Shimano Road Rear Derailleur Capacity: The untold truth and full analysis

Shimano SS and GS rear derailleur cage length and different cassette sizes.
explaining the limitations of a rear derailleur regarding cassette sizes. explaining rear derailleur capacity and shifting range. showing shimano recommended values for SS (short) and GS (medium) rear derailleur cassette comparability.

[@francislai5270]

Excellent research and video

[@maxgrass8134]

Thanks!

[@nelsonsilva6842]

Great video that addresses all points. Rarely seen on youtube!

[@mikebarone2]

Great job! Thank you for your attention to detail and the slow and articulate explanations.

[@ROGERSNIGEL]

Excellent research and clearly explained without the usual nonsense gimmicks and chat.Thanks

[@rudgemckenney5178]

Thank you Max. I have been searching for this exact information for awhile and this video is perfect. I have the Ultegra R8000 system and the data you have provided will be important in my decision to switch the chainrings.

[@havefunandbikestuff]

Very good information. I currently need the extra gear of 34t on rear as I am climbing steeper grade mountains. I'm however using a R8000 ultegra front derailleur and rear derailleur in mechanical setup. My front is a compact chain ring set. It's been since 2018 since I used the 34t rear cassette, so I needed a refresher of what is allowed so I came here to this video. Thank you for this.

[@barryrainey143]

Thanks for this video. It answered a number of questions. I am doing the exact same set up.

[@iannawaz]

This video is amazing! Excellent explanation and practical demo.

[@maxrevell3830]

The 14 tooth minimum (or maximum depending on how you look at it) is stipulated in some of the junior categories of racing, so it is a relevant figure for some. Also had Sora 3000 (9speed) running the 12-36 (recommended max. 34) cassette and it was a tight fit but worked great

[@CyclicCollective]

Nicely explained. I am running a capacity of 46 being 48-31 front and 11-40 rear on the new Shimano GRX810 gravel group set. This combination work perfectly, even big-big and small-small. Note that the GRX810 rear has a longer cage than the GRX812 which is intended for a 1x system. There are a number of people using the 2x Di2 version with the same success. I regularly do long climbs climbs 15-25% gradient and want to keep up a reasonable cadence and the GX810 rear mech will do it. I suspect the GRX600 an GRX400 would do likewise. The standard Shimano 2x GRX400 runs a capacity of 41 being 46-30 front and 11-36 rear (10 speed) so I suspect the cage will be equally long. The GRX810 runs much larger gears in the cage also which increases the cage capacity without increasing the length.

[@user-ek9zp2sv2n]

Inspired by this and similar vids, I changed the 11-28 for a 11-34 on my Felt CX bike. Kept the short/med cage 105 but used the Road Link and also subbed a 34 tooth chainwheel for the 36. Didn't even need to adjust the chain length. Now I have the 1:1 lowest ratio. The rest is up to me.

[@michaelb1716]

Great video! Very informative and well explained 👍

[@jerryavalos9610]

I just caught your video while getting ready for work, I am going to watch it thoroughly. I am in the process of re-gearing all my bicycles. One bicycle that I am doing is a 7 speed 1992 Schwinn Paramount with a standard 53/39 crank, I have a vintage RD-1056GS that I plan to put on because where I live is very hilly. The max sprocket is 12-28T, I don't plan on exceeding the max sprocket, but will have to go to a GS and not a SS because the SS total capacity is 28, I would feel comfortable with a GS.

[@imaginehydreigons5377]

always go with ss if you can as it allows for snappy shifting and is less prone to hitting objects.

[@r.williams8349]

Very helpful video- thank you!

[@davidparker8475]

Thanks for your work. good stuff! I run a mid cage Ultegra set up with 11-34 rear and 52/36 front. If I didn't ride mostly in the hilly Hocking Hills of Ohio, I'd go with 11-30 and a short cage. I've used an 11-28 with a 53-39 in the front with a Dura Ace short cage. It worked well. It just didn't have a tall enough gear for my area.

[@egasamaral]

Great explanation. Thank you.

[@user-zt2ob3dn3h]

Thx for this fine video!

[@tomwarrick4945]

Hey I never thought to put screw in from other side Thanks that’s cheaper than buying a extender I’ll give it a try on next project

[@jorgeinacio7461]

Perfect explanation

[@markbulmer1840]

Hi ive just purchased a 11-32 cassette but not fitted it yet. Ive got the 105 short cage that was running 11-30 cassette. Watching your video i only go as far as the 3rd ring down on the biggest chainring. And on the small chainring I don't go as far as 3rd off bottom cassette ring so it should be ok to run looking at this. Cheers for your vlog.

[@AreaCode865]

Really helpful, thanks very much indeed ❤

[@ronb9901]

I have those same rims! 👍👍. Excellent video.

[@petesharp3640]

Outstanding. Thank you.

[@CarsandBikes]

Should I use a short or long cage rear der. for a 12-30 10-speed with a standard Dura Ace 7800 crank?

[@zephyr789]

Great video. Question about optimum chain length please. How many links are you using in your setup please? 108? 110?

[@marianneoelund2940]

There isn't a single optimum value, because it also depends on chain stay length.

[@ariehandoko6806]

Is it possible to install 11-36 cassete with chainring 52-36 with RD ultegra?

[@brianbell1057]

Question: I ride a 1x11 setup so total capacity is not a concern, but "Low sprocket_Max" is what I care about. When I look at the pictures of the SS and GS rear derailleurs (i.e. Ultegra), they look identical except for the length the of the jockey pully cage (which is more applicable to total capacity). Therefore, why is there a difference in "Low sprocket_Max" between SS and GS? Maybe I'm missing something but the pictures look identical to me from the frame mounting point to the upper jockey pully. Any insight would be appreciated.

[@marianneoelund2940]

The GS model may have a different balance between the cage spring and B spring stiffness or pre-load. Also, the derailleur parallelogram on the GS may operate at a steeper angle, so the jockey wheel moves downward more when shifting to the lowest gear. Differences will be subtle and may only be detectable by careful measurement.

[@mojovelo8484]

@@marianneoelund2940 Thank you for your response!

[@imaginehydreigons5377]

is 11-34t 8speed cassette and 52tsingle in the front ok with ss rd with a max low cog of 32t?

[@red92diaz]

What if you’re using a 1x10 set up. I have a 53t chainring with 10 sp cassette 12-25t. Based on your video it gave me 66 total range

[@derdualeraum356]

Is there any major disadvantage of the GS? I think for most people GS is better suited than SS and it should be standard for road bikes in hilly regions.

[@blizzbee]

GS is a bit not as smooth if you change gears quite often, and ofcourse the GS has more weight than the short cage SS one. So the best pick is... to follow the cog set you choose, if the cog set is 11-28, go for the SS. Other than that (11-30 / 11-32), go for GS.

[@paulb9769]

My capacity is 37. I want to use a Shimano GS Medium but the spec says my 16t front difference is to much? "Maximum Chainring Size Difference: 10T (medium GS version), 22T (long SGS version)"

[@innerlocus]

@ 13:35 I think I may have ripped off my ultra derailleur not expecting the downshifting while on the large front chainring. FMI

[@kimtruong4676]

Hi, do you know...Rather than going to a Medium cage derailleur, can you increase your lowest cog range (from 28t to 32t) by replacing the lower cage pulley on the short cage deurailleur from 10t to a 14t?

[@marianneoelund2940]

Changing the pulley to 14T will increase the derailleur total capacity by 2 teeth. It should work slightly better than the setup shown in the video, if you set the chain length optimally.

[@mashkal2006]

Hi Max Thank you for a thorough and informative video. Do you think you would have been able to go to 34, if you had a 1X setup?

[@maxrevell3830]

it might depend on the size of your chainring but I would think a GS (medum cage) would be better, you could probably fit a 36 too. You could also use a derailleur hanger extender such as a roadlink to move the rear mech away from the cassette and thus give you more clearance for bigger cogs

[@mashkal2006]

@@maxrevell3830 I tired and it worked flawlessly. It's an old road bike (7speed). I tried it both 1x: 13-34 freewheel and 52t chainring, and 2x with a 44/52 crankset. No issues whatsoever. Thank you again for you video that inspired me to experiment

[@maxrevell3830]

@@mashkal2006 great stuff, I'm actually a different Max to the guy that made the video but always good to share tips and ideas!

[@gpulgar]

@@mashkal2006 hey, Joakim! for the 1x setup (52T), did you use a hanger extender, or just installed the derailleur right ahead?

[@mashkal2006]

@@gpulgar installed it straight on. It's an old 10s 105 SC deraileur i think. photos.app.goo.gl/hkucbWBv1GCsoFuN8 (hope it works - picture of 1x with large chainring) and photos.app.goo.gl/gmKBQqPdEqtjhceLA (13-34 casstte and 53/44 chainset) both setups worked great. The 1x is a dream now since I've changed the chainring to a narrow-wide and the the chain to a 11s chain I had laying around. its quite and it changes gears with no isues what so ever.

[@michaelvandinther]

Hi Max - could you please post the approx length (cm/mm) from centre to centre of both pulley cogs? Im trying to figure out if I have SS or GS. Mine measures 6cm/60mm

[@black7987echo]

SS

[@TheWoogeroo]

So, is there any reason for the SS derailleurs to exist in the first place? Why don't they just sell the gs (medium) ones and simplify their lineup?

[@giovannispinotti]

SS derailers are lighter and can get the pulley closer to the cassette. That's minimal for normal users, but pros who need very precise and fast shifting and will never mount lower gears, they might notice the difference.

[@giovannispinotti]

Actually no need to get the full derailer, just buy the two GS plates and swap them in the SS derailer.

[@mountainrun]

Shimano apparently only sells the inner so people can't do that.

[@giovannispinotti]

@@mountainrun I replaced a shimano ultegra short cage with a medium cage myself following this tutorial: kzbin.info/www/bejne/eH-np4WoiJVlhZI. Look for the manual of your derailer and search for the parts numbers, you should find both parts of the cage.

[@VicCampbell1]

Hi. Thanks for your video. Is it possible just to replace the 2 cage plates (inner and outer) from SS plates to GS plates? About €30. Instead of having to replace the whole derailleur?! Which would be much more expensive! Thanks!! P.s. I have 52/36 front; 11-32 cassette. Shimano Ulegra Di2 rear derailleur 6870.

[@giovannispinotti]

Sure possible, I followed this tutorial: kzbin.info/www/bejne/eH-np4WoiJVlhZI

[@shinrips]

Why large cog to large sprocket?

[@mountainrun]

Just for determining correct chain length.

[@ozgurinsan]

i can confirm that 8050 di2 ss derailleur with 11-32 cassette and 50/34 chainrings does not work.

[@timtaylor9590]

chain tension

[@bisiklettin]

Range ≠ Capacity, at least logically, unless capacity is a reference to range - and not actual number of teeth. As, only roughly HALF of the chain is wrapped on cog and sprocket!

[@DiLari1960]

Too long chain. Take a link or two off.

[@ariehandoko6806]

Is it possible to install 11-36 cassete with chainring 52-36 with RD ultegra?

[@extravaganza69]

Yes it is

[@ariehandoko6806]

@@extravaganza69 thanks