patent application drawings for Shimano shiftable narrow-wide double chainrings

With the advent of narrow wide chainring designs, we’ve gone from worrying about dropped chains to full on all mountain riding with nothing more than a bare single chainring up front keeping our chain in place. Sure, clutch-equipped rear derailleurs help, and more aggressive riders still use a chain guide on occasion. But for most of us, the alternating tooth profiles are all we need to keep things running silent and smooth.

The tradeoff, of course, is that these chainrings couldn’t be used in a double crankset since there are no provisions for moving the chain from one ring to another. Whether it was simply an assumption that it couldn’t be done or a lack of interest in better chain retention on a double (or triple, for that matter), it simple fact is it wasn’t on the radar. Now, thanks to Shimano, it is, and we’ve got some good ideas on where it could be heading…

patent application drawings for Shimano shiftable narrow-wide double chainrings

VitalMTB first spotted the design, then we got our hands on the full patent filing thanks to an anonymous tipster. What separates Shimano’s design from standard narrow-wide chainrings are several key features: Ramps & pins, spans of teeth without the + shaped wider tooth profiles, and shaping on some of the narrow teeth. The combination of those features create “Shifting Areas” on the chainrings that make it easy for the chain to lift off one and settle onto another.

The wide teeth distinguish themselves from other narrow wide designs by using more of a + shape than a fully wider shape. The patent application mentions this is done to save weight while maintaining all of the chain retention benefits.

As the image above indicates, they’re looking at using the design for both double and triple cranksets.

patent application drawings for Shimano shiftable narrow-wide double chainrings

Several different tooth shaping techniques appear to be key parts of the design. Among the wider teeth, some will be slightly wider than others depending on their position within or leading into the Shifting Area (see 32c below, at bottom of drawing, for example). The both wider and narrower teeth with have some with a slight wedge cut into it (32d). Among the wider teeth, the non-shifting teeth maintain a + shape, and the shifting teeth lose the inner widening strip to form a “T” shape instead. The patent specifies that these shapes are not the only ones that may be considered, with diamonds, trapezoids, triangles and hexagons also on the list.

The pins and ramps create supporting structures that help carry the chain up the inside face of the ring, spaced to allow two chain links to rest on the pins as it’s carried upward.

patent application drawings for Shimano shiftable narrow-wide double chainrings

While it’s not shown in the accompanying images, the patent does say these designs could be used in other layouts, which makes us think 1x drivetrains. While Shimano’s current offering’s lack of a narrow wide tooth profile hasn’t stopped them from offering distinct 1x chainring setups, we’re thinking this could open up an interesting opportunity to make one ring that works for both. Imagine having a double crankset where either chainring could also work perfectly fine as a single chainring, and you could simply flip-flop it’s mounting position to gain the correct chainline. Given Shimano’s typically high chainring cost, getting one ring to pull double duty could help justify the higher cost and add versatility.

The patent app also mentions that these shapes and designs could also be used on a rear sprocket. What will be particularly interesting to see is how they manage to get the chain to stay in sync as it shifts, landing the outer chain plates on the wider teeth.

The patent application was filed back in October 2013, published in November 2014, but just showed up online recently. We’ve reached out to Shimano for comment and will update if/when we hear back.

51 COMMENTS

  1. It doesn’t say so in the article, but you would think with the varing width of the teeth on the chain rings you would need a specific chain and you have to use that chain and that one alone.

  2. It’s about time, they should have taken the hint when none of the pros feel confident with the “tall tooth” ring.

  3. With the obsession with the front you do not need a clutch rear. I do not have a clutch rear nor do I want one so the ring is the best option. I have been using carbon front rings with tall teeth for years and have not ever needed a clutch rear.

  4. I’d not ride mountain (or cross) without a clutch derailer ever again. The peace and quiet I get from the lack of a chain grinding away the chainstay is worth the barely detectable ramping up of shift difficulty across the cassette.

  5. @colorblind – I’m right there with you. I want a Shimano road clutch option, please (if nothing else, for CX). I gave up SRAM a long time ago

  6. Shifting down to the small ring probably relies on the fact that the chain can’t actually settle down on the ring unless it is matched up with the teeth. Synchronization for shifting up to the big ring is handled with the pins, which only work with outer plates.

  7. So will this mean that the Shimano XC Pros on the UCI World Cup can finally ditch the chain guides on their XTR Di2 groupsets? That must be so embarrassing for Shimano. Definitely not good advertising for 1x chain retention…

  8. Maybe if you drive to the trailhead and don’t like to pedal on the flats you don’t want shifting chainrings. For those of us who actually ride our bikes fast, having a 40-28 ring option up front makes all the difference.

  9. endless has been working on this idea for 20 years, they will be the first to debut it and take credit for it. Give them props, it was their idea first.

  10. Can someone explain to me why you would need multiple narrow-wide rings? Narrow-wide is to keep the chain on rings where there is no derailluer to do so. If you have multiple rings, then you have a derailleur that will keep the chain on them. So what’s the purpose?

  11. I’ll second what Inspector Gadget said. Not everyone finds a 1x useful. My Cube has a 40/30/20 x10. I would never trade that for 1x. I get stump pulling low end for steep and/or slow sections, enough gear to pedal 30+mph, and tight spacing in between. 1x is great for people riding terrain with no variety. The rest of us need more gears up front, in spite of what current fads say.

  12. Shimano should continue to not listen to you internet pansy-trolls and continue to be a successful multi-million dollar corporation who makes products that you complain and then buy.

  13. i’ll never have front shifter ever again after switching.
    first i did it 1×9 years ago and now all my bikes (except my touring) are 1×10
    I ride plenty of terrain and ride plenty fast, still don’t need anything more than one front chainring.

  14. Just make an MTB worthy internal hub or gearbox that isn’t 2,000 bucks. Honestly, this bad chainline exposed drivetrain nonsense is ridiculous.

  15. I have to second what Frank said. If you have a well adjusted front derailleur then you shouldn’t drop your chain. If you have a double or triple chainring, then you want crisp shifting, not chain retention. I don’t get this.

    I am all for 1x drivetrains and narrow/wide rings if they work for you. My mountain bike has a 1×10 with Race Face rings and I have yet to drop a chain. My road/CX bikes have compact doubles up front and I can’t remember the last time I dropped a chain. I do however check my derailleurs almost every other ride to make sure the chain won’t drop.

    I don’t understand a narrow/wide set of rings on a bike with a derailleur.

  16. An overly complicated shimanoism that we don’t need. I used to bang on desk making the calculator jump after figuring out the limited range on 1X blah blah blah. Now I love it and I have never lost a single place in a race or been left for dead in a group ride because I ran out of gearing. I get whipped by lack of fitness like every other looser. Maybe when I get old and need a lower climbing gear I can go to a double to get my feeble ass up the climbs…. nah, if I am that weak I will just gear the single ring down for the climb and coast when I head down the mountain ’cause it won’t matter anymore who gets to bottom first.

  17. narrow-wide has been dropped by the pro… they all use small and hidden chain keepers.

    at the cx worlds, many sram riders, including the favorite to win the title, dropped the chain.

    sram xc racers are not even hiding the chain keepers anymore.

    it is 90% the clutch derailer keeping the chain in place. but if you really go fast it is not enough.

  18. moreover… 1x is only good for people that always always the same trail or bike park.
    real “mountain” biking– in the mountains lol– needs a double or better a triple.

  19. with all the tire size choices what’s the bfd on having more than a 1x up front? jayzus, sometimes we look like fickle lil b*tvhes

  20. Its hardly a chain guide if just the top guide is in place.

    For freeride, dh, dj, yes you will need a full chainguide. DH/FR because of chainstay length changes from long travel suspension, dj because frankly nothing will reliably keep a chain on besides a full guide.

    A top only guide usually isn’t more than 30 grams… A full guide is 200+ grams and a hassle to setup (but that setup is done once). A top only guide takes 5 secs to install… No big deal.

  21. I ride a 1 x 10 on the road to get to the “real mountain biking” here in Duluth. We’re going on 100 miles of trails in our backyard. So either pedal faster or get stronger why do you need a double or triple up front?

  22. I honestly think this is just a way for Shimano to C#$%block SRAM if they ever decide to do a NW 2/3xwhatever. I really see no need for it.

  23. “All that narrow-wide innovation in the last few years… This patent squashes that for multi-ring set ups.”

    ya sadly. same for many things. big guys will always crush the little guys with patents. heck most small guys cant patent worldwide anyway.

  24. After seeing all the 1X bikes out of commission in the 2014 Iceman because the narrow part of their narrow wide rings clogged with mud and derailed the chain, I am not sold on this set up for all conditions I race in. Also, seeing some companies like Scott spec-ing chain keepers on some of their narrow-wide 1X bikes makes me hesitant too. I am interested to see what Shimano does, if anything, with this patent.

  25. It’s a little ridiculous saying that a front derailleur is a necessity for riding real mountain terrain. Please come up to these mountains you talk about. You’ll find precious few locals who bother with a god forsaken front derailleur anymore. Either you can climb the pitch or you can’t. Don’t blame your poor bike.

    @Remy come on man, make that dirt jumper a singlespeed already.

  26. Lol Eric strava! Have you ever been on a real mountain? Even the pros ride doubles, and you and precious locals can get away with a single? Btw a mountain is at least 1000 metr high. Like mt tam is not even a real mountain.

  27. A single front chain ring is fine for riding in the mountains if you climb to the top and then immediately ride down. If, however you do any riding that incorporates steep climbs and flat sections you may find you do not have an adequately high gear for the flat sections.

  28. We might not need n/w chainrings, and Shimano may never even use them. But they are going to stop the inevitable by getting a patent so that if any other company thinks its a good idea, they’ll have to pay Shimano.
    Not all patents are great ideas or are ever used, but they stop others from using the technology.

  29. @Dub hey, no one said it’s easy, but instead of refining a system with huge inherent flaws, why not focus years of work helping the world by creating higher performance internal hubs or working with partners to create a standard size gear box. Heck, the’ve been producing Alfine hubs for years, you don’t think that could have been brought to a higher level by now? Even a rohloff which is pricey is not that pricey if you can get years out of it and don’t have to buy two shifters and derailleurs and multiple chainrings etc. Unfortunately, the initial layout for a rohloff has made it much $$ for my bike, or I’d have one in a flash.

  30. The big innovation here is the potential to run the whole drive train narrow wide.

    By doing so you can much better control the twisting of the chain through the jockey wheels when cross chaining, so that if Shimano go ahead with their 12 speed patents they will have much better chain alignment as the chain exits the top jockey wheel at the ends of the cassette where the twisting can cause poor running.

    It will also allow lighter action shifting by a lighter spring in a clutch derailleur.

    Bring it on.

  31. HAHAHA! To summarize the collective wisdom here:

    1. A 1x setup is the bees knees for some nobody, in his (or her) nowhere part of the world. Why a company would still sell a 2x setup is just stupid.

    2. A 2x or 3x setup works even better for some other nobody in some other nowhere spot in the world. Why Shimano would make a 1x setup is just stupid.

    3. The underlying logic that Shimano might want to be able to offer 1x, 2x, and 3x setup to appease all such nobodies in #1 and #2 above is completely beyond us here.

    4. We should all ride exactly what the pros ride.

    5. My mountains are bigger than your mountains, (deleted).

  32. I’m done w/ single 1 x 11 set ups. Too steep for long rides where I live. The first two hours I can handle it but after that it’s just a terrible sufferfest. Thank you Shimano. 2 x 11 is the way to go for me.

  33. My knock against the 1x drivetrains is mostly that in order to get a wide enough range to be useful, the gaps wind up being almost 20%.

  34. @Liasara by pros do you mean the 5-10% of the EWS pros still on doubles? But I guess they don’t ride mountains up to your specs.

  35. What if Shimano really likes narrow-wide for 1x but can’t use it effectivrly without paying SRAM, so they come out with 2x narrow/wide with the sole intention of being able to offer these chainrings without SRAM’s patent?
    just throwing some conspiracy theory out there…

  36. I love the small gaps offered by a double, but I think single ring set ups are still awesome in some situations.
    Oh and the dude has already won.
    I bet you the dude doesn’t even need to pedal.

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