well that was a game My second hand and somewhat scratched Ultegra 6800 long cage mech had been somewhat fudged by previous owner, and the cable entry/adjustment was cross threaded. Suitably re-tapped, I wondered why no spring tension in the cage either. More fettling. After an hour I had a derailleur that was serviceable. New 11-32 cassette fitted, and a new chain. It has 118 links and I removed 3, the results look ok??
Big to big

And small to small

Not ridden yet, but goes through all the gears nicely on the stand.

 

[Ajax Bay]

IF in that top image the chain's on the large chain ring, fine. The small/small set-up (second image) looks good.
113 plus the quick link, then.

 

[cosmicbike]

IF in that top image the chain's on the large chain ring, fine. The small/small set-up (second image) looks good.
113 plus the quick link, then.

Yep, large chainring to 32t in the top pic, not a position it will get ridden in mind..

 

[youngoldbloke]

50/34 with 11-32 Ultegra 6800 GS is as was supplied on my Rose Xeon CRS, and standard spec on many bikes. No problems.