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The Truth About the Shimano A and B Type Chainrings

Home » Equipment » The Truth About the Shimano A and B Type Chainrings

Although widely claimed that Shimano A and B type chainrings are interchangeable with an unnoticeable penalty in performance, in reality things are not as perfect. They say a picture is worth a thousand words so with actual photos I aim to show what is the difference between the two types.

Shimano’s front derailleur/chainring shifting is an industry standard. No grind, no hesitation, as soon as you move the lever the chain obediently and imperceptibly moves between the chainrings. Electronic Di2 shifting makes it even better. In order to do that Shimano, had actually machined “gates” and pins on the big ring to assist and “pick up” the chain.

In their search for perfection Shimano has taken front shifting a step further in their top of the line components – Dura Ace. Outer chainrings are available in two types – A and B.

  • Type B: by far the most popular one and also the default on Ultegra cranksets; it comes in 52 and 53 teeth and must be paired with 39 tooth inner chainring.
  • Type A: comes in 53 as well as 54 and 55 teeth; as per Shimano’s advice must be installed together with a 42 small ring.
  • Type E: a VERY rare combination: 56/44

There is NOTHING unusual about the 39, 42, and 44 tooth chainrings. It is the outer big ring that has special gates and pins machined into it for smooth and fast shifting. Since the 53/39 cranksets are dime and a dozen, flatlanders and time-trialists alike may opt for a 42 inner ring for tighter gearing. The more inquisitive like myself are aware of the A and B type Shimano story so we go on Google and search if it is possible to mix and match. And what do you know, the internet says it is, so it has to be true!

60% of the time it works every time.

Yes, but no! In short: 60% of the time it works every time. In my experience 3 out of 4 shifts were even better and quicker than with the 39 tooth ring – no surprises there, the chain travels a shorter distance. However, the horror is that 1/4 of the shifts that do not work as intended. The chain just sits in between the two chainrings and with a loud grind, it wrestles against the ramps and pins, until it makes the shift almost a full revolution later. It does this both during an upshift and downshift, although it is quite more pronounced when the chain is desperately going for the big ring. If you are doing the shift under even moderate power, or when trying to make a move and accelerate out of the saddle you can hit your knee(s) at the back of the stem, slam the top tube with your nether regions or even worse – tumble face first forward (although the last one takes a little more than a misbehaving chain). When seated during a time-trial this would cost you valuable seconds and can throw off your pacing.

At first I thought it was due to a slight misadjustment of the front derailleur, however, I experienced the “limbo” shifts on another bike with an almost new and clean Dura Ace 7900 directional chain installed correctly. As soon as I changed the 42 ring for the original 39, everything was perfect again.

Why???

Even the great Sheldon Brown doesn’t provide a reasonable explanation, so I got to searching and I finally came across a close up view of both A and B type 53 Dura Ace 7900 outer chainrings (thanks to eBay seller Mr_dura-ace for the pictures).

The Shimano A and B Type Chainrings

First, both chainrings have two surfaces: a darker colored inner one and a polished one where the teeth are. There is a circular “edge” going around the darker metal part.

Shimano A and B type Chainrings

  • The B type ring has 2 pairs of gates and pins, together with a single gate and pin between the two.
  • The A type ring has the “edge” much closer to the teeth and has only 2 pairs of deeper gates with a pin at the end of each one.

So what happens when you swap a 42 on your 53/39 B type crankset?  The bigger inner ring (such as 42,44) simple covers the “edge” so the chain would have to rely on the very shallow gates to direct it to the pickup pins. As I mentioned at the “right” moment and/or under power it will not work.

The A type ring addresses all of the above. That being said a 53 A and a 39 inner ring is not a combination I have tested.

Conclusion

Apparently the A and B type chainrings by Shimano are not just a marketing gimmick.  If you are to believe other’s opinions you can mix and match components without a penalty in functionality. Although installing a 42 inner ring on your standard 53/39 B type crankset would not be the end of the world, be aware than occasionally shifting might feel like a dropped chain. I am almost certain that 99% of sold units out there are your humble 53/39 B type so the cheapest/easiest solution for closer gearing is to switch only the inner ring and (learn to) live with it. Therefore most of the information regarding compatibility is assumed and misleading, be aware of that (when you are trying to diagnose where did the perfect Shimano shifting go after you changed chainrings).

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Home » Equipment » The Truth About the Shimano A and B Type Chainrings

68 replies on “The Truth About the Shimano A and B Type Chainrings”

Hi,
Just read your article, with special thanks given to me for the pictures you mentioned. However, you listed my eBay id incorrectly as MR_dura_ace, when it’s actually, mr_dura-ace.

nice article. I have a 52-42-30 Ultegra triple circa 2001. Each ring is clearly stamped with an A. Just changed my chain and have indeed worn out my second 42.

Thanks for you comment. If Shimano still offers a 52-A chainring at the Ultegra level it gives a budget option for a 52/42 setup.

Thanks for a great article 🙂 so will it work if you replace both chain rings on the front and no other components? ie if you were running a 53/39B and replaced both rings with a 56/44E, or do you need a new derailer and chain as well? Thanks

Hi and thank you for your comment.

If you change from 53/39 to 56/44 you will for sure have to raise the front derailleur a couple of mm and if your chain was the correct length to begin with you might cause your derailleur to be under a lot of tension (pulleys pointing forward rather than downwards) in extreme combinations like 56/25-28. If you are installing a new chain and you know you will be swapping chainrings like this make it so it fits the 56 big ring combination. Other than that you should be good to go.=)

Good luck!

Hi can I use a 53A with a 39B? Because I ordered them seperately and when they arrived I noticed one was A and one was B

Hi,

The 53A/39B is not a combination I have direct experience, however, I can imagine it will work well enough (like the 53B/42A), with the occasional erratic behavior/slipping/delayed shifting, all in all it will be fine. That being said, I am curious of your experience with the new chainrings.=)

I had a bad case of chainsuck (brand new chain installed) that knocked off my chainstay protector 2 weeks ago; I was riding my spare crankset that has the 53B/42A combination. However, I think it was because I sized the chain 1-2 links longer than optimal.

Hi and thanks for the info I decided to send the 53A back and get a 53B. When I checked my old ring it was actually a B so I didn’t want to risk mixing them up if it would lead to some mechanical problems as you said. Thanks a lot for the helpful info !

please help, I have a 53/39 to replace 50/34 compact on an internal cabled Giant defy. I want to increase the top end performance whilst giving me something to beat the climbs in the Bath/Mendips area. What rear cassette would work and how do I increase/change the internal cable length to allow the larger chain ring ? Ian Melksham

Hi and thanks you for your comment. To answer your first question, in my opinion 11-28 or 12-28 cassette should cover you for most terrain. As far as cables are concerned by switching to a standard crankset you will have to raise your front derailleur a bit. Usually there is enough cable so you should be able to do that easily. If the rest of your drivetrain/cables are in good condition you will not have to do anything else. If you are not comfortable working on your bike, you can bring it to your local bike shop. Let me know if you have other questions.

Best of luck with your cycling endeavors.

Have fitted larger chainring, complete with new chain but existing 12/28. Just enough cable to move front derailier up enough to clear chainring. Looks alright on the stand, but on road tomorrow so fingers crossed….Thanks for the advice. Rgds

The major difference between A and B chainrings that you have overlooked mentioning is the different alignment relationship between the mounting bolt holes and the teeth. If you compare an A with a B chainring by aligning up the bolt holes, you will observe that the teeth of one will align with the valleys in the other chain ring.
This is to ensure that during a gear change when the chain is in one ring on the top and the other ring on the bottom, the chain meshes with both rings. If a B Ring is used with a 42 inner, or an A with a 39 inner, this does synchronization does not occur, and the chain will sit on top of teeth of the gear being selected rather than meshing with it.

Hi and thanks for the insight. It is nice when somebody points out some of the engineering reasoning that goes behind the components we all use =)

I have a Dura Ace SG-X55A /42 chainring and 12/25 cassette. I get great speed on the flats but need help on the long hills. I was thinking of going to a compact 50/34 to help me with the hills. What are your thoughts?

Hi Mike,

Compact crankset definitely can help you up the hills and the gear ‘jumps’ are a bit closer together as you go through the cassette. In addition you won’t be missing that much on the top end, but having a 34 chainring will give you quite some lower gears. With the new Shimano 4 arm cranksets you can go the ‘mid-compact’ route 52/26 and if needed in future you can change the chainrings to any combination without needing a new crankset. I only have one comment which is relevant if you race – the 11 in the cassette is a must have, regardless of the front chainrings.

Best of luck with your cycling endeavours.

-Nikola

D-type chainrings suit some gearing combinations, not mentioned in the post. The new Shimano 4 arm cranksets have opened even more gearing combinations (52/36, etc.). I am planning to do an ’11-speed update’ of the post in the future. However, for the time being I am sure that mixing and matching D-type chainrings would have a similar effect as mixing A and B type – it would shift almost perfect in most situations with some exceptions, most likely under significant power.

Best,
-Nikola

I am a tall cyclist like you and have been reading you site with a lot of interest.
Over the coming winter I’m hoping to use the small ring more to get a higher cadence, however I’ve been running a compact which doesn’t really work.
To save costs in replacing both rings, I thought I’d be able to just replace the small ring so I’d be running a 50/39. Would that work or am I just being a cheapskate?

Many thanks

Jan

Hi Jan,

Thanks for the compliment, lots of changes and content coming to the blog soon as well. To your question: If you are currently running one of Shimano’s new 4 arm cranksets finding a 39 tooth chairing would be relatively easy. However if you are running the classic 5 bolt crankset, keep in mind that the bolt circle diameter (BCD) is 110mm for compact (130mm for standard). There are 39 tooth chainrings in 110 BCD, however, I am not sure on the availability. As far as compatibility I suspect that the 39 chairing being of larger diameter than the 34 would cover some of the ramps and pins on the big ring and maybe provide suboptimal shifting in some situations (ie full power sprint), where you should ease up a touch when shifting anyway.=) Besides that just ride what suits your goals and budget; I was just looking at the derailleurs that the pros had 50+ years ago. What we have is light years ahead technology wise so it will work fine.

Best of luck,

-Nikola

Hi, i have to change my 50 teeth ring on my Tiagra 4500 groupset and i was wondering if i can replace it with a 52 teeth chainring instead of the 50 that i have now. The other rings are 39 and 30 teeth and it’s a nine speed transmission.
Will a 52 chainring from 105 or Ultegra fit ? Will it have to be a chainring from a triple 9 speed transmission or it will fit with a 52 plate from a 2×10 or 2×9 drivetrain?
Thanks !

Hi Bogdan,

First thing you need to know the Bolt circle diameter (BCD) of your current crankset. I suspect it is compact (110bcd). Any chainrings need to be 110bcd in order to fit. 105 or Ultegra that have 52 teeth are usually “standard” size which means 130bcd so they will NOT fit a compact. Whether they are 9 or 10 speed this is largely irrelevant and even though manufacturers recommend against mixing, they work quite well.

Best,

-Nikola

Hi. Thx for the answer . I forgot to mention. I’d 130 BCD . I have the options of FC 5502, FC 5600 ,FC 5700. Which one would be preferable ?

Hi, I have an old crankset; it is a Shimano Rsx A-416 with 52/42 chainrings A-type.

I would like to change the inner chainring (42t) with a 39t.

I can’t find a Shimano A-type 39t inner chainring. 🙁

Can I mix the outer chainring 52t A-type with an inner chainring 39t B-type?????

Thank you.

Hello,

As mentioned in the article it is the big chainring that differs between a and b type. You can mix a and b types though in some (emphasis on some) situations the shifting might not be 100%, though it will be good enough. You should be fine with 52a and 39b.

-Nikola

Hi. Thanks for the article. Wondering if you can help me out here: I have a Shimano SG (superglide) chainring saying A53/, on an 8 speed cassette. Is it possible to convert the chainring to a triple by adding a 26 or 28 ring? And if so, which rings would work? Rest of the gearing is shimano 105. (Have the feeling that it is a non-convertible duocrank, but the bike is not with me at the moment, so cannot even try it out). Best regards from Signe

Hi Signe,

My bet is that it is a double only crank. If it is a triple you will have extra set of holes for the granny ring. Other than that, I am afraid besides a totally new crank, you are out of options.

Best

Actually, not quite out of options. There is a middle ring called a “Willow tripelizer” that will let you bolt the inner ring to the Willow tripelizer middle. You would probably need a longer bottom bracket axle too.

hi there, I have an ultegra 10 speed groupset.6700 sg x type b. 53/39 standard. I want to upgrade to a 54 or 55 chainring for tts. In your opinion what is my best/most reasonable option? Could I put a type A 55 dura ace chainring on? Understanding the above article that shifting from a 39/55 wouldn’t be ideal. I assume this wont be a problem considering the tts are flat and I have a separate warm up bike therefore could actually retire the 39 if need be.

thanks

Hi Sean,
As long as the BCDs match you will be able to mix and match chainrings. 55/39 combo would be at the limit of 16 teeth of the front derailleur so in theory it will work, as I mention some shifts might not be the greatest and you might have to ease up to aid the chain going small-big.

In practice though, 54/55/56 big chainrings are not necessary in my experience even for TTs. Unless the courses you ride have lots of downhill sections and/or tailwind. A rough equivalent is 4 teeth at the front equals 1 tooth in the rear so you are gaining half a cog. Of course your cadence, power output and as I said course profiles should be your guide. I used to run 42/54 (also as Osymetric) though now I just have a standard 53/39 I use for everything, simplicity and less stress before/during my raceday preparation, it is quite nice.

SRAM 1x systems are definitely something I will try (I have a gravel bike in the making) and 50/52 single ring for time trials is a thing I see myself experimenting with – it would save couple hundred grams+possibly better aerodynamics due to no front mech/hanger. Cassette choice in my opinion is much more important, though 11-28 is set and forget for your race wheels, even with massive crosschaining, modern systems behave quite ok and you won’t have to shift off the big ring. Go out there and have fun and don’t be afraid to experiment.=)

Good luck!
-Nikola

Thank you very much for the detailed response. I have also enjoyed reading some of your other articles. So a double thanks in essence. I agree with your tt concept of not needing bigger than a53, however a few course, the nationals in particular last year had ‘rolling’ terrain and very windy sections that may have suited a bigger gear. Really it’s more of a little project occupying some time and tinkering with set ups. I hope to do a few triathlons this year therefore the downhill pedalling will be a welcome addition if I get this right. Really, I should probably work more on my cadence rather than looking to spend more money on bikes!

You make a very valid point about the redundancy of the smaller ring and derailleur/shifter cables etc to save weight/aero dynamics, And the peace of mind that you aren’t going to have front mech probs again. The only thing we have to worry about is the legs not working!

Thanks for your time.

Regards

Sean

Hi Sean,
Thank you for the nice words. It took me a while to make sense of all the contradictory (and sometimes) plain dangerously wrong information (nutrition is especially rife with that) out there and with the articles on the site I want to help others.

About chainrings…some courses like you mention will require bigger stuff (55-56), for example a mostly downhill TT in the US Pro Challenge in Colorado one year had teams scrambling for the 56t rings, though I have spun out (120+rpm) the 53-54/11 once…maybe twice and at those times I think I was better served coasting to recover a bit for the following sections. I think it is better to train riding at 100-110 rpm cadence sustainably rather than taking the shortcut of buying yet more bike stuff hehe. Triathlons are a bit of a different game and a lot of triathletes cruise at 80rpm since you have to run afterwards. Jordan Rapp uses a 54t SRAM 1x setup for that reason. Again course profiles, riding style and conditions can vary in the extremes so ‘one-of’ gearing combinations might be needed. If my powermeter wasn’t 130BCD, I would just have a 52/36 and call it a day (it would also make it easier to put 38/42/50 1x setup; now I need to buy a second crankset with 110BCD). Shimano has it nice with their universal bolt pattern for both compact and standard cranks, let’s see when SRAM releases something similar.

A little known fact is that the original K-edge chain catcher was made for Kristin Armstrong for the Beijing 2008 Olympic TT where the course required shifting between the front chainrings. Nowadays we take such devices for granted.=) The single front ring is not a new concept, though the technology to make it reliable is a recent development; so it is worth a try, without risking losing a chain in an inopportune moment.

Good luck with you TTs!
Best,
-Nikola

HI there I have a question I have a Dura Ace 53/39 crank and I am thinking to replace the 39 chain ring for something smaller if is possible if I have any options or if I have to change the 53 for a 52 for more options?

Hi Juan,

That depends on which model Dura Ace crankset you have. If it is the 5 bolt older model (7900 or earlier) the smallest chairing you can fit is 38 teeth (not a noticeable change so I will not bother) – the bolt circle diameter is the limit (130 mm vs 110 mm compact). On the new 4 bolt pattern cranks you can fit much smaller ones though the thing to consider here is front derailleur capacity – in simple terms most derailleurs support a difference of 16 teeth between chainrings (53/34 = 19 teeth). Anything bigger would defintely cause some weird shifting and most likely dropped chains. If you have the new 4 bolt cranksets i would look into changing both chainrings to 52/36 or 50/34, even 46/36 (not the cheapest option, though you don’t need a new crankset). In my experience compact (50/34) is what most people should be riding. Those chairings come in ‘pairs’ with matched ramps and pins to further imrpove shifting (as discussed in my article =) ).

Good luck!

-Nikola

I’ve worked on 38s on 130 mm crank spiders. They work well for a while, but as the ring and chain wear, the chain will skate over the nuts that fasten the rings. One tooth out of 39 is not worth the mechanical issues.

I have a 20 year old bike with Ultegra 53/39 B chainrings. 9 SPEED. I can’t find replacement parts anywhere. Any suggestions? Is there a compatability chart that shows what Dura-ace parts might be suitable. Seem to be more Dura-ace online than Ultegra.

Again need 9 SPEED.

Hi John,
Before Shimano (and other manufacturers) went to the 4 bolt asymmetric bolt pattern on their cranksets, most cranksets used chairing with a bolt circle diameter (BCD) 130mm. The 53/39 of your Ultegra have the same specification/BCD. So your best next option would be Shimano Dura Ace 7700 chainrings, or even 105. However, as I mentioned *any* chainring with a 130mm BCD should fit; whether it would match perfectly aesthetically, I don’t know… though you can try looking for Stronglight, Miche, Specialites TA chainrings and see what they have to offer, they must have a 53/39 chainrings in 9 speed. Last resort, 10sp or even 11 sp ones can work. Obviously with ‘non-Shimano’ parts, we are led to believe our bikes would not function very optimally – in this case there are way too many variables to consider, though non-ramped and pinned chainrings have been around for a looong time and worked well enough. Do not overthink it – people even today still use downtube friction shifters (even on 11 speed) with good success. Also older generation Shimano chairnings (pre-hollowtech II,so I think 7-8-9 speed, etc) were not as extensively machined (as compared to 10speed and anything after electronic gears came into being) to aid shifting.

Best,
-Nikola

Hello. Very interesting reading. I have an old LeMond Buenos Aires with a B type 53/39 in front. For me the gearing is too tall so any kind of hill is a big slow down and on level ground I don’t use the large ring at all. Would replacing my 12-25 with a 12-28 (or other range) be an effective fix? The cassette is a 9 speed. My bicycle knowledge is pretty limited, so finding your site has been a big help. Thanks. Joe

Hi Joe,

Thank you for your comment. I had the same challenges with hills as you and indeed changing the 12-25 for a 12-28 certainly helped quite significantly, please note anything bigger (ie 11-32) might not fit your rear derailleur/frame. This (12-28) is the easiest (and cheapest) fix, you can even do it yourself with only 2 tools (lookup a video) =). However, if you are rarely using the big ring, you can look into the so called ‘junior’ cassettes such as 14-28 (those are usually special order, though Shimano does have them, not completely sure in 9-speed) where the gaps are smaller and would give you some access to lower gears even on the big ring. The better solution would be changing you crankset for a compact (50/34) or 46/36; manufacturers finally understood that even pros don’t need 53/39 every day and rear derailleurs are actually designed to accommodate cassettes such as 11-32, 11-34. With the above being said if you want to keep your bike 9-speed, 50/34 and 46/36 might only be available in 10/11 speed group-sets (or non brand mix and match, such as Miche, Specialites TA, Stronglight ie not Shimano/SRAM/Campagnolo) so getting the shifting to be 100% *might* be a problem, though in my opinion it would be more than adequate. Aesthetics might not match.

Obviously it is very easy spending other people’s money=), however, with options at even Shimano 105 level (fanciness/price goes as follows Dura-ace>Ultegra>105 in Shimano), components are VERY good these days so for not a huge investment you can get a complete new 11/12 speed group-set designed to work with much lower gearings – at the very least 50/34 and 11-32. You can mix and match Ultegra(crankset/cassette) and 105 (everything else such as brakes, etc) for even lower 46/36 and 11-34. It gets even cheaper if you install everything yourself, even after buying the correct tools. You mention your bicycle knowledge is pretty limited, don’t let that stop you hehe, I have been there myself as well; Online you can find a TON of videos to help guide you, if not your local bike shop for sure should be able to help you.

Things get trickier if you have more than one bike and you switch for example wheels in between, or if your wheels are not 11-speed compatible….

This is all I can tell you with the information you have given me, so let me know if you have further questions if I have missed something.

Best.

-Nikola

I have a 1991 Trek 2100 pro totally stock with very few miles when given to me about a year ago.

It has the Shimano 105SC groupset with the FC-1055-SG chainwheel w/53×42 SG chain rings. It has the stock 13-28 7 spd cassette.

I’m considering replacing the 42t ring with a 39t to give me a little more for steep hills.

In the 1991 Shimano Dealers Manual (link below) there does not appear to be an A or B designation to either the 105 or Integra chain rings nor is any A or B destination is stamped my existing rings. Also in 1991 the 39t ring only existed as the Dura ace type B ring.

https://vintagecannondale.com/cannondale/shimano/1991%20Shimano.pdf

So my questions are:
1) Would a 39 type B be compatible with the “undesignated” 53? Front ring shifts work perfectly as is.

2) Specifically would a SG-X 10S 10S 39-B expect to work well ? (I already snagged one but don’t really understand the distinction between SG and SG-X and recently realized the 10S likely means 10 speed rather than 105 so this likely won’t work. I have a cn-hg70 chain.

3) Or should I pursue a matched 53/39 type B set

Thanks

Hi Bob,
As far as I am aware the A and B type designations are a relatively ‘recent’ development of Shimano – I think starting around the Dura Ace 7800 (10-speed) groupsets. What I mean by that is that before that chainrings did not have any very special profiles and did not really need matching. Even so, the inner chainrings do not have anything special about them so you can mix and match, no problem. Also as my experience that I describe in the article, even a ‘mismatched’ pair works very well in almost all cases. People run 10/11 speed with downtube friction shifters and it works just fine. I suspect replacing the 42 with 39 tooth inner ring, would work no problem.

In your case having a 10S chainring, since you already have it and can’t return it, might as well try it; anything majorly incompatible should be very obvious as you test it on the repair stand (possibly the chain rubbing the big chainring on the 39/13 combination, which is to be avoided anyway =) ).

Best,
-Nikola

Hey there I am fixing up my dads old bike. The chain is missing and I’m not sure on how to replace it or find a chain for it. From the looks of it , it is a shimano-sg 53 type B. I counted all of the spikes on the chainrings and came to that conclusion.

Hello,

Chains are usually sized according to the nubmer of cogs in the rear gear cluster (on the back wheel) – for example 9, 10, 11, 12 speed etc. Any brand chain designed to work with the nubmer of cogs on your dad’s bike should fit.

Best,
-Nikola

Hi Nikola, I’m trying to restore my 9 speed 2002 Trek 5200 , from its aggressive 53/39 11-25 to a more compact setup for long distance. Ideally it would be nice to keep it all Shimano, and run 50/39 on them, i’m just wondering if this would work even if its a triple ring, still 130bcd and 5 arm? https://www.ebay.co.uk/itm/SHIMANO-105-FC-5703-50T-D-CHAINRING-130mm-BCD-5-ARM-OUTER-CHAINRING-BLACK-/164201182192?_trksid=p2385738.m4383.l4275.c10 . With the rear cassette i was thinking to use a wolftooth adapter to increase the range to 11-32 or just use a Shimano MTB cassette. Do you reckon this will work?
Cheers
-Guy

Hi Guy,

Honestly when it comes to Shimano/STI triple chainrings things are a bit specific there as Jan Heine mentions in this article here (https://www.renehersecycles.com/trouble-with-sti-triples/), I have no direct experience there. While the chainring you linked is 130mm BCD so it will bolt up just fine, I am not sure if the ramps and pins would work as intended and it would shift fine, I really have no idea. I don’t think it will be problem though as I said I have not tested it, I am careful to recommend it.

As far as using an 11-32 rear cassette, older generation (pre-r9100, r8000, etc) rear derailleurs simply do not have the geometry to physically shift to anything bigger than 28 (possibly 30 teeth) so a Wolftooth link should go around that (pun intended). By simply using a MTB cassette you would run into the limitations.

In my opinion (and it is easy spending other people’s money) the modern 50/34, 46/36 +11 speed cassettes that go down to 32/34 give a LOT of useful gears and nice spacing for normal riding, long distance, randoneering etc. and you don’t have to change the crankset if you want to change chainrings for different events, etc. Even 105 level is pretty high quality at not a lot of money. Junior cassettes (Ultegra level usually) that are 13/14-34 are absolutely perfect for long distance. You can also build them yourself by buying individual cogs, though final price is a bit more than a full cassette. Also Miche has cassettes that use individual cogs all around so you can make a truly personalised ratio gear cluster. You can run an 11-speed cassette on older 9/10 speed wheels by removing a cog and a spacer and putting the spacer *behind* the cassette so you have 10 gears and one unused ‘click’). OF course all those ‘modifications’ can add up so if you are on a budget, a wolftooth link+50 tooth or even something like 46 (non Shimano 130BCD) chainring is an option.

Ps 1x setups are a step backwards here since they are neither lighter nor simpler, nor provide useful gear range/jumps, though they seem to be all the rage now so they do deserve a mention here.

All the best and let me know what you come up with,

-Nikola

I had a similar issue with my 2002 LeMond Buenos Aires (made by Trek). The original triple chainring already had the smallest ring removed when I got the bike. Found a Shimano “B” 50T chainring that matched my “B” middle ring and paired that with a Miche 14-28 9 speed rear cassette. This has worked pretty well for me with the caveat that I live in Florida which is practically without hills. Good luck. Joe

Nikola,

I’m wondering if you know of what I could get to replace my chainrings on an 9 Speed Triple Shamino SG A-52-42-30 with 130 BCD. I believe these chainrings are Ultegra. Struggling to find something that would work with it. Need to replace Chainrings, cassette and chain. Thank you for your help!

Hi Ryan,

Shimano/STI triples are a bit of a strange beast, as i mention in my comments a bit above this one, though in my opinion the best bet is to look for used or new old stock (NOS) parts on eBay, etc. As far as the cassette and chain, those you can still find new in quite some online bike shops, or eBay as well. Though how worn are your chainrings really? Do you need to change them? Do the teeth look like shark teeth? I think the 30t small ring is Shimano proprietary BCD (it attaches to the middle ring) though I find it hard ot beleive it is so worn as to need replacement?

Best,

-Nikola

So, did you ever figure out why 40 percent of your front shifts were ending up with the chain riding between the chainrings? Because if that happened on my bikes, people would stop riding with me. Or I’d give up multiple chainrings.

Hi there,

I never mentioned (or had) 40% of the shifts between the front chainrings ending up with the chain riding between the rings. I used the “60% of the time it works all the time” as a metaphor. In reality it was 1 out of 4 shifts that was ‘weird’ with once I actually getting massive chainsuck that took out the frame chain-stay protector on a carbon frame. Even so the suboptimal shifts were just clankier/noisier than compared to the superbly quick and solid chain pickup on matched chainrings (I had to ease up for a bit). The thing is Shimano’s matched chainrings, set the bar VERY high and they shift amazingly well (they kinda have to, especially with electronic shifting) and all other brands are playing catch-up. I have not ridden all brands though on an average day for example SRAM Red shifts more or less like the ‘bad shifts’ with the 53/42 mismatched combination. So it all depends what your benchmark is…. Besides the chainsuck accident (I had to stop) it never really was a problem or made my riding (or that of my riding buddies) any less enjoyable.

Why did they shift like that? Somebody in the comments above did mention something about the ramps and pins being clocked 90 degrees differently between the A and B combinations. Though besides Shimano, probably nobody really knows the full answer (otherwise other brands would not have such trouble making it work…).

And the last point above giving up multiple chainrings, the whole 1x thing *in my opinion/experience* was a bad industry joke that people actually took seriously… I have had a chain-drop on EVERY ride for the 1 month I gave it a shot and I couldn’t sell my 1x setup fast enough afterwards….that was annoying for sure. I did believe the hype about those 1x setups as well, so I wasn’t trying to make it not work… In the end it wasn’t even lighter and cassettes that are bigger than the brake disc look weird (bikes have to look fast, right =) ) . As they say “Your mileage may vary.” hehe.=)

Best,
-Nikola

You described your missed shifts as under full or moderate power, and sometimes standing on the cranks. Tell me if my impression is incorrect. The reason I am bringing this up is because I hardly ever miss shifts, regardless of the chainrings or brand of drivetrain that I use. Well, there is one kind of shift that i used to miss almost regularly, but since I stopped doing that it hasn’t happened.

Hi there,

Thank you for the reply. Though I do not seem to understand your question/points. I never mentioned missed shifts (like completely not being able to make the chain change chainrings) in neither the article nor the comments below it. I gave worse case scenario (hitting your knees at the stem when the chain drops, it has happened to me many many years ago on a misadjusted front derailleur) what could happen *IF* I was accelerating hard out of the saddle when the chain was riding in between the two chainrings. With that being said if I get a weird front derailleur shift, my natural reaction is to ease up and that usually fixes the problem. If I were to muscle through it, yes it potentially might not be pretty. The problem that comes with that is that I have to change my riding to accommodate that – for example trying to jump away from a group of riders in a race, etc., I wanna make sure I do not require a front shift since it might bite me. Though I don’t race anymore, so for me, this is a purely theoretical example. Anything other than matched Shimano chainrings shifts suboptimally *in my experience,* though as I mention I am far from being ridden most of the stuff out there (even Osymetric rings shift Okish). Overall moving a chain couple of millimeters side to side is not rocket science and it works satisfactorily even with mix and match component situation, with downtube shifters, etc. Some (Shimano) do it way better than most, so that makes the rest look worse, even though they shift satisfactorily, it’s a matter of where your reference is. I wondered wheter this was just hype or there were real technical reasons for it. As I did the research for this article it became obvious that Shimano has really done their homework (ramps, pins, etc) and they continue to do so (there are currently 5 matched chainrings combinations for road and another 1 for gravel – GRX. The bike industry keeps moving forward and I have long since stopped trying to keep up, so both my mileage/experience and yours in the world of front derailleur shifts may vary hehe.=)

Best,
-Nikola

Years ago our shop sold an Ultegra 6700-equipped Trek Project One Madone to a young lady, a triathlete. She rejected it because she couldn’t get the front derailleur to shift under full power. We even gave her a free upgrade to Dura-Ace. No change. If anything, it was a little worse. Dura-Ace 7800 was probably stickier than Ultegra. We ended up refunding her money and selling the bike as used at our tent sale.

I bring this up because shifting on the chainrings simply can’t work under full power, because of chain tension. The harder you’re pushing on the cranks, the harder your front derailleur has to work to push the chain off on ring and onto the other.

The rear derailleur has it easy. Chain tension is always moderately maintained by the springs in the derailleur. But between the cassette and the chainring the chain tension is controlled by your pedaling.

So my takeaway is, shifting chainrings requires a modicum of planning and finesse. Shift where you can momentarily back off on the cranks and give that derailleur some help.

Hi there,
I totally agree that some finesse goes a very long way though with electronic shifting, particularly Di2 you can power through a front derailleur shift (Di2 also overshifts slightly and later corrects back to the ‘normal position,’ besides simply having a lot more power/leverage). Even then there are optimal parts of the crank revilution to do it. Obviously ramps and pins help significantly. Should you be shifting under full power at all, hey it’s your ride, experiment and see what works. None of this is new, friction shifters forced you to do that, though I have ridden them only a couple of times and the rest is what old-timers mention time and time again.

Also you mention you replaced Ultegra 6700 with Dura-ace 7800. The upgrade for the same generation was Dura Ace 7900, so if it is not a typo, 7900 had a particularity that the front derailleur had no trim positions (at least in the big ring if i am not mistaken) so that means some motion/geometry sacrifices might have been made, though only Shimano knows the full story.

Best,
-Nikola

7900 had problems but for four years it was the most popular drivetrain in pro racing. I’m sure if it were patently defective we would have heard about it. My point is, reduce chain tension between cassette and chainring to facilitate trouble-free shifting and reduce wear and breakage of drivetrain components.

Hi there,
7900 was my first ‘nice’ groupset and in my experience (except the occasional mix and match scenarios I mentioned in the article) it worked just fine until i crashed it years later and rendered one of the hoods completely useless. For some reason people ‘in the know’ like to trash 7900 as a Shimano failure, though I never really had any issues and as you mentioned PROs rode it just fine; the original SRAM front shifting was something that is universally acknowledged as bad and no technique could get around the flexy titanium FD cage. 38t on 130mm BCD is bit of a band aid (as you mention on some cranksets the chain actually wears the spider!), especially nowadays with 32/34 rear cassettes. Overall besides stock shortages due to the Covid pandemic, it is a great time to ride a bike when it comes to quality and component choice!

Hi Nikola,
And now for something slightly different! The changing technology has put those who use triple cranksets in a pickle since road triples are all but discontinued! I ride an ICE Sprint recumbent trike with Deore 48/36/26t rings, 11-34t 11spd cassette & MicroShift bar end shifters. Climbing grades with a 30lb+ ride necessitates using a triple with granny gearing, while retaining taller gearing for downhills and flats.

The solution for me is a road triple with 53/42/30t. Anything less isn’t worth the cost to upgrade. Oh, must mention I’m using the shifters in “friction” mode. Fine tuning won’t be an issue. I just purchased “pre-owned”, a Shimano FC-6703, 53/39/30t B ring crankset, FC-5504 with 53t (aftermarket)/42/30t A rings & a FD-6703 derailleur. You can guess where I’m going with this. I’m thinking the bar end shifters will solve the “chainsuck” issue because it’s not an index system.

I’ll post an update in about a month, when i finish & test the systems performance.

Hi Tim,

I have done plenty pf gearing calculations (more than I care to admit) and while a triple crankset was a good option back in the day when rear derailleurs barely cleared a 28 cog, nowadays, with the availability of 46/31 or similar sub-compact cranks and road/gravel derailleurs that happily clear 32/34 cogs in the rear, triple cranksets really are not needed. What I would like to see getting more traction is cassettes with “junior” gearing (ie 14-28) becoming more standard as well. Even so, making a custom cassette yourself is (at least with 9-11 speed Shimano) not too difficult since for 99% of the riding most people do, even professionals 11-13 tooth cogs are rarely needed. Sadly though, the 1x ‘joke’ is being actually seriously taken and we se freehubs change to accommodate 9-10 tooth cogs.

All in all i am still curious how your experiment turns out.

All the best,
-Nikola

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