Do I Need A Short, Medium Or Long Cage Rear Derailleur? | Maintenance Tips

Bigger gear ratios need to have a compatible rear mech. Here's our guide to choosing the right one.
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If you decide you want a bigger sprocket on the back for climbing, chances are that you'll need a longer rear derailleur that will keep the right amount of tension on the chain and clear that big sprocket. With a fairly simple bit of maths, you can determine the right size you need. We also go into the other considerations you need when switching gear ratios - chain length for example.
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Leave us a comment below!

[@ygtcbee23]

I miss when GCN made simple to understand & helpful videos like this

[@johnjerizlopezignacio3891]

Zion Hezekiah cool! It worked! Stuck my chain between chainring.

[@vikram360]

This is by far one of my favorite GCN Maintenance videos - it's nice to hear why something works or why something doesn't work, as opposed to hearing that it 'just works'.

[@angelomedi]

why would the statement "just works" could be used to state something that does not work?

[@philadams9254]

3:16 - Sorry to hear about that Dan.

[@kryghyzho7868]

Note that for a large ratio cassette + short cage derailleur you can also just install something like a wolftooth roadlink. Its around 20 USD and works fine with a short cage DI2 rear mech combined with a 36 sprocket.

[@PHNX0]

Love your videos. This guy is the best at clearly explaining things. Thanks again

[@Jinxteru]

Exactly what I needed. Crisp and simple! Hats off!

[@HMPirates]

I bunged up my shimano tourney 7 speed the other day. Upgrading to alivio. Thank you so much for the timely video! 😃

[@backdoorslam]

wonderful video. Just tried to understand these two terms (total capacity and max. sprocket)! thanks GCN, you are the best!

[@xtremelangy]

Great timing for this video. Just about to replace my 11-28 rear cassette with an 11-32 ready for this years E'tape. I've already got a longer rear mech & new chain, so a bit of work to do.

[@karlInSanDiego]

Thanks Dan! Old video still helping to clarify the need for Short, Med, Long cages, years after you made it!😁

[@SloppySalad]

Yaaaaay! My question from however many years ago was relevant! :P Great video as always GCN ;)

[@belverticale]

Increasingly, Shimano are making medium-length road rear derailleurs as well as the short ones. I have the new Tiagra with a medium-cage and it's very smooth. The cassette is 11-34 which means a lovely low gear for steep hills when combined with the classic 34-50 compact crank up front. The big jumps in the cassette are all at the top end though if you're worried about the jumps between gears being too large when you're steaming along on the flat (my ten speed cassette is 34-30-26-23-21-19-17-15-13-11). I'd highly recommend the medium-cage option..

[@craigs1437]

Great video on this subject, well explained, and to the point.

[@samiautio9943]

Just changed my med cage der to short cage along with my cassette (11-32 to 11-28) and gear changes are just as Dan said, much crisper.

[@lucianonarno1408]

This video came out just in time! I'm in the process of upgrading my whole drive train, those complicated math equations will help out when choosing. I'm trying to get rid of my triple up front, it's not very fashionable as Si said. Lol.

[@PedalForward]

Helpful video, thanks!

[@kentlewan]

Great explanation. Thank you Sir!

[@bosanderspublictheology]

Very helpful and clear. Thank you.

[@galaxyjumper32084]

Thanks for the vid.... Very helpful

[@ilikelampshades6]

I'm running 52-36 chainrings and 11-40 cassette. It works even with a short cage di2 mech. you just need a road link and more links in chain

[@Ronin_Texas]

Thanks Dan & GCN 👍👍

[@tedgodfrey2708]

Brilliant!! Well Done DAN..

[@genlub60]

nice topic, exactly what I am looking for 😊🤔

[@tomharmon3193]

Great information 👍

[@VE7QRZ]

Thank you for the summery

[@Gerald-iz7mv]

great video. I have a Shimano MT210, 46/30, chainguard. and a Shimano XT 11/34 cassette. thats is a total differential of 39 The Shimano XT RD-M772 has SGS and GS: SGS: 9 gears, total capacity: 45T, smallest sproket: 11, front chainweel tooth difference: 22T GS: 9 gears, total capacity: 33T, smallest sproket: 11, front chainweel tooth difference: 22T That means only SGS would work right?

[@tonywest550]

Ive got Red Etap and just by adjusting B screw, can get it up onto 34, not ideal, so got red long cage to swop, BUT noticed the top jocky on both were in the same place, OK the long cage will take up chain slap, but the top jock will still be close to top sprocket, mech dropper does the trick China £ 2.00

[@rustygramm7104]

sometimes you can use a short cage with a wider cassette by adding some chain links and turning in the B-tension screw to get the jockey wheel spacing correct. Shimano 105 short cage rear mech can work with up to a 32t cassette on most frames, just be careful and know what your getting into and don't blame me if it goes wrong

[@Hardi26]

I have once cursed the long derailleur, because it was reaching to wet snow when riding along a bit too narrow to my skill car tracks on uncleaned road at winter, and it froze on derailleur and cassette. Maybe I was barking the wrong tree, and it actually was spraying from the wheels to there. But it was really frustrating I had to clean the cassette from ice after every 50 meters.. So maybe that's one disadvantage for long derailleur. Also longer one maybe bend easier since there's more leverage.

[@osmankhalid2005]

As per the formula given, here is the scenario in my case: Front chain ring: 42T - 24T = 18T Rear chain ring: 46T - 11T = 35T Total required capacity: 53T. However, I using a derailleur of capacity 43T (SHIMANO ALTUS Rear Derailleur RD-M310-Smart 8/7-speed). Is the rest of the capacity is covered by the 45 mm hanger, and fully tightening the adjuster screw?

[@liammcgough9969]

Thanks Dan! That was very helpful. Is it a better to change your derailleur for bigger gears or can you get away with an extender?

[@leedorney]

Ive always wondered why Shimano et al started fixing their blocks so that the specific sprocket sizes cannot be custom changed...ie the spacers are easily seperable and thus you can put together a block or sprocket set that you desire, ie not many sprocket sets come with an 18t sprocket which is a nice size rear gear to ride...they're also easier to clean as well!

[@grainfrizz]

Thank you, GCN!

[@farrelchinnappa9484]

Rear derailer extension hangers also work for bigger cogs with Short cage derailers

[@koDiacc]

hey GCN. gotta question: in recent stage races (tour du sud, tour de suisse) we had some crazy weather changes and so the strava profile recordings (elevation) were quite messed up. My father now says he never had this issue with his older ciclomaster bike-computer. do older devices use some better quality barometers or is it just that pros ride way faster and so the head-unit can keep up with adjusting air pressure = height #torqueback

[@metrocyc2774]

I have a medium cage when I should really have a short. Everything is fine except for cable rub at the derailleur because of the cable angle . This causes the cable to fray and eventually snap. Not too much of a problem if you can change cables and have spares.

[@Colwray1]

I'm running a giant TCR on an 11-28... Swopped it over to an 11-32 and swops over without any issues and still using the short cage derallier ...

[@thatwolffe3802]

When you pull it too much you cant get it up ): I think Dan is hinting at something. 3:13

[@spinpedal1327]

What if it's a single chainring

[@spyderspic666]

EXCELLENT VIDEO!!!

[@TurkiyeCumhurbaskani]

I got Di2 Ultegra 50/34 crank with 11-32 (11 speed) mid-cage , I have this set up because my area has lots of 10+% hills up to 22% grades

[@mynameisHOPKIRK]

Sounds like a good set up for a double.

[@criteriumgoat6525]

What a sexy spinning ratio!

[@Tonytruand09]

Hello! Nice video but what about, going up to 40 Tooth at the back (50-34 at the front) with a longer chain, keeping the same derailleur AND a roadlink? This set works perfectly fine and a lot of people are climbing Doi Inthanon at the modem with it. This is a cheaper solution and requires very little change.

[@Orgakoyd]

Hello Harley clone!

[@Tonytruand09]

+lite Roadie it doesn't really matter...... The guy is right. And people are doing it now as we speak. It works perfectly and it is cheaper. Now people believe and do whatever 😉

[@Orgakoyd]

Tonytruand09 I'm sure it works, I wasn't makign fun of him, just a friendly joke! But I'd personally rather a triple 30-39-50 with a 28 cassette which gives a low gear as low as 34-32, but works WAY better since you are never cross chained, you can also put a larger cassette than 28 like a 30 and it would still work and give you a super low gear. Any lower than that and you're better off walking.

[@zeromars9361]

can you please do a video explaining the several different types of handlebars for road bikes? #Torqueback

[@blackbeardbastard]

I run on 52/39 and 14/34, so that would make my differential 33, the same as yours. Yet, I'm using long cage derailleur because of the 34 cog in the back, and you run short cage, so the differential itself isn't enough to decide which one derailleur to use.

[@woodworks2123]

Good explanation. If you had a short cage derailleur and changed your cassette which would need a medium or long cage, could you solve the problem by just swapping the cage itself with maybe an aftermarket one rather than the much more expensive option of buying a whole new derailleur?

[@dcwad1]

Thank you dude.

[@antontkacz6693]

If you use a "linderets roadlink" you could use a 32 cassette with a short cage derailleur very usefull ...

[@sdolman79]

would you have to change the chain length when you do this for a 32 cassette

[@Aaron_Higgins]

I'm using an 11-32 with a dura-ace 7700 short derailleur, no road link. An 11-34 will actually fit but your chainrings will need to be very close in size, 36-46 would work. I may get a roadlink and go up to 11-36 soon

[@echtogammut]

Yes, your chain length is determined by the circumnavigated distance of you big crank ring and large cassette ring. In addition to adding distance by increasing the cassette size with a 32 from whatever you had previously, the roadlink adds a few more millimeters of distance, as it drops the derailleur further down.

[@Orgakoyd]

Harley is that you?

[@Aaron_Higgins]

Ha ha. Harley does have some good points about cadence, especially if you do nothing but mountains like him

[@Skooteh]

If you want to open up a huge can of worms, cable pull ratios and which you can bodge together. the official answer to most of these is "you shouldn't" but a lot of it does kind of work together.

[@xGshikamaru]

Shimergo ftw !

[@trike4]

jtek shiftmate device works very well to match different pull ratios.

[@moncarreon3043]

Hi, can you clear the issue regarding the compatibility of a road bike cogs to mountain bike hubs. Some says the road cogs need longer cassettes than the mountain bike cogs, i just experience it recently and look on discussion that justify my experience.

[@JustAnotherDayToday]

The vid could have gone a little deeper to go into the SRAM WiFli and Shimano long cage, what max cassette they can take and how to adjust the B-tension screw accordingly. Personally, my Cervelo S2 was ruined when I went to a WiFli 11-32. Big loss of power, even after getting the LBS to fully index, align the chain and tune shifting. None of my other bikes with short cage don't have this problem.

[@erxkeel]

good info.

[@joachimvadseth6414]

I run a 11-32/50-36 on my default Ultegra RD-6800-SS (short cage) with the B-screw all the way in, no problem. No need for a RD-6800-SS (long cage)

[@SidShetty]

hope someone can help me >< I have Trek FX 7.3 meaning 3 chain rings in the front and alivio RD on the back. but recently i changed the back cassette to a 11 28 T which is basically a road bike one since i don't go off road or trials with my hybird. now im currently using Stock which im assuming is Long cage RD can someone tell me if thats ok or if i shoudl shift to a medium one ? any help appreciated.

[@michaelsimpson2567]

Hello, I have a 12-25 8 speed cassette on the back with a Claris short cage rear mech and 50/34, the b-screw doesn't seem to do much of anything and the mech's pivot spring won't pull the guide pulley closer than about 20mm away from the big sprocket. I've read that you should get this as close as you can. Is it possible that the 25t is just too small for that particular setup or have the springs on my rear mech had it already? It's only been on there for about 1800 miles.

[@Clickitandfixit]

Of course this video comes out the week after I need it! lol

[@SaadKidwai]

Thank you

[@shaunhopkinson8667]

So, I'm little curious about this. My set up is currently 1x32 at the front and a 11x42 at the rear. This would give me a total diff of 31 wouldn't it? If that's the case could I have bought a medium cage Sram GX rear mech for smoother gear change?

[@CaiandtheMoose]

Is it a good idea to use a rear derailleur extender? I have a Dura Ace derailleur which is a short cage and has a maximum capacity of 11-30t. Instead of changing to an Ultegra to use a 11-32t cassette will a derailleur hanger do the job?

[@kaptajnklo100]

Wil it be possible just to replace the cage of the dereailleur (SRAM RED 2x10) to accomadate a 11-32T cassette or will the jockey wheel be to to close to the largest cog?

[@hutch430]

Thank you.

[@MuhammadFadillah1990]

If I use 58T chainring and 11-36T sprocket on my 20 inch folding bike, which RD that would be most compatible?

[@jordywilliams]

i installed a new groupset and made my chain too short. this means i can't use the smaller gears on the cassette when in the big ring, which is not an issue at all

[@saskaboh26]

I have 50/34 front and 11-30 back and long cage. I find it very hard to ride, esp. hills. Will there be a difference, if I put on small cage? Bike is Merida scultura disc.

[@SlowBoyAthlete]

Real Daniel Lloyd 1 returns to maintenance Mondays, we just need coffee culture music for the background like in the good old days.

[@jalalabdulmalak2506]

According to shimano Manuel the 105 5800 with short cage work with 11 to 32 rear gear. I switched from 28 to 32 with B screw tighten to the max and still have some ribbing . Any ideas

[@santiagocamilomartinezespi1165]

Could you please make a video of how to set up a track bike??

[@simonrano8072]

Seriously, there are 5 moving parts. If you really do track bike ask the other guys in the velodrome

[@B1r0d1M0n]

I'm pondering buying an canyon al 9.0 or cannondale caadx 105, any pros and cons? Recommendations?

[@soliranje]

Hi, I am running 3x10s on my MTB 11-36T cassette and I wanna upgrade it with 11-42T and keep my 3x10s. My rear derailleur is deore xt m781 sgs and in product specs I found it has total capacity 43T. So, will it work with my RD? thanks...

[@jrpzjrpz24]

I need help! I have 52t-42t And 11t-28t Cassette I bought a short cage Shimano Sora rear derailleur will it work?

[@madebyp90]

if use shimano, u can use 52/34, 32-11at short (what is sram can,t)

[@johnmichaelbalila5023]

I have a 50/34 crank and 11/28 cogs with shortcage Rear deraileur, if i change my crank to 53/39 i need to change my rear deraileur to long cage or not?

[@skv1991]

Thanks, very informative one! Added subtitles in Russian =)

[@fabiocastro5225]

If I want to use a 52-36 172.5 with 11-28 cages, the rear derailleur should be short cage or medium cage?

[@genjitakiya8316]

Im planning to buy slx rd and shifter. And there's midcage and long cage. And right now mybike is 1x 38teeth and 9speed sprocket 36teeth(the biggest one). And my wheelset is 26. What do you think should I buy?midcage or long cage.

[@georgejgilles.3999]

Nice info.

[@ujjvalchauhan6628]

GCN has the ability to make an apparently boring topic into an easy-to-understand interesting one.

[@joeanderson3423]

Nice video. Question: Scenario ... Only one front sprocket (30T) and rear cog set if 11T - 34T, 8 Speed. How do you make the calculation for Long Cage/Short Cage ? Or will either one work ? My understanding is ... you ignore the front. So the difference between the 11 and 34 is 23. So the max capacity needs to be 23 or greater, which most Long & Short cages certainly meet. What is your take on this ?

[@williamstevens2382]

I’m in a similar situation and assumed the same as you. Did it work out in the end?

[@jaceknows247]

I have a raleigh serengetti mountain bike with full suspension over 10 years old. I need a new derailleur. Does anyone have any idea what would be considered a good quality derailleur? My old 1 got caught in the spoke because I was in the lowest gear going uphill and it got close enough to the spokes that it got stuck in the spoke and snapped bottom gear and bent the metal and broke the plastic etc.😣 any help is greatly appreciated 🙏🏼

[@jazzfizz00]

I have a 11-34 cassette. Will this fit a mid cage length? I don't seem to be able to find a long arm cage length in the RD-R7000 I have. Many thanks.

[@beneyckmans20]

But let’s say I can’t go in my largest cog (like 32) when I’m in my big chainring I can go into my small chainring and I would be able to go in my biggest cog right? So if I’m not massively cross chaining it should be all good wouldn’t it be?

[@imaginehydreigons5377]

I have single 52t and 11-34t cassette with ss Claris r2000 rd. Will it work? Rd's max cog is 32t

[@NastyNatty48]

How do calculate the differential total of a triple crankset ratio?

[@rudolphvanthoff1391]

Can you please please please help. I have a 20” fat ebike and I am looking like an idiot pedalling so fast. I upgraded my freewheel to a DNP 11-28 and may order a 11-32/34 since I have installed this I have ordered a 54t 1x chainring to replace the 46t. It seems everything online is angled at 2x or 3x chainring sets and 26” wheels. The point? I have a Shimano tourney RD and wanted to know if when I upgrade to the 11-32/34 and the 54t chainring what might the requirements be for my derailleur? Should I go medium? Do I need to? The local shops cannot get their head around the cadence limitations of having a 20” wheel with ebike assistance and the requirements of such high gearing. They look at me like I am insane…. I don’t think I am…. Help please! LOL

[@n_ex___]

can anyone help me! my spracket is 11-46 and may crank are 48t and my rd camt handle it what do i do!

[@Startekselva]

keep post more videos like this

[@RicSil69]

Hi. Why does my rear derailleur hit the chain stay in all gears. Is this something easy to change? Many thanks

[@trike4]

GCN, great video as usual......I installed a "Roadlink" to save money when I went to a larger cassette with my shorty derailleur. Any input with using a Roadlink?

[@JS-tb9hu]

.

[@trike4]

Rear.....I went from an 11-28 to an 11-34. Front 50-34

[@leedorney]

36-28 - a invention that allows ya to use a 110 bcd c.ring on a 130bcd c.set and vice-versa would be good!

[@simonrano8072]

just use a 110 bcd you can still put 53/39 if you will

[@nivekvb]

Help! Shimano 11T - 34T cassette. Shimano 2-speed Front Chainring 34T - 46T. Any ideas for a Shimano derailleur, anyone, please? UK I can't seem to find one.

[@hayza7324]

is it okay that my rear derailleur is stretched i have a m8000 deore xt rd

[@harryallen457]

Excellent. Is this available in English?

[@kellymckenzie4865]

Why did you keep stopping the wheel with your hands when you had your hand on the lever?

[@Standard080105]

Why is it Shimano also quotes a minimum large sprocket size? For the medium cage (GS), this is 28T, as opposed to 25T for the short cage (SS). Surely, if the medium cage can cope with 11T on the smallest sprocket, why would it have difficulty with 25T as the largest sprocket size. Dan’s explanation in the video suggests this shouldn’t be a concern, and that makes sense to me. Nevertheless, Shimano does quote this additional specification.

[@niallchurch2679]

That's as clear as any mud you can think off!

[@4879daniel]

why didnt anyone tell me thats how you stop the rear wheel spinning when its in a stand, i feel so dumb for reaching around to the lever or trying to grab the tyre

[@thatsprettygood5121]

Can I use a 7 speed derauiler on a 6 speed cassette

[@googlelimp9834]

Ok so with the larger set you showed is that to a medium or large?

[@noxx838]

How to compute sir in single speed (1x8) setup?

[@ivanmiuller]

My ultegra 6700 has 30t on it. What does it mean. Any help?

[@clockworkchaos784]

I'm considering trying a set of Rotor Q-Rings... Does anyone know how would this impact the total differential? *(do you still calculate it off the nominal chainring size, or based off the theoretical min/max of the oval)

[@ricktan5663]

Based off the total teeth of the chainring