First published November 4, 2017
With more and more sprockets on our wheels, do we still need two chainrings up front? We take a deep dive into the pros and cons of 1X gearing.
The drivetrain on a modern road bike has evolved loads since the early days when you turned a lever to move the chain to a different sprocket. Electronics are now commonplace and cassettes with ever-wider ranges provide enough gears to tackle even the steepest mountain climbs.
Most modern road bikes use two derailleurs to move the chain across the cassette and chainset, and it works well thanks to many years of product development. We probably take them for granted. But there's a move in some parts of the cycling world to simplify the drivetrain and it threatens the future existence of the front derailleur.
The arrival of SRAM’s 1x11 drivetrain a few years ago, a gear system that ditched the front mech and instead combined a single chainring with a wide-range cassette, provided another path. Such drivetrains have become hugely popular on mountain bikes and we've seen cyclocross and gravel bikes also being specced with single chainsets in recent years. Could the same happen to road bikes?
What are the benefits of 1X gearing?
The simplicity is certainly appealing. With just one shifter, changing gear is much more intuitive than having to manage the front and rear derailleurs. For beginners, that's an obvious benefit. There’s one less component to fail as well (though front derailleur failures are rare) and on bikes designed for wider tyres, removing the front derailleur can provide additional clearance around the rear wheel and seat tube area.
Read more: Beginner's guide: understanding gears
A short history of the front derailleur
Early users of double chainsets didn't even bother with front derailleurs; they pushed the chain from the large to small chainring with their heels at the bottom of a long climb, then stopped at the top of the hill to manually lift it back to the big ring. In the 1930s, French cycle tourists began using mechanisms to move the chain, as they realised being able to change gears was useful on the flat as well as when you had a long climb ahead.
Front derailleurs of the 1930s were usually actuated by cables; rod-operated front derailleurs appeared in the 1940s, and provided very quick and efficient shifts. You had to reach down towards the bottom bracket to operate them, which looks awkward to modern riders who are used to brake/shift levers, but was reportedly quite straightforward.
Read more: First Ride: SRAM 1x Road
Since then, the front derailleur really hasn't changed much at all. It's still a basic component, comprising two metal plates that shove the chain across the chainrings, and the stiffer those plates the better the shifting. But making plates stiffer by making them thicker also adds weight, so gear makers have added ramps and pins to the chainrings, bringing a real improvement in front shifting performance. The biggest recent development has been the addition of a motor in the electronic systems made by Shimano, Campagnolo, SRAM and FSA.
The 1x charge – the industry speaks
But the cycle industry is in a great period of technological development at the moment and everything is up for change. Chainsets have evolved from triples to doubles over the years with loads of configurations available, but a definite trend towards lower ratio setups like a compact, semi-compact and most recently, sub-compact. So if lower gears are popular, why not go all the way and use a smaller single ring?
For mountain biking, a single ring chainset makes a lot of sense. Changing gears is easier with just one gear shifter, there's one less thing to malfunction, mud and ground clearance is improved, weight is lowered and suspension designers are freed from the limitations of having to factor in a front derailleur when locating pivots. And any loss in gear range is compensated for by a wide-range cassette, with SRAM’s introduction of a 10-42t cassette and more recently 10-50t with its 12-speed Eagle groupset.
SRAM has been instrumental in the popularity of single ring drivetrains, but SRAM’s Global Drivetrain Category Manager Ron Ritzler doesn’t think fans of the front derailleur need to worry just yet.
"Will the front derailleur disappear? Probably not yet as there are certain users, like some elite athletes, who need the range and the steps to perform at their best – but can it kill the front derailleur for users who spend their time in cyclocross, commuting, adventure riding and in events where fast precise single ring performance is preferred; heck yes,” he tells us.
“We still make front derailleur and 2x rings that work really perfectly, but we love the fact that there are some many people using road bikes in new ways that make 1x the right choice."
While SRAM has been cheerleading the benefits of single ring drivetrains, Shimano isn’t really embracing it. Shimano’s Ben Hillsdon says the versatility of the double ring setup is just too good to ignore.
“Essentially the front derailleur doubles the number of gear ratios available to a rider, and, therefore, gives riders smaller steps in shifting between their biggest gear and their lowest gear,” he says. “That means riders have a wider range of gears, a smoother pedalling experience and their cadence (ie leg speed) can stay constant.
“That, in turn, brings a physiological benefit as muscles and joints are saved from being overworked, which can be crucial when it comes down to the sharp end of a race. The versatility of a double-ring setup is that you can go anywhere without compromise. However, for those riders choosing simplicity, our strategy is to offer drivetrains that can be set up in many different ways for different styles of riding.”
Read more: Your complete guide to SRAM road bike groupsets
Since we spoke to Ben Hillsdon, Shimano has backtracked a little though, introducing 1X options in the GRX range of gravel bike components. Okay, a gravel bike isn't a road bike, but there's no reason you couldn't use a gravel bike transmission on a road bike as long as you can get a top gear high enough for mountain descents and sprint finishes.
In fact, that's exactly what 3T have done with their Strada road bike, which now comes in a version with Campagnolo's 1X13 Ekar components. Ekar is intended for gravel bikes, but 3T clearly don't believe in discipline boundaries, and who's to say they're wrong?
But a front derailleur gives you more gears, right?
One of the biggest advantages of the front derailleur was a big increase in the range of gears. That was an obvious advantage with a 5-speed cassette many decades ago. Over the years, the number of sprockets on the cassette has increased and is now up to 11, 12 or even 13.
Not only has the sprocket number increased, but the size of the sprockets has gone up: most racers predominantly used 12-23 cassettes a few years ago, but 11-30 is now common in the pro peloton and many sportive bikes now come with 11-34 cassettes.
Of course, removing one of the chainrings reduces your available range so to combat this SRAM introduced a whopping 10-42 cassette. It was instrumental in winning over mountain bikers as it was possible for a single ring drivetrain to offer nearly the same gear range as a conventional compact drivetrain.
Read more: SRAM Rival 1 review
How does a single ring drivetrain compare to a conventional drivetrain? Favourably, if you look at the numbers. Combine a 44-tooth single chainring with an 11-36 cassette and you have a gear range from 33 to 108 inches. That’s very nearly the same as the 32.8 to 122.7 range that a 50/34 and 11-28 setup provides, a setup many riders still use, though the latest off-the-peg bikes tend to have an 11-32 or 11-34 cassette.
You can adjust the size of the chainring and the cassette to tailor that gear range to suit the geography of your local terrain and riding style, whether solo touring rides or racing, much like you modify a current drivetrain with different chainsets and cassettes depending on whether you want top-end for racing or low-end for riding in the mountains.
While the gear range compares favourably, where the 1x setup falls short is in the jumps between the gears. This will concern those cyclists who like to be in the perfect gear for the optimum cadence at all times. How big a concern the larger jumps between gears will be to you depends largely on the type of cyclist you are, the sort of riding you do and your terrain. There is much work being done to provide cassettes that can help smooth the transition in the most frequently used gears, with 3T's Gerard Vroomen developing two versions of a 9-32t cassette that looks to be a good choice.
So should you ditch the front derailleur?
That depends. There are clear advantages and disadvantages to a 1X drivetrain at present. It’s unlikely we’ll see the front derailleur confined to the history books anytime soon, especially given Shimano’s dominant position in the market. That'll certainly be the case for regular road bikes and especially race bikes where tradition rules.
Where we're seeing single ring drivetrains really start to become a lot more popular is on bikes where the disadvantages are outweighed by the advantages offered by a simplified drivetrain, where the ultimate range isn't as critical and where the bigger jumps aren't as much of an issue.
Read more: Will your next bike be a gravel bike?
We’re talking about cyclocross bikes (where many racers have been going single ring for many years already with home-brewed solutions) and the gravel and adventure bike category where 1X is as common a transmission option as 2X. But with the likes of the 3T Strada and Whyte Wessex One, two road bikes designed around 1x11 drivetrains, we could be looking at more road bikes devoid of front derailleurs in the future.
Ultimately, though, the modern double-chainring transmission is too good for many cyclists to want to make a radical change. But the rise of wide-range cassettes does provide an interesting alternative that will appeal to many cyclists, which means we might see a few less front derailleurs on road bikes in the future.
Do you ride a bike with a single ring drivetrain?
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125 comments
What puzzles me is the cry that a front mech is a weak point. Unreliable maybe? Marketing and thats all in that respect. Cobblers. Its the simplest, most fool proof moving part on a bike and its being replaced by a complex clutch mech that dangles close to the ground. Weight. I fail to see that the guts of a changer plus a cable and mech add up to the over long rear mech plus all those sprockets . Complexity? Really ? Whats complex? its automatic.
And there we come to it. If you don't know any better then you don't know the whole story. If all you know is a single ring then you don't know whats wrong A single ring suits the new MTBers who can't pedal properly .
A single is ok for flat TTs and real CX ( not messing about off road)
Marketing and nowt else.
Funny thing was when I was a youth the traditionalist mocked me for having a ten speed - wasn't I up to a five speed, did I go for every gimmick? Now the traditonalists say eleven is insufficent. Cycles may have changed a lot, but cyclists have changed even more.
In the year since the article we still don't have 1*12 speed road, but we can see it is at proto stage, and there's the 13 speed Rotor too. Looks like a decent solution, but they may never make the mass market.
Personally, if I'm going to have a front mech, I've probably enjoyed *3 most, because 90 percent of the time I can just leave it in the middle. Sure the granny gear is clunky, but rarely used so who cares.
On roads, many casual riders with front mechs have not the slightest idea how to choose the right gear - constantly stuck in a 36 inch or 110 inch gear, who knows: gear or brain seized up? Those with single mechs, often with twistshifts, seem to get it about right..
For casual riders, 1x is great: cheaper, conceptually simpler, less bits to break ?
I prefer to ride at the right cadence, so prefer 2x for road and 3x off-road.
Some interesting posts here, but moot for me. I've given up trying to buy an SRAM Rival 1x11 groupset. When I finally got through to someone at SRAM they seemed to be proud of the fact they don't sell groupsets and that it's near impossible to buy their kit.
I've just invested in another triple set up, so 3x11 24/39/50 + 13-30, hello mr 20%.
People ditching the front drailleur are simply making it harder work for themselves whatever the activity IMHO.
IF I decide I want to cart a shedload up a lot of inclines day in, day out, I'd probably opt to fit something like a 34T but even with my lardy arse and aging legs I can still just about manage to do 14% inclines with that gearing with a reasonable load, not for very long mind but low enough gearing to get me over the worst, being able to twiddle away on a 7%-8% without spewing/having to stop/do zig-zags is why a front drailleur and a triple for those environments is essential for me and many others.
1x is dead, long live the FD!
Well I have a single ring shopper bike with 21 gears, it is equipped with the Sram 3x7 ( seven block on 3 speed hub), named shopper as that is it's main use, it will happily go on any terrain with the 28 tyres. Up to now the chain has derailed a couple of times, mainly due to my abuse of the system, no doubt a thick and thin chainring would sort that out but for the short journeys I do on the bike it is not worth the outlay. Ratios I know not, my legs and lungs tell me when to change gear, I live in a lumpy area and the gears are fine. I use a close ratio compact 9 speed on short time trials, local flat course, the small ring being a godsend on a return to HQ with thick legs. I'm not a hero, just an eighty one year old putting some effort in!
It's horses for courses..... For road use, for most 'casual' cyclists, or beginners, a 1x system is the way to go, it is much easier to use. You change one way to 'easier' gears, the other way to 'harder' gears. As has already been pointed out it is amazing though how many 'experienced' cyclists you still hear/see badly cross-chaining so still don't really 'get' how a 2x system works (and don't get me started on how many expensive bikes I see/hear being ridden with rusty, squeaky chains!) but maybe it is just not important to them as long as it works!
However, as a cyclist becomes more experienced, maybe takes part in sportives, maybe joins a club and rides faster paced club runs, maybe goes for local Strava segments, and then maybe even tries their hand at racing, the importance of having the 'right gear' for the particular road, weather and (if applicable) race conditions gradually becomes more and more important and steps between certain gears become more of a problem. That step to someone on a sportive might mean they have to go a bit slower on a particular climb, rather than blow their kneecaps off in a hgher gear but they might actually be glad of that at the time. However, the same step to someone going for a sprint in a race could be the winning margin.
I myself do the bulk of my miles (commuting) on a 1x11 system, well, it is actually Shimano Alfine 11 speed hub gears with Di2 shifting and belt drive but will happily do longer rides on this bike too (it is a drop-bar 'performance' bike rather than a hybrid or similar) and only very rarely have I found myself lacking a gear - usually when I am tired and flagging on a long climb, when small differences in gearing have a bigger physical/mental impact. 99% of the time though, for me riding on my own, commuting or 'leisure' rides (i.e. 16-18mph average) over a variety of terrain (sometimes do big climbs and up to 50 miles on this bike) it is fine.
For longer, weekend rides however, my 'best bike' is 2x11 and although I have a very slightly wider gear range on this bike I often used find on undulating rides I was frequently switching between big and little rings but this is much improved after changing from 53t to 50t for the big ring (I am no racer!).
Personally I think many new-starters are put off by the complexity of front and rear derailleur gears so I think 1x11 could help alot of those people get into cycling more readily and enjoy their rides more, without constantly thinking whether they are in the right gear or not. Those people might then get more interested in the sport and could then relatively easily upgrade to a 2x (or 3x) system when/if their requirements change.
So I think both systems will be around for a long time as there are pro's and con's for each setup, and if you are lucky enough to have more than one bike there are good arguments for owning both systems depending on the type of ride you are going on. Thats what I told my wife anwyay.....
I've never found using a front derailleur problematic at all, even on triples (which I think still have their place, on loaded tourers, at least), and prefer closesly-spaced gears, but wide gear range. Also, although this is probably not a very valid reason, I don't like the look of the (relatively) small chainring and huge dinner plate cassette on a 1x road bike.
So I can't see myself moving to 1x any time soon for road bike riding.
I’ve been predicting and/or hoping for a future that doesn’t feature the front derailleur; I can’t stand moving to the granny ring it feels like a lot of hard work for little gain. Maybe a result of commuting on a fixie but seems to me the same range is very nearly there with one front ring. Shifting the front is no drama but it feels a bit much ado about nothing if you ask me. My prediction is us roadies will get there in the end and we’ll look back and wonder why we ever bothered!
I had the chance to build up a really nice tourer using a steel Raleigh frame a neighbour was throwing out (why some people chuck out good stuff escapes me). It had built-in adjusters. I've some old but still decent road wheels in the cellar and a decent old mech.
The plan was to build a 6 speed for hacking around, old school but nice. I like the idea of a simpler layout with a rear mech only. Fewer cables means less maintenance.
I still kick myself that I never got round to picking up the frame from my neighbour.
I think for non-sporting cyclists, the front mech should deservedly die; I've seen too many casual cyclists struggling in the wrong gear because they don't know what to do with the front cogs.
But I won't ever give it up, I love having close ratios on the rear cogs and, particularly, get a lot of pleasure out of the 'double squeeze', going from small to large at the front and two down at the rear (maybe with a 'blib' for another one at the rear). It's part of what makes cycling feel like an art form.
Ive got 3 front ring in digital form
Hi! I have an adventure road bike whith an 1x transmission: Chainring 40t + 10-42.
In winter my rinding is mainly in tarmac and not very steepy and I'm going to buy another chainring. I don't have to much experience and I would like to ask for advise, I wonder if buying the 44t or 46t, considering I'm going to keep with me the 40t in case I need.
Thank you
I have no intention of going 1x on my good road bike, as I like the close ratios achievable with 2x over long distances.
CX/commuter bike would be ok with 1x11 and have certain advantages, but I'm only riding them for an hour, tops, at a time. I probably only use about 4 gears on my commute anyway and could custom spec a cassette for it.
Can see the advantages of 1x on an MTB, as close ratios aren't such an issue.
However, cross-chaining across 11 gears just can't be a good thing and cost of cassettes puts me right off.
Wheel strength must surely become an issue with the amount of dish required to accomodate 12/13 speed cassettes, unless the dropouts become wider.
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Chainline and efficiency.
With a 2x or 3x setup the chainline can be kept straighter than a 1x system. The efficiency of the drive decreases with chainline offset. A single speed bike has an efficiency of the chain drive of around 99.7% (A Study on the Efficiency of Bicycle Hub Gears, Elizabeth A. Casteel and Mark Archibald, 2013). With a 7 speed (x1) derailleur system that drops to a low of 97.5%. For 11 speed etc. that will come down again - and also drastically increase chain wear as others have said. For me, this 1x set-up doesn't make engineering sense and is more about selling bikes and bits than anything. For a recreational bike and easy useability, hub gears make more sense, are almost as efficient and the chain and sprockets will last much, much longer.
See also "Are caliper brakes dead?" an other such nonsense.
ride what you like, how you like, when you like, where you like, wearing what you like and ignore both the marketing bozos and their "Is nnn dead?" hyperbollix and the Keepers of the Flame and their "Rules".
While I completely agree with your sentiment Workhard, unfortunately as standards change, parts, especially quality parts become increasingly difficult to obtain.
My getting to work/everyday bike is getting retired at the moment, it's taking a little longer than I would like, which I started to think about when Mavic stopped making their wonderful XC 717 26 inch rim brake rims, then Sram stopped making nice 8 speed chains (she's a 3x7, but 8 speed and 7 speed chains are the same) I have been running 8 speed casettes for may years, and not using a cog, mainly the big but my last commute I left the small, and the XT versions are getting very expensive NOS on ebay. Yes I can get stuff but she deserves quality. I've been using her for 22 years, she's a Marin Pine Mountain from 91, best £250 I have ever spent.
My current build, Surly Ogre with Rohloff has so far been with the LBS for 10 months, only recently back from Germany, she's already more travelled than I will ever be, choices I have made, but "standards". I am trying to bribe them with cake to hopefully hurry them on a bit. Going to bake them a caramel cookie traybake this afternoon, and go and see them tomorrow. You never know.
Roadbikes are a little more immune to rapidly changing standards than mountainbikers, but it will come. I'm hoping the Ogre with Rohloff has enough wiggle room to get me 10-15 years with ease, and then maybe a few more until my retirement. Already my choice of 3 inch 27.5 tyres is pretty much defunct, but I can switch to 29s with maybe 2.6s easily enough.
1x11 or 2x11?
Err, 2x please. For me personally, it's a 50/34 and 11/32. It'll get a fat bloke up 20% and down the other side.
I'm quite capable of working a front derailleur and I don't ride through mud. So, um... Why?
Actually a while back i was all about the 1x. But now i race a bit and do some fast stuff in packs on roads, i think maybe not. Cadence is the issue. Until someone does a 15 speed cassette with 1 tooth gaps all the way through the first 8 sprockets, roadies will always hate the big jumps. But for cross and gravel and mtb, yeah, 1x all day. Actually maybe not for gravel, on reflection; i still think i would rather run GRX 2x than 1x, as its a bit like road racing in some ways.
Is this article dead?
no.
I thought consumer demand was supposed to motivate innovation but these days technological development appears to be industry motivated, perhaps for the purposes of standardization and profit. Case in point are disc brakes. Some commentators are saying rim brakes will be phased out in preference to disc brakes. Well I don't want disc brakes. They make the wheels heavier reducing acceleration performance.
Is the front mech dead? No
Is there a future for the front derailleur on modern road bikes? Yes.
Just another re-hashed article brought back. At the CX Euros last weekend some riders were using double chainrings.
Overall, single chainrings are in the substantial minority. A Niche product
Not dead.
The huge cassettes look rubbish on road bikes and the gaps between sprockets are too large - certainly for racing.
I find even with a 13-28 and a 50/36 or a 53/39 that I'm not fully comfortable with the gear I'm in.
People say you only need small jumos for competitive riders but it's just as important when touring or commuting, maintaining your sweet spot almost anywhere on your ride but particularly at the end of a long day is important, if you're tuckered out then a big jump is just awful, fully loaded it could be the difference between maintaining momentum and actually coming off/putting a foot down.
Is that a canyon inflite set up as a 1x roadbike? Brilliant!
A gappy cassette is a right pain. My cross type bike has 46/36 up front and 11-32 ten speed at the back. The cassette has big gaps in the middle. I’d hate to think what it would be like if I were trying to cover 50/11 at one end and 34/28 at the other in just 12 speeds on my main road bike.
What do you operate the lever with? Your tongue?
So having a choice of 2 chainrings is too complicated for newbies and 'non-sporting' cyclists so they shouldn't have one?
Why can't they choose for themselves and either learn or continue in ignorance, like in any other activity? You don't tell people who start playing cricket that they'll have to buy a really wide bat because they can't hit the ball every time with a normal one or walkers be told their coat isn't waterproof enough to walk up hills. And unfortunately we all know that poor cycling technique isn't limited to gear selection!
It would be great if 1x models were available at a range of price points (Islabikes have been doing it since their inception). And not just flashy ones with huge cassettes that cost £80 or more to replace.
Have you thought about getting a front derailleur? They allow you to switch to a different size chainring at the flick of a lever. Fabulous invention.
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