# Rear Derailleur: Short cage or medium cage?



## Wood Devil (Apr 30, 2011)

I'm upgrading the components on my indoor trainer bike, from 10-speed 105 to 11-speed Ultegra.

I've got a 52/34 up front, and my cassette preference is usually 11-28T. Would I be needing a medium cage rear Ultegra 6800 or would a short cage work better?


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## Jay Strongbow (May 8, 2010)

Wood Devil said:


> I'm upgrading the components on my indoor trainer bike, from 10-speed 105 to 11-speed Ultegra.


oh my.


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## cxwrench (Nov 9, 2004)

You need the medium if you're ever going to go big/big. If you never ever never go big/big the short should work. I'd recommend medium. Size your chain w/ the small/small method.


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## MMsRepBike (Apr 1, 2014)

SS version is fine.


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## cxwrench (Nov 9, 2004)

Capacity for the SS is 33 teeth. The OP needs to wrap 35. Capacity for GS is 37. Do the math.


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## Wood Devil (Apr 30, 2011)

Thanks, guys. I don't do much cross-chaining, and very seldom do the 52/28, especially indoors. I guess the SS short cage should suffice.


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## MMsRepBike (Apr 1, 2014)

cxwrench said:


> Capacity for the SS is 33 teeth. The OP needs to wrap 35. Capacity for GS is 37. Do the math.


An SS will do a 53/39 and an 11-28 all day. It's within spec.

The issue being the OP using a small chainring out of spec creating a huge jump in the front.

Wrapping the extra slack from the 34 front ring shouldn't be a big issue with the SS. 

Preaching Shimano's wrap capacity is fine and all but it's not real life. The SS will work fine, even with the OP's out of spec front setup. 

Just use the small/small chain length method and make it as long as you can. Big/big should still work fine, albeit a stretch.


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## QuiQuaeQuod (Jan 24, 2003)

Wood Devil said:


> Thanks, guys. I don't do much cross-chaining, and very seldom do the 52/28, especially indoors. I guess the SS short cage should suffice.


Do you ever lose track of your gearing when doing hard trainer rides? 

Do you ever plan on riding this bike outside with that same cassette?

If yes, you might consider the medium cage as the better choice to avoid potential problems. If no, not really going to be an issue going with the short cage for you.


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## Jay Strongbow (May 8, 2010)

Kind of surprised I'm the only one seeing it fit to be a jerk here.

Seriously though OP, it's pretty stupid to upgrade components on a bike you use inside on the trainer. I honestly don't about strangers on the internet blowing money but certainly you can find something better to do with it. Didn't you post not to long ago about getting a cheap power meter because good ones were to expensive or something like that? And this makes sense though?


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## QuiQuaeQuod (Jan 24, 2003)

Jay Strongbow said:


> Seriously though OP, it's pretty stupid to upgrade components on a bike you use inside on the trainer.


Depends on what a person values.

For what I value, I agree totally it makes no sense to do anything to a trainer bike other than keep in functional at the lowest cost possible. Trainers are where bikes go to die a slow death.


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## ExChefinMA (May 9, 2012)

Jay Strongbow said:


> Kind of surprised I'm the only one seeing it fit to be a jerk here.
> 
> Seriously though OP, it's pretty stupid to upgrade components on a bike you use inside on the trainer. I honestly don't about strangers on the internet blowing money but certainly you can find something better to do with it. Didn't you post not to long ago about getting a cheap power meter because good ones were to expensive or something like that? And this makes sense though?


What if he's matching the components to what he has on this outdoor bike?

My CAAD 10 lives on my trainer during the spring/summer but has the exact same drivetrain as my SuperSix because I wanted the same gearing.

Just sayin'

EEC


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## Jay Strongbow (May 8, 2010)

ExChefinMA said:


> What if he's matching the components to what he has on this outdoor bike?
> 
> My CAAD 10 lives on my trainer during the spring/summer but has the exact same drivetrain as my SuperSix because I wanted the same gearing.
> 
> ...


-Gearing and an entire groupset are not the same thing. 
-Cassette and possible crank take care of that. 
-Gearing needs on the road are nothing like the trainer.
-That is a separate topic from 'upgrading" to Ultegra.


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## ExChefinMA (May 9, 2012)

Jay Strongbow said:


> -Gearing and an entire groupset are not the same thing.
> -Cassette and possible crank take care of that.
> -Gearing needs on the road are nothing like the trainer.
> -That is a separate topic from 'upgrading" to Ultegra.


I was taught many years ago by a very wise man, train the way you intend to do an action. Does not matter if it shooting, cycling, insert repetitive action here. It builds muscle memory, regardless if you “need” specific gearing on the trainer vs the road is it not better to train with what you will be using on the road? 

But of course, this is just my opinion that and at least $5 will get you your favorite cup of coffee. 



EEC


Sent from my iPhone using Tapatalk


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## Kontact (Apr 1, 2011)

ExChefinMA said:


> I was taught many years ago by a very wise man, train the way you intend to do an action. Does not matter if it shooting, cycling, insert repetitive action here. It builds muscle memory, regardless if you “need” specific gearing on the trainer vs the road is it not better to train with what you will be using on the road?
> 
> But of course, this is just my opinion that and at least $5 will get you your favorite cup of coffee.
> 
> ...


Hopefully the geometry of his indoor training bike matches his outdoor bike.


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## Jay Strongbow (May 8, 2010)

ExChefinMA said:


> I was taught many years ago by a very wise man, train the way you intend to do an action. Does not matter if it shooting, cycling, insert repetitive action here. It builds muscle memory, regardless if you “need” specific gearing on the trainer vs the road is it not better to train with what you will be using on the road?
> 
> But of course, this is just my opinion that and at least $5 will get you your favorite cup of coffee.
> 
> ...



You missed my point. A trainer is not the road, you can ride as hard or easy as you want to simulate the best you can what you would do on the road, but on the trainer you won't be using the same gears to do it. For example I use 50x11 on the road quite a bit at a high cadence thanks to gravity.....but I've never have and never will come close to using 50x11 on the trainer. 
Granted I'm not factoring in those new smart trainer things and whatever then might do.

And by the way your wise man isn't very wise. There's a reason participants of every sport at every level who are any good do specific drills or workouts to isolate and develop specific skills or muscles rather than doing what the do when it matters every practice. 
Do you think, for example, Bolt just sprints for training?


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## Kontact (Apr 1, 2011)

Generally speaking, there is no great reason for a trainer with variable resistance to require more than a single gear on the bike.


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## rcb78 (Jun 15, 2008)

Have you guys ever used a smart trainer? Mine feels pretty damn similar to my road rides, enough so that I use the full range of gears just like I would outside. Not arguing for or against the OPs setup, but the new gen of trainers have really changed indoor riding.


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## Jay Strongbow (May 8, 2010)

rcb78 said:


> Have you guys ever used a smart trainer? Mine feels pretty damn similar to my road rides, enough so that I use the full range of gears just like I would outside. Not arguing for or against the OPs setup, but the new gen of trainers have really changed indoor riding.


Nope, I've already acknowledged that my comments don't factor those things in though.


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## scottma (May 18, 2012)

Smart trainer in erg mode will hold you to a power level, typically a % of FTP no matter what the wheel speed is or what gear you are in. In that case gears dont do anything. If the smart trainer is used in course, or slope mode, the resistance is increased with gradient and just like on outdoor riding, you control your power effort and gearing has same effect as outdoor riding.


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## cxwrench (Nov 9, 2004)

Funny how these threads wander so far away from the point of the OP.


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## Kontact (Apr 1, 2011)

scottma said:


> Smart trainer in erg mode will hold you to a power level, typically a % of FTP no matter what the wheel speed is or what gear you are in. In that case gears dont do anything. If the smart trainer is used in course, or slope mode, the resistance is increased with gradient and just like on outdoor riding, you control your power effort and gearing has same effect as outdoor riding.


If the smart trainer varies resistance without regard to wheel speed, there would be on reason to have more than one gear. Unless shifting is just fun.


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## ogre (Dec 16, 2005)

Kontact said:


> Hopefully the geometry of his indoor training bike matches his outdoor bike.


And if normally rides with disc brakes, that’s a whole new discussion. We could start a thread to end it all.


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## scottma (May 18, 2012)

Kontact said:


> If the smart trainer varies resistance without regard to wheel speed, there would be on reason to have more than one gear. Unless shifting is just fun.


Exactly. If you have a smart trainer with actual erg mode (not all do) and only used erg based workouts, a SS would be a nice setup. 250W @ 53 x 11 or 34 x 28 is 250W. I just use a gear to run around 16-22 MPH with low/high cadence. It is good to mix in some slope based workouts sometimes just to change it up so then you need the gears.


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## sasquatch16 (Feb 7, 2013)

Getting back to original question the SS probably will work but if your buying a new derailleur why not buy the right one. Cost difference is minimal


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## crankout (Mar 3, 2015)

MMsRepBike said:


> SS version is fine.


The OP needs a medium cage.


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## Lombard (May 8, 2014)

cxwrench said:


> Funny how these threads *wander* so far away from the point of the OP.


As long as they don't stretch, they're OK.


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## Lombard (May 8, 2014)

Wood Devil said:


> I'm upgrading the components on my indoor trainer bike, from 10-speed 105 to 11-speed Ultegra.
> 
> I've got a* 52/34 *up front, and my cassette preference is usually 11-28T. Would I be needing a medium cage rear Ultegra 6800 or would a short cage work better?


You have a 52/34 up front, really? That's an 18 tooth drop. Does it shift OK? A 52/36 or 50/34 is a big enough drop as it is.


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