Besting Best: Dura-Ace 9100 Mechanical

Besting Best: Dura-Ace 9100 Mechanical

I’m an avowed modernist. I’ve liked both new and better ever since I was a kid. The march of progress appeals to me like the spring sun. How can you not like stuff that works better? Maybe that’s why I’ve found myself as a reviewer of things. From records to wines, I’ve reviewed all sorts of stuff over these far too many years. And over the last 25 years, I’ve had the opportunity to encounter each new iteration of Shimano’s top road group, Dura-Ace.

So that thing where I said I was an avowed modernist? I lost the plot line of my own life when Shimano introduced STI control levers with Dura-Ace 7400. I thought they were silly. I didn’t think they were necessary. I didn’t think they were better. I like better, so maybe I wasn’t going so much against my own grain. Those levers were heavy and made the front end of the bike feel sluggish. And you needed the ability to crush tin cans, not aluminum ones—like Quint in Jaws—in order execute a down shift in the rear or upshift the chainring.

But with each new iteration, Dura-Ace improved. Shimano has added three cogs, usually improved the braking, and vastly improved the ergonomics while decreasing the force necessary to shift. And in several decades of relentless evolution the group has lost more weight overall than those initial control levers weighed.

And so now we have the newest edition, 9100. Unlike the jump from 7800 to 7900 with the two ten-speed groups, 9100 doesn’t feel like a misfire. Sure, it didn’t add yet another cog, which was the hallmark of new Dura-Ace groups for more than 20 years, but nothing about this group is worse than its predecessor. Better, at every turn this group tweaks the best features of 9000 for just a little bit improved performance. Let’s take the group component by component.

Front derailleur
There have been few groups in history where the front shifting was one of the most important gains in the group’s performance. Dura-Ace 9100 ditches the long parallelogram of the previous front derailleur in favor of one that is much shorter, giving the entire derailleur a more compact appearance. More surprising is the addition of a new plastic cap on the top of the derailleur that helps route and hide the front derailleur cable. Most surprising is that for the first time in history a component manufacturer has included a way to adjust cable tension directly on the derailleur. Why is this just now a thing?

I had to watch a video on YouTube to understand the derailleur’s setup and had to fiddle a bit to get it right, but next time will be easier than Pi. I love the no more bending of the remaining cable to keep it from curb feeler-ing (technical term) the crank arm (or worse, your shoe).

Rear derailleur
The new rear derailleur sports a carbon fiber cage, a first for Shimano, but more important is how the design borrows from Shimano’s Shadow rear derailleur. The direct mount design is said to offer superior alignment while reducing the opportunity for either frame or derailleur damage in the event of a crash. I’m just praying I don’t have the opportunity to verify this first-hand. The cage had to be increased in length a bit in order to accommodate the new 30-tooth cog available on one of the cassettes. And rather than enter the derailleur straight in from the rear, the cable now enters at an angle

For the first time in more than 10 years Shimano has noticeably shortened the stroke of the small paddle behind the brake lever. Reduced by 14 percent relative to 9000, the 9100 levers have a stroke that is reduced enough to be readily apparent. More significant is a 24-percent reduction in lever throw for the large lever (the brake lever). I hadn’t recalled the reduction as I was assembling the bike with the parts, so my first ride served as my news flash that shifting was faster due to reduced stroke length and decreased force. Lever pull remains unchanged, so you can mix these with previous Dura-Ace parts. Brake reach has been made even more adjustable. The hood material has been changed to offer improved grip.

When you look at the brakes what is most visually striking is how much of the mass is oriented parallel to the rotation of the wheel. Shimano reports that these new brakes are 43 percent stiffer than the previous calipers. What I can say on a more subjective basis is that the increase in braking power is unmistakable. What that means is that you don’t need to pull as much to feel modulation. For everyone who thinks that caliper brakes have room for improvement that can save them from buying a new bike with disc brakes, these are the best caliper brakes I’ve encountered other than the Cane Creek EE brakes.

And while I’ve managed to fit a 30mm tire in the 9000 brake, Shimano increased tire clearance in this new brake to, as they put it, accept 28mm tires. There’s certainly room for tires larger than that. The orientation of the brake quick release was changed so that it tucks into the caliper arm. Should you need to open the brake on the fly to accommodate a wheel that’s out of true a bit more effort will be necessary.

This is one place where I have to admit that Shimano’s gains are utterly lost on me. The Hollowtech crank arm is now broader to increase stiffness and the outer chainring has been stiffened to improve shifting. I simply don’t produce the wattage necessary to notice the difference. Shimano’s front shifting has been the industry standard ever since the introduction of 7800, the first group that would allow you to shift from the small chainring to the large chainring while out of the saddle. The funny thing about this is that it’s a feature I don’t use as much now that I run a compact crank. A 16-tooth difference between large and small rings means that when I shift to the big ring I must immediately downshift two cogs in the rear, at minimum. All that said, for riders who produce big power and tend to mash gears, these incremental changes will make shifting that much smoother and foolproof. And while Shimano continues to offer 53/39 and 52/36 combinations, the logic of a 50/34 setup seems tough to beat if you’re not a pro.

So the big news on the cassette is that Shimano now offers an 11-30 cassette. That seems like a gigantic spread for a road broup until you actually look at the cog arrangement: 11, 12, 13, 14, 15, 17, 19, 21, 24, 27, 30. I can say with a straight face that I really don’t even miss the 16, and I’m a guy who used to look down his nose at cassettes that didn’t include both a 16 and an 18. What’s really intriguing in the Shimano catalog are the options of 12-25 and 12-28 cassettes. Were I still racing, the opportunity to ride an 11-speed 12-25 would have caused my brain to incandesce.

After thousands of miles on the 9000 Dura-Ace, I was wary of how much of an improvement 9100 could represent. Out of the box it looks like different cosmetics and not much else. And except for the front derailleur, as I assembled the group I found myself thinking that the group was nice, but not any sort of quantum leap.

Then I rode it.

The improvement in braking and shifting and the light feel of the operation of the group in terms of chain and bearing tension means the bike rolls with an effortlessness that is truly remarkable. Would I sell 9000 to upgrade to 9100? That would depend on my tax bracket. However, for anyone who has skipped a generation or two of innovation, be it Shimano, SRAM or Campagnolo, this generation of Dura-Ace is worth the investment. Who knows if Shimano will offer another group with caliper brakes? I wouldn’t be surprised if this was the last one; five years from now how many top-end road bikes will be sold without disc brakes? I can’t imagine too many. Dura-Ace has always been a study in the pursuit of excellence; this group demonstrates why Shimano continues to dominate the road market.

Final thought: I kinda wish I still raced.


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  1. Fuzz

    I’m sure this group is top notch, relatively speaking, but I was commenting to friends recently that if Steve Jobs ran Shimano, he would likely have already abandoned mechanical Dura-Ace and Ultegra in favor of Di2 and UDi2. Especially with the recent addition of Synchro/Race shifting, going back to a mechanical group would feel like going back to downtube friction shifters.

    1. Author

      That’s a really fascinating supposition. But do we think bikes would have captured Jobs’ interest? If they had, I suspect that Apple would be producing 12-lb. road bikes with electronic shifting, a 14-speed cluster and disc brakes that won’t hurt anyone for $4000.

    2. cycloscott

      @Padraig You forgot the Apple-tax. That Steve Jobs bike would have come in only 1 color, required either 690c or 710c rims and tires that were only available from Apple, and cost $10K. And no upgrades would be available since all components are welded to the frame.

    3. chup

      Nah, Apple is good at software and ecology. Apple will make a bike compatible with iTunes only, create a barrier of entry by enforcing proprietary protocol and connectors for accessories and components. And you know how the product launch press event would look like…

  2. Les.B.

    Don’t suppose you know, but I wonder if the 9100 calipers would play well with my existing 9000 shifters.

    Regarding what Mr. Jobs might do if he ran Shimano:

    I recently read about a company named Salsbury that was responsible for the vehicle known as the “motor scooter”. This was back in the 30s, and what I found remarkable is that the motor scooter had a continuously variable transmission.

    I’m thinking Jobs might have had a version of that transmission designed for bikes. Manufactured with state-of-the art processes and materials, and controlled by an electronic processor.

    1. John Wu

      anyone find significant improvement on braking with 9100 calipers comparing to the 9000 calipers? Knowing the fact that many may change new cables with it thus blurs out whether there’s really an improvement or not.

  3. Winky

    What is “direct” about the new rear derailleur mount? It has an extra link. It should be called “indirect mount”.

    1. Author

      Yeah, can’t help you there. I’m not always clear on how they arrive at some of their terminology. What I can say is that the shifting is ridiculously smooth and light.

  4. Andrew

    That extra link should ideally be built into a ‘direct mount’ mech hanger. At least an option on many mountain bikes where this has been a standard for quite a few years. Then it makes more sense. You can see how beefy that hanger would be. It’s just that not many road bike manufacturers are currently offering this option. In time they will catch up, although none of the other groupset manufacturers have yet to adopt the new standard.

  5. Timbo

    Considering that Shimano still made downtube shifters as part of the 7900 group, I bet they’ll keep producing rim brake calipers for a few more generations. Hopefully.

    Also in the hope category, I can’t wait for the front derailleur cable tension adjuster to trickle down and out to everywhere. In-line adjusters are hideous looking!

  6. Scott G.

    Apple bikes would use superior standards,
    Whitworth threaded fasteners, 597 wheels and
    Swiss threaded bottom brackets.

    Timbo, the 7900 d/t left shifter had automatic cable tension adjust.
    Almost as good as a Suntour power ratchet.

  7. Quentin

    The adjuster on a front derailleur is long overdue. I don’t have anything fancier than 105 on my bikes, but I would honestly consider upgrading just the front derailleur for that feature.

  8. Ken Zukin

    The current iteration of Utlegra 6800 shifters don’t have enough reach adjustment for my short fingers. Looks like this new version of Dura Ace does; how long till that feature trickles down the the new Ultegra group…??

    1. Paul Roberts

      Hi there is a fix to increase the reach that I’ve used to great effect on both my Ultegra 6800 and Dura Ace shifters.

      I got this tip from a professional mechanic for a Pro woman’s team where this is a common issue.

      Replace standard Shimano Screw with
      CUP point Hex Socket Screw
      Thread Diameter: M4
      Screw Length: 12mm length

  9. Spider

    Padraig, awesome comment on the brake…best out there…other than the EE. Those EE have 2 downsides: the price and the fact that everything else feels really average after using them!

  10. James

    So the endless debate in my head, as I build a new bike I will ride in most conditions for many years as if I might race again… would you buy 9100 or 6800 Di2?

    It sounds like these brakes with the HED Black Series rims would give me a reason to keep all my wheels…

    1. T. Guy

      I just updated my custom ti bike from DA 7900 to DA 9100 mechanical. It’s a bike I will ride in most conditions for many more years as if I might race again…..

      Not only am I a bit concerned that rim brakes will be passe in five years, but much more that completely wireless drivetrains and hydraulic brakes will become the norm and cabled systems will disappear, making my classic custom Spectrum bike and several wheelsets obsolete.

      I am absolutely thrilled with the improved, lighter touch shifting, front and rear, the lighter weight, the power and precise modulation of the brakes. The overall synergy of the complete group on my old frame is an order of magnitude advance over the 7900 (a group which I never considered a “misfire”), and I can see another decade of my life on this bike, making the cost/benefit ratio pretty attractive.

      But if my bike were ported for Di2, or if I bought a new frame today I’m not sure I wouldn’t choose Ultegra 6870 Di2 over Dura Ace just because I will want to replace that once the impending wireless future arrives. Luckily for me, it’s a decision I don’t have to make anytime soon.

      Until N+1.

    2. Bryin

      Di2 does ONE thing better than mechanical groups, front shifting… I would say that Di2 front shifting is about 5% better than mechanical DA. This comes at a high cost, not so much in price, but in complexity. To me, after riding Di2 and DA 9000 (9100 soon… I hope) it is not a worthwhile trade off…

  11. Bryin

    How to select cycling components…. (the FINAL word….)

    1. Buy a Shimano Dura Ace groupset… if you need to economize subsititue an Ultegra or 105 part, in this order chain, cassette, brakes). You can buy an Ultegra or 105 groupset and it will work great but if you are bike nut there is no substitute for DA.

    2. Ride this groupset until it wears out or breaks, unless you do something stupid this will take at least 40,000 miles and could be as much as 100,000 miles.

    3. Unless you are a mega mile junkie then by the time your DA group breaks or wears out Shimano will have made a new DA group that works better than your old DA group, repeat step 1.

    4. If anyone tells you that you should try Sram or (God help you) Campy try not to laugh in their face and politely tell them “no thanks”, if they question you further as to why you wont try Sram or Campy simply write the individual off as “too stupid” and move on…

    you now know everything you need to about buying a road bike group set.

  12. Kyle

    Bit of a bringing this post back from the dead, but “how much” better are the brakes than 9000 or even a 6800 series brake? I know it’s hard to put a % on it, but do they justify the upgrade?

    I’ve looked at the EE to replace my 6810 rear chainstay mount brakes but couldn’t justify the price/performance curve. 9100 are 50% the cost of EE’s, and sounds like they are “better”. Anything to assist my 85 kg from not hitting the deck or a car is good. 🙂

    1. Author

      If we are going to compare the Dura-Ace 9100 to Ultra 6800 to the EE brakes, the EE brakes win in every way except cost. If you’re thinking of a brake upgrade to improve upon your 6800 brakes, which are pretty good, the 9000 brakes would be the most cost effective way to improve them. That said, the 9100 are a noticeable improvement over the 9000; not huge, but enough to discern the difference. The difference between the 6800 brakes on the 9100 will surprise you on a descent.

    2. Kyle

      Thanks Padraig! Very helpful.

      Craig undersells his EE brakes – when I spoke to him last year he said “as good or better”. I just didn’t bite because of price and the value of CDN dollar vs. US. Plus duty, and taxes. You get the drift.

      The 9000 to 9100 are about 30$ difference, so I’d probably take the leap to 9100. The extra modulation without insta wheel lock would sure be nice vs the 6800. But I recognize the 6800 are no slouches either


  13. Matt

    Solid review! I’ve been riding my KTM with 5800 on it for just over two years. I consider myself a serious rider, I usually ride hills and average 1500-2500ft climb rides in the 35-50mile per ride range a few times a week. I don’t race. But I bust my ass on my rides and have wanted this upgrade, even tho the 105 has been excellent for me. I think getting this upgrade will make me love the sport even more and improve my braking temendously (these neighborhood hill descents terrify me tbh), and the 105 hoods without gloves are borderline uncomfortable. Just need the justification for this pricey upgrade!

  14. ernie

    Looks like rear derailleur is installed wrong. Might even shift even better if installed correct. My 9100 is the best shifting I’ve ever experienced. di2 ultegra or any other mechanical dura ace.

  15. Rick

    Not sure if mentioned in the comments above, and I’m no expert, but it appears to me that the rear derailleur is not installed correctly. The mounting linkage should be much more horizontal. You might want to check to see if the stop tab on the derailleur is in the correct position relative to the rear dropout/hanger stop. It looks like the mounting link should be rotated about 20-30 degrees clockwise.

    1. Author

      You’re right. I shot the images before I’d really fully adjusted everything. I got the group without any supporting documentation from Shimano, so I made a mistake initially with the linkage. It became apparent super quickly when I realized the rear wheel was impossible to remove. It’s nice to have the Shadow-type derailleur make its way to road stuff; don’t have to be nearly as careful about not bumping the drive side of the bike into stuff.

  16. Pingback: Be-All, End-All? Dura-Ace Di2 Disc | RKP

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