IS ONE SHIFTER, CHAINRING AND DERAILLEUR ENOUGH FOR ROAD BIKES?

As Monty Python’s Flying Circus, the 1970’s British comedy troupe famously said… “And now for something completely different.”  Different, at least, for road cycling enthusiasts, the kind of cyclist I am and write for in these In The Know Cycling reviews.

The completely different things I’m writing about in this post is the SRAM Force 1 and Rival 1 groupsets for road bikes which both use only one shifter, one crankset ring and a single, rear derailleur.  These 1X or “one by” sets had previously only been offered by SRAM for Cyclocross and MTB riders.

While SRAM states a lot of potential benefits for roadies of the 1X – eliminate shifts, no dropped chains, simpler to operate – these are not issues that most enthusiasts worry about that I’m aware of.  Recreational riders, weekend warriors, commuters?  Maybe.  But roadies?

Since SRAM and their Zipp and Quarq divisions have been innovators and changed some of the conventional thinking in our admittedly conservative part of the cycling world over the years, I wanted to evaluate the 1X and see if there was something in it for my fellow road cycling enthusiasts.

By the way, this post is also completely different, at least for me and this site.  I always review and compare products with similar design, performance and cost characteristics in the same post and have never reviewed just one product in its own post.  I do it this way, even though most cycling gear reviews don’t, because this is the way I and most enthusiasts shop for gear.  So maybe In The Know Cycling is also completely different.  (My wife has certainly told me that I am.)

In a sense, however, this review will still be a comparison.  An early mentor of mine used to tell me, life is all relative.  Or, as he jokingly said to make his point, “When someone asks me how my wife is, I answer ‘Compared to whose?’” (RIP DD)

We all have experience with “2X” groupsets from SRAM, Shimano and Campagnolo that have two shifters, two chain rings and front and rear derailleurs.  I wrote a post comparing those a while back (here) and will update it soon with some of the new models that have or are coming out from those three as well as new ones from Rotor and FSA.

So how well does the SRAM Force 1 (best prices, in stock at top rated stores Competitive Cyclist, Wiggle, Chain Reaction Cycles, JensonUSA, Merlin,) and Rival 1 (Competitive Cyclist, Wiggle, Chain Reaction Cycles, JensonUSA) work for cycling enthusiasts?

Derailleur and Chainring

Rear Derailleur, 11-36 cassette, 44 tooth chainring

Fortunately, I was able to ride the SRAM Rival 1 groupset with a Force 1 crankset over a two month period on my road disc bike.  To immerse myself in the SRAM 1X, I rode this set-up 3-5 days a week during this time but also rode and tested out other gear on my rim brake bike equipped with a conventional 2X, in my case the Shimano Ultegra 6800, the other days I rode.

Initially, I thought it was kind of cool only shifting with my right hand.  It took me just a few rides to re-establish the feel and muscle memory of the SRAM Rival 1’s Double Tap shifting system.  With the Double Tap, also used on SRAM’s other mechanical road groups, you tap or push in the shifter paddle with your finger a little to get the derailleur to move the chain down the cassette to a harder gear.  This is the ‘single’ tap.  When you push it in still further, during the same tap, the chain goes up the cassette to an easier gear.  You don’t tap once or twice.  Instead, you essentially double the distance of the tap you would make if you wanted the harder gear to get to the derailleur to move the chain up the cassette for an easier one.

So yes, it seemed having one shifter that you only needed to tap a little or a little more to get all your shifting done across your entire range of gears indeed made the 1X simpler.  But, because the amount of force you need to use to move the shifter paddle to get to a harder and easier gear varies depending on how much tension you have in the chain, it turns out the shifting wasn’t so simple after all.  Actually, I found myself making mis-shifts at exactly the wrong times.

Here’s what I mean.  Riding fast on the flats, say at 200 watts, required a certain amount of tap force to get the derailleur to shift down or up the cassette, to make the riding harder or easier respectively.  But, riding uphill at a 300 watts tensioned the chain more than on the flats and required more force on the paddle to get the derailleur to shift both ways.

Going uphill, if I didn’t tap in the shifter paddle far enough to make up for the added tension in the chain, I would end up moving the chain to a smaller/harder cog exactly when I wanted a larger/easier one to keep my cadence up.  On the flats however, if I tapped too hard or too far, I’d go to a bigger/easier cog when I wanted a smaller/harder one to go faster.

This is really about the Double Tap system more than the 1X but having only one shifter didn’t make shifting any simpler, a benefit I had read I’d get with a 1X.  Because of the greater gaps between rear cogs in the cassette that I’ll detail below, getting the shift wrong because of the cassette you use uniquely with the 1X made these shifting mistakes worse than if I made them on a Double Tap with a 2X Red, Force or Rival groupset.

Of course, there’s a similar kind of chain tension difference when I’m riding with a Shimano 2X groupset.  However, I know that if I tap the right shifter paddle, I’m always going to get a harder gear at the cogs through the rear derailleur and if I push the right brake lever in, I’m going to get an easier one regardless of how much tension is in the chain.  I still do have to push it more or less depending on the tension, but I push it until it clicks in and don’t have to worry about the chain going down the cassette when I want it to go up and vice versa.

And yes, I have to use the reverse logic to move the front derailleur on a Shimano 2X but I do that maybe 1 time for every 25 shifts I make with the rear.  That’s less often that I have the chance of screwing up and I’ve got that reverse logic pretty well wired at this point.

Cassette and chainline

Very clean chainline

After a few rides, I got the shifting pretty well sorted out and stopped making mis-shifts.  While I still prefer Shimano’s separate paddle and brake lever actions for shifting for the reasons I’ve just mentioned, I imagine the learning curve for people moving from a SRAM Double Tap to a Shimano two lever system would be much greater than the other way around.

With the derailleur now moving the direction I wanted with the Rival 1, I often found that my cadence changed more dramatically, as much as 5-8 rpm more, after shifting in the 1X than with the 2X.  In addition to messing with my rhythm, this affected my effort to keep my power output going up and down evenly and in a certain training range.  It also caused me to want to shift less to avoid the big cadence and power changes when ideally I should be shifting more frequently to keep my cadence and power steady as the road turned up or down.

What was causing this?  Was this due to having only one front ring?  Why?  How?

I selected a gear ratio on the 1X (44 tooth front ring and 11-36 rear cassette) that would give me essentially the same range and top and bottom end ratios of my 2X (50/34, 11-28).  I knew there were different gaps as you stepped up and down the cogs in the two cassettes, but I tried not to think about that during the time I was riding the 1X.  I didn’t actually detail them until I began to write this post.  I wanted to feel the difference riding between the 1X and 2X rather than think about it and being biased by that knowledge.  Certainly, I had a hunch about what was going on but tried to keep a potential explanation in the background so I could better describe what I was feeling in my legs and seeing on the bike computer.

I normally ride in my larger 50 tooth ring on my 2X unless I’m going up a steep or long climb.  The 25 and 28 cogs in the back give me enough to get over most hills with a cadence still in the 70s.  (I’m light, not strong).  If the pitch is going to be steeper than 5% or a long climb near or just below that pitch, I’ll switch into my 34 ring to keep that cadence up and avoid tiring.  On the steepest climbs with the 2X I’d be using a 34 tooth ring with a 28 tooth cog for a ratio of 1.21 and on the 1X, a 44 ring and 36 cog for a 1.22.  No diff.  I’d be working just as hard either way.

At the other end, if I was pedaling full-out going downhill or sprinting full-gas on the flats, I’ll be at 50-11 or a 4.54 on the 2X and at 44-11 or 4.0 on the 1X.  Sadly, I don’t often find myself in those situations so this difference was something I never really noticed.

With the 1X you can get more range by using a different cassette and ring.  If, for example, you are climbing really steep mountain pitches and want more range on that end, you can go with a 10-42 in the back.  If you want to avoid spinning out going downhill, you can go with something like a 46 or 48 tooth ring in the front.  Using a 46 and 10-42 will get you a 1.1 ratio going uphill and 4.6 on the downhill or flats, a wider range than the 11-28 2X set-up.

To match this with the 2X however, you can go with an 11-32 with the same compact 50-34 up front to get you 1.06 going up and the same 4.54 going down.

So the same range and top and low-end ratios can be achieved with the 1X and 2X.

What is different, of course, are the steps you take between the cogs in each cassette across those similar ranges.

Let’s go back to the set-ups I rode in my comparisons, an 11-36 with the 1X and an 11-28 with the 2X.  Of course, both have 11 cogs because they are 11-speed cassettes.  While they both start with an 11-tooth cog at the small end, because you end up with cogs having different teeth at big end you have shifts where the number of teeth or “gaps” between adjoining cogs or gaps is different.

Here are the number of teeth in each cog of the cassette:

  • 11-36: 11-12-13-15-17-19-22-25-28-32-36
  • 11-28: 11-12-13-14-15-17-19-21-23-25-28

What you see here explains why my cadence and power was varying so much between shifts on the 1X vs. the 2X.  With the 11-28 you get 1-tooth gaps for first four shifts, 2-tooth gaps for the next five and a 3-tooth gap only for the last shift between the 25 and 28 tooth cogs.

With the 11-36 however, you only get two 1-tooth gaps shifts and three 2-tooth gaps.  When you get to the middle of the cassette, you start shifting through 3-tooth and 4-tooth gaps.  As I ride most of the time in the middle and upper range of my cassette, the gaps between shifts with the 11-36 turned out to be 1.5 to 2X what I normally experienced with the 11-28.

As a roadie trying to ride a steady pace whether going on the flats or up and down the hills, I noticed these differences.  You would think you shifted twice with the 1X when you hadn’t.  Heck many roadies bemoan not having a “16” in the middle of the cassette and forego the safety of have a 28, preferring to ride an 11-25 just to pick up that 16.

IMG_2770

I can imagine riding a CX or MTB course where the pitch and pace is constantly changing, often in greater amounts than what we roadies see on the pavement.  As a CX or MTB rider, you’d probably welcome the 11-36’s or 10-42’s bigger gaps as it might take you two shifts on an 11-28 to get the new gear ratio you want and you can get there in one with an 11-36 or 10-42.

Shimano has introduced their own 1X groupset recently as part of a play for commuter bikes.  While commuters ride the same road terrain that by many enthusiasts do, they may have more reason to shift up and down in big steps however, to match the traffic speed changes on the road.  Having only one shifter, ring and derailleur is probably less maintenance, a bigger issue for commuters, CX and MTB riders.

In the end though, the 1X may be a bridge too far, or have gaps too big, for road cycling enthusiasts.

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17 comments

  • I would echo your reservations on Double Tap. Certainly if Di2 is the benchmark, it can feel a bit clunky and imprecise. However despite this, I can see the clear merits of 1x. Even the most advanced front derailleurs at their core are a pretty crude piece of engineering, and in my experience a source of more hassle than rear mechs, so if I can live without I’m happy. Plus I do think roadies care about chain drop, at least round my way where the roads can be rough. The clutch rear mech on 1x, which keeps the chain under tension all the time, is a massive benefit in this regard. I am using 1x (50T front, 11-32 rear) on one of my bikes and if a good electronic shift version came along I’d be tempted to do move to 1x on other bikes. You mentioned commuters, but I can also see the merit of 1x for other road applications such as TT, where less gearing range is required. Hopefully Shimano and Campag enter the fray on this, and we end up with more choice of good quality 1x drivetrains.

  • hi steve. thanks for your comments. i’ve wondered what a 1x for road bikes would do to pedaling cadence and power gaps and imagined it wouldn’t work for me, and for exactly the reasons you’ve witnessed here. i’ll wait until i’m older and lazier and looking for fewer hills to climb and slower speeds to sustain.

  • I converted my Bianchi Infinito CV from Campag Churus 50/34 11-29 to Sram Force1 38T with Shimano Cassette 11-32 (plus another spare 11-42 for high mountain climb), and I completely happy with this.. Here is the readon why..

    For 1x, you have to know what kind of riding you plan to do with your 1x bike. I set up this Bianchi + 1x (+ Dura-ace c35 wheel) for cycling trip, endurance riding, hilly terrain or high mountain climbing, and 1x perfectly fit with my expectation, and much better than any 2x system.. Why

    – It’s simpler and easier to maintain when I was out for the trip. No FD problem. No drop chain. No noise. Much more easier to remove or install the rear wheel due to SRAM’s cage log system. It’s really peace of mind factor.. My riding happiness increases..

    – For hilly terrian (up and down road), for 2x, you have to often change BOTH front chainring (left shifter) and rear casette (right shifter) if you ride in up-down-up-down road, and many times I have to “look down” on my cassette to know what rear cog it is, in order to adjust shifting properly.. But for 1x, you only have one thing to click, your right shifter.. It’s much much simplier and much more effective.. No need to think left or right or no need to look down what rear cog I use any more.. Free up my brain.. More focus on the road.. My riding happiness increases..

    – For 1x 38T + 11-32 set up, it’s can go as fast as 45-50kmh on max speed, which I think it’s more than sufficient for the purpose of this bike (it’s not for racing purpose), plus give me the safety speed limitation.. Ultegra’s 11-32 cog give me relatively smooth cadence from speed 27kmh up.. For climbing, 38-32 gear ratio is similar to normal gear ratio of 2x’s 34-28, so I don’t lose anything here.. BUT the key benefit for 1x is on high or long mountain climbing.. Whenever I want, I would replace my 11-32 (Shimano Ultegra) cassette to 11-42 (Shimano XT), and now I’ve got 38T 11-42 (I use long cage RD, which can accommodate 42 cassette).. With 38-42 ratio, I can safely say I can enjoy climbing 20%+grade steep mountain without hurting my knee or lower back.. My riding happiness increases..

    – Lastly and subjectively, I think the 1x makes my bike more beautiful, more clean, and more elegant look than 2x, especially when removing that ugly FD out.. Here, my happiness increases again..

    As mention, for 1x, you have to know what kind of riding you plan for your bike.. And once you know, and you choose the right combination of front chainring (38T up to 55T) and cassette (11-23 up to 11-42 or 10-42), you will be rewarded with much more happiness riding experience 1x can offer.

    Note: I also have another bike, S-works Tarmac with 52/36 11-28 and use this bike mainly for racing on mostly flat road.. The rest of riding, I use Bianchi Infinito CV + Force1.. But if I can only have 1 bike in my garage, I still choose 1x over 2x from the reason above.. Thanks

    • hi kent: nice reply to the 1x question. i’m still holding off since my 2nd bike is still working ok for me. it’s a triple which i really HATE but it’s a good bike and i’m not ready to replace it just yet. my other bike is a road bike and i’m not convinced the 1x set-up will work for me on the road bike. nice comments though!

  • Interesting comments on double-tap. I have mechanical Shimano and SRAM equipped machines and prefer the latter. I’ve never missed a shift climbing or sprinting and never thrown a chain (Force 20 & 22). Can’t say the same for either the 105 9sp standard or the Ultegra 10sp standard equipped rides where all of the above has happened.

    The primary argument for my switch came from a mechanic at my LBS – the SRAM mech components are cheaper and easier to work on (plus, in his opinion, the company was easier to deal with). It took a couple of rides to get the hang of it – front der was the most challenging but now it is second nature.

    • Kevin, As I wrote, I re-established my SRAM muscle memory after a few rides and I’d expect the learning curve with SRAM would be quicker than with Shimano for most. I found the gaps between shifts to be too big with the 1X that matches the range of the 2X and suspect I’d be for most road cycling enthusiasts. I’d tend agree with your mechanic that SRAM is probably easier to deal with but most of their 11 speed gear is more expensive than Shimano’s. As to how easy or hard they are to service relative to Shimano’s, I think it’s more a preference for one or the other, much like their shifting systems. Steve

  • Excellent article Steve, glad to read unbiased reviews.
    What do you think about cross-chain? I was always told to avoid big-big and small-small chain-rings to avoid wear in my drive-train.

    • Ops! I forgot the point of my post. Can cross-chain be an issue in 1X systems?

      • Juan, with only one ring, there isn’t a cross-chain situation to consider. I found the 1X chain line to be clean whether in the smallest or largest of the rear cogs. I also believe current SRAM and Shimano 11-spd groupsets don’t experience the kind of rubbing that would induce wear that we used to experience with cross-chaining in 10 or 9 speed groupsets. The front mechs have gotten better. That said, I don’t like cross chaining as I think the chain angles likely produce a less efficient power transfer than the smaller angles you’d get with the same ratios using the other chain ring and the right cog. I also don’t have a good/smooth next shift available to me when I’m cross chained. Steve

  • “Heck many roadies bemoan not having a “16” in the middle of the cassette and forego the safety of have a 28, preferring to ride an 11-25 just to pick up that 16”

    Then why not just grabbing a SRAM 11 speed 11-28 cassette which is 11-12-13-14-15-16-17-19-22-25-28 instead?
    it has both 28 and 16.

    • Hxs, Yes, that’s an option too if you do most of your shifting in the middle of your cassette. The trade-off is the 3 step jumps at the higher end. I’d love to see Shimano and SRAM do a 12-28 so you could get the 16 and smaller gaps at the top Hard to make everyone happy 🙂 Steve

      • right,
        12-28 should fit most people better. Shame that it’s only offered in Dura-ace not Ultegra/105 and none at all from SRAM. Where many people who need Dura-ace Cassette (people who need the last bit of weight saving even on wear-down component like a cassette.) may have a use for 11t cog. It sound like a plan to force sell Dura-ace cassette to me. (Although i can also buy Ultegra 12-25 and 11-28 then mix them together for cheaper than single Dura-ace cassette alone.

        • @Hxs : I’re right. Mixing two Ultegra cassettes, 11-28 and 12-25, give us the missing 12-28 for half the DA 12-28 price. It is an easy job to do, you’ll have to use the 17B (the 17 that came from the 11-28) and the shifting is perfect.
          From the 12-25 keep : 12-13-14-15-16
          From the 11-28 add : 17-19-21-23-25-28
          I rode this in Provence and it is the perfect balance with a compact chainring (50/34) between the 12-25 & 11-28 IHMO.

  • Dear Steve,
    first I would like to thank you a lot for your web site, which is very interesting.
    I have spent a lot of time reading your articles. I like your point of view and I have followed some of your advices. For example, after buying a pair of C24 wheels, I recently bought a pair of C35, which I enjoy a lot.
    Two months ago I start to study the possibility to modify my bike to have a single chainring. My current bike is equipped with a 36-50 and a 10 speeds 12-25 or 12-27. Most of my rides are 70-100km long with typically 700-1000m of elevation. Thus, after studying my rides and developed a software to infer the time spent on each development, I came to the conclusion that a 44 chainring would be optimal with a 11-36 cassette (or a 11-32). Then I discovered your article. And fortunately, this is exactly the setting you have experimented. After reading your article, I was a bit disappointed, mainly because you pointed out the annoyance of the gaps in the cassette. This cannot be easily modelled in a theoretical study.
    So, instead of completely modifying my bike, I started to replace my 36-50 chainrings by a single 44 chainring, using my actual ultegra rear derailleur and my current 12-27 cassette. The experiment was very positive. The chainline was perfect, with no noise anymore. The 12-27 was bit too small for climbing and a bit too long to reach 55km/h. So, I installed a roadlink (from Wolf Tooth) and replaced my cassette by a 10 speeds 11-32 (11-12-14-16-18-20-22-25-28-32).
    I am using this setting since 700km and I am quite happy. The gaps in the cassette are not so annoying except may be the gap between the 22 and the 25 when you have to climb a 4-5% road.
    I am doing some of my rides in a sportive group where I cannot choose the speed (the speed is imposed 🙂 and this is not so bad, I can follow them.
    I am using 44 / 11-32 because I need the 44-11 to follow the group I am riding with, but I have discussed with someone who tested this setting on a longer period, and he recommended me to use a 42 with a 11-28 cassette to reduce the gaps. This may be a good solution for someone who does not need the 44-11 (equivalent to 52-13). 42-11 may be sufficient in many cases.

    So, my conclusion would be a bit more positive than yours. I am using 10s and I am quite happy. With 11 speeds it should be even more confortable, and I am convinced that single chainring may become mainstream with 12 speeds cassettes.

    cheers

  • Good discussion this one. I’ve been riding with force CX1 (on a road bike) for 2 years now and have no intentions of going back to 2x.

    Practically all of my riding is in hilly terrain, and when using my previous setup of a shimano compact groupset, my repeating annoyance was the loss of climbing momentum when switching between big ring and small ring to avoid cross chaining.

    I don’t notice the slightly larger gaps in ratios as you mentioned. They occur in the lower climbing ratios where cadence is not as critical and can be adjusted too without loss of ‘performance’.

    I also think that a person’s riding adapts to the bike.

    The force 1 cogs have different sized teeth (wide tooth narrow tooth) which reduces a lot of drag and chain lateral twist associated with cross chaining. It makes for the occasional noisier shift but the operation is still smooth and consistent.

  • Great web site and reviews – so glad I found it! 🙂

    I agree with the above comments that:
    1. 1x is much more likely to become accepted into road riding when 12spd cassettes become standard.
    2. For CX and Gravel, the 1X may make more sense. CX typically is a much narrower range (ex. 36/48 chainrings) and standard racing cassettes – and many CX racers already are using 1x systems. When gravel riding I often find myself double shifting my 10spd 11-26 cassette so an 11spd 11-32 probably would be a very effective set of gearing… But 12spd would give good range and reasonably close gears (10-32?). Yeah, I could see myself picking up a new bike with 1x 12spd.

    That said I disagree with criticisms of 2x systems being inefficient, unreliable and/or complicated. All my 2x bikes are setup 50/34 or 52/36 with 10spd in back. I live in Colorado along the front range of the Rockies – long climbs, rollers and wind. I need low gears for getting up 1+ mile climbs of 10% grade, and a tall enough gear to keep up on descents at 45++ MPH. Oh, and closely spaced gears are a huge help when riding with groups of racers.

    IMHO 2x shifting isn’t that complicated – I’ll pick the chainring to put the chain in the middle of the cassette and then adjust for small changes in conditions/pace with the rear derailleur. Sudden large changes frequently require a shift of the front. To maintain momentum power and speed when going into a hill, I’ll upshift the rear in preparation to down shifting the front. Most of my bikes have Campy which is easy for me to dial in the front derailleur, but for me Campy is more fickle with rear adjustment. My race bike has SRAM red that is much more fickle in front but rock solid in back. My wife only rides Shimano – we’re a family divided. YMMV but my point is that the 2x stuff works. Agreed, 2x is not as simple as 1x but a well setup 2x is reliable and effective.

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