What is the point of a short cage Ultegra derailleur?

Father Faff

Why not just fit the slightly longer cage derailleur to new bikes which can handle a greater range size of casette such as 11-32T? Is it just that a short cage saves a few grams or is there more to it than that?

Bozman

I'd guess that the sc derailleur has always been the standard with a 12/25 or 11/23 cassette, but since the uptake of larger cassettes they've had to expand production to medium and large cage derailleurs?
Probably bull5hit but it sounds like a good reason.

g00se

Short cages will - supposedly - give you slicker changes compared to longer cages. That's the story but can't say it will or not.

racingcondor

The shorter cage should flex less and assuming they're supported by the same type of spring should keep your chain under tension better over poor surfaces (shorter lever).

No idea if there is any practical difference between short and medium though.

fast as fupp

some of us neither want nor need 'mtb' cassettes on our bikes.

Monty Dog

If you're racing, you don't want the weight of a dinner-plate cassette and the slightly slower shifting from a long-arm mech.

rafletcher

The as and gs rear mechs have exactly the same cassette capacity. The gs is for a triple chainset and the as for double (standard or compact). Check the tech docs.

Father Faff

Some good points there - it is so embarrasing having a "mtb" cassette because I'm not being a fit young racer who can sprint up 1:20 or even 1:25 hills here in the Dales!

Just to take up one point do you therefore think I'd be okay using an Ultegra 6800 11-32 cassette on a 50/34 with a short/standard derailleur?

Bozman

Father Faff wrote:

Some good points there - it is so embarrasing having a "mtb" cassette because I'm not being a fit young racer who can sprint up 1:20 or even 1:25 hills here in the Dales!

Just to take up one point do you therefore think I'd be okay using an Ultegra 6800 11-32 cassette on a 50/34 with a short/standard derailleur?

I've got a feeling that 30 is the max that you can use on an sc.

topdude

Anyone care to explain why "short cage mechs give crisper shifting" ?
Seems to me, regardless of the cage length, the top jockey wheel is in an identical position relative to the cassette whichever cage you have. A longer cage is just there to tension a longer chain. The geometry and pivots are the same. Or is this another cycling myth that keeps being handed down ?

me-109

Father Faff wrote:

1:20 or even 1:25 hills

1-in-25 is a hill? 1:25 is a ratio, i.e. 1 ft up for every 25 foot horizontal. Do you mean 25%? That's 1:4 (1-in-4). That's more like a hill!

ai_1

fast as fupp wrote:

some of us neither want nor need 'mtb' cassettes on our bikes.

That's it. Call larger range cassettes "mtb" cassettes and imply there's something wrong with them. :roll: Feel superior now?

The question wasn't whether you need a longer de-railleur, it was whether there's an advantage to the shorter one.

Moonbiker

Why don't beginners just stick to the flater roads were they belong then they won't need the ugly silly dinner plate mtb cogs

Or they can walk up hills

Essex Rouleur

Father Faff wrote:

Some good points there - it is so embarrasing having a "mtb" cassette because I'm not being a fit young racer who can sprint up 1:20 or even 1:25 hills here in the Dales!

Just to take up one point do you therefore think I'd be okay using an Ultegra 6800 11-32 cassette on a 50/34 with a short/standard derailleur?

In a word, no. You cant use a short/standard derailleur on a 11-32 cassette. The max a standard rear mech can handle is 11-28t.
If you want 11-32 then you need the long cage (or medium as they sometimes call it).

If you try and put a standard cage on a 11-30 or 11-32 cassette you will basically pull the pulley arm too far on the mech and put it under strain. Also the top jockey wheel wont clear the biggest cog with enough clearance.

Trust me, i tried it once and ripped the rear derailleur apart!

Father Faff

Thanks Essex Rouleur.

And yes I've been found out - I am one of those chunky mtbers who has gradually been pulled over to the darkside of road cycling in the hope that the crashes won't be so damaging only to find that the crashes tend to cause different types of injury such as removal of lots of skin and complete trashing of expensive Italian lycra....

freezing77

Essex Rouleur wrote:

Father Faff wrote:

Some good points there - it is so embarrasing having a "mtb" cassette because I'm not being a fit young racer who can sprint up 1:20 or even 1:25 hills here in the Dales!

Just to take up one point do you therefore think I'd be okay using an Ultegra 6800 11-32 cassette on a 50/34 with a short/standard derailleur?

In a word, no. You cant use a short/standard derailleur on a 11-32 cassette. The max a standard rear mech can handle is 11-28t.
If you want 11-32 then you need the long cage (or medium as they sometimes call it).

If you try and put a standard cage on a 11-30 or 11-32 cassette you will basically pull the pulley arm too far on the mech and put it under strain. Also the top jockey wheel wont clear the biggest cog with enough clearance.

Trust me, i tried it once and ripped the rear derailleur apart!

There are many threads and testimony that a shimano short cage derailleur will work with a 11-32 cassette. It very much depends on the geometry of the rear triangle, dropout and gear hanger.

Father Faff

Yes, there are indeed many stories of using a short cage with a largerer casette, but if I'm going to run a bigger cassette anyway I might as well match it to the correct (longer) cage. However my OP was just asking if there was really any particular disadvantage to a long-cage as opposed to a short cage derailleur. I think the general opinion is there is not a lot of difference unless perhaps you are racing where very gram saved and microsecond on change speed counts (but of course if you are racing you would never need a big cassette anyway - although having said that there were a number of pros dismounting on the steep little cobbled hills in Flanders last weekend!)

ai_1

Father Faff wrote:

........I think the general opinion is there is not a lot of difference unless perhaps you are racing where very gram saved and microsecond on change speed counts (but of course if you are racing you would never need a big cassette anyway - although having said that there were a number of pros dismounting on the steep little cobbled hills in Flanders last weekend!)

I'm not sure that's true. I think Contador has been known to use a SRAM WiFli with a 32t sprocket. I know he was reported to be using this in the 2012 Vuelta. Don't know if it's been a regular feature since when there's steep gradients.

rolf_f

Essex Rouleur wrote:

If you want 11-32 then you need the long cage (or medium as they sometimes call it).

Whoever 'they' are, they shouldn't be calling long cage mechs 'medium' as the two are different things!

racingcondor

topdude wrote:

Anyone care to explain why "short cage mechs give crisper shifting" ?
Seems to me, regardless of the cage length, the top jockey wheel is in an identical position relative to the cassette whichever cage you have. A longer cage is just there to tension a longer chain. The geometry and pivots are the same. Or is this another cycling myth that keeps being handed down ?

That's a good point too.

I guess continuing on from my original post there is a likelihood that the shorter cage maintains chain tension better so there might be some truth to it. That said my whole argument swings on all the derailleurs running with identical springs and I'm pretty sure that the likes of Shimano would put a stronger spring in (or more likely redesign the lot) if there was any noticable loss in shift quality.

I really doubt there is any real difference apart from the 10-15g in weight (extra chain link and a bit more cage) which these days means a lot to the marketing guys...

fast as fupp

Ai_1 wrote:

fast as fupp wrote:

some of us neither want nor need 'mtb' cassettes on our bikes.

That's it. Call larger range cassettes "mtb" cassettes and imply there's something wrong with them. :roll: Feel superior now?

The question wasn't whether you need a longer de-railleur, it was whether there's an advantage to the shorter one.

now?

i already did. :shock:

markhewitt1978

Ai_1 wrote:

I'm not sure that's true. I think Contador has been known to use a SRAM WiFli with a 32t sprocket. I know he was reported to be using this in the 2012 Vuelta. Don't know if it's been a regular feature since when there's steep gradients.

The Vuelta is renowned for ridiculous gradients, and of course the pros will think nothing of running a different cassette every day depending on the terrain of the stage. He was probably running it with a standard, mind.

Father Faff

Rolf F wrote:

Essex Rouleur wrote:

If you want 11-32 then you need the long cage (or medium as they sometimes call it).

Whoever 'they' are, they shouldn't be calling long cage mechs 'medium' as the two are different things!

Errr....Shimano.

rolf_f

Father Faff wrote:

Rolf F wrote:

Essex Rouleur wrote:

If you want 11-32 then you need the long cage (or medium as they sometimes call it).

Whoever 'they' are, they shouldn't be calling long cage mechs 'medium' as the two are different things!

Errr....Shimano.

Well someone needs to explain the difference to them then so they don't get it wrong in future!

They definitely aren't the same thing.......

gloomyandy

I'm pretty sure they are Sram X7 mtb rear mechs, not Shimano ones. No idea if Shimano make three different length road mechs or not.

rolf_f

gloomyandy wrote:

I'm pretty sure they are Sram X7 mtb rear mechs, not Shimano ones. No idea if Shimano make three different length road mechs or not.

They are - it was the first pic I could find with a matching set. I was mildly surprised to find all three available in one model.

(Simplistically) Long cage are MTB or touring mechs for use with triple chainsets. Medium cage is the halfway house for road bikes that need a wider range and short cage is the standard road bike size. You'd hope that Shimano would understand that and not confuse people but you never know......

mitchgixer6

Ai_1 wrote:

Father Faff wrote:

........I think the general opinion is there is not a lot of difference unless perhaps you are racing where very gram saved and microsecond on change speed counts (but of course if you are racing you would never need a big cassette anyway - although having said that there were a number of pros dismounting on the steep little cobbled hills in Flanders last weekend!)

I'm not sure that's true. I think Contador has been known to use a SRAM WiFli with a 32t sprocket. I know he was reported to be using this in the 2012 Vuelta. Don't know if it's been a regular feature since when there's steep gradients.

The Wi Fli isn't a standard short cage derailiuer though. It's got a much longer cage than standard.

ai_1

mitchgixer6 wrote:

Ai_1 wrote:

Father Faff wrote:

........I think the general opinion is there is not a lot of difference unless perhaps you are racing where very gram saved and microsecond on change speed counts (but of course if you are racing you would never need a big cassette anyway - although having said that there were a number of pros dismounting on the steep little cobbled hills in Flanders last weekend!)

I'm not sure that's true. I think Contador has been known to use a SRAM WiFli with a 32t sprocket. I know he was reported to be using this in the 2012 Vuelta. Don't know if it's been a regular feature since when there's steep gradients.

The Wi Fli isn't a standard short cage derailiuer though. It's got a much longer cage than standard.

Eh... That was my point! I think you may have gotten something a little confused.
The previous post I quoted said "of course if you are racing you would never need a big cassette anyway". I was pointing out that to the best of my knowledge even some of the best cyclists have been known to use big cassettes.

mitchgixer6

Aye awright! Keep yer hair on!