The segmentation of bicycle types is unstoppable. While 30 years ago we used only a few types (there were mountain bikes and a small group of road bikes), today there are dozens of bicycle types. (I wrote more about this in this article.)
The birth of gravel
One of the newest types of bicycles is gravel. Why was it invented? If we assume that gravel is not just a PR idea stemming from manufacturers’ increased investment, but rather satisfies a real need, then we would say that the existence of gravel is actually the opposite of segmentation development. We needed a bike that could replace several types. That is, something that could be used for fast travel on asphalt roads, hiking on gravel dirt roads, through forests and mountains, and the more daring could even “mount” it. So a mule, a good bike for everything was needed. They often say that gravel is the love child of the mountain bike and the road bike, but this is not true. It became more of a durable, comfortable road bike.
Of course, the basic shape had to be invented for this. It is no coincidence that this was a road bike. After all, on the one hand, fast and sporty “progress” and the geometry serving this were given to this type. On the other hand, the predecessor of the garvel, the CX bike, was developed from the need for road racers to be able to “compete” off-road during the off-season. The geometry of mountain bikes is unsuitable for fast progress (not for hiking), and the comfort, sluggishness and weight of touring bikes are also lacking, so the filigree road bike remains.
What makes gravel gravel?
First of all, they made the geometry more comfortable. The roadbikes already had a more comfortable (endurance – touring) version, and this became the starting point. They made the frame profile higher, with a larger stack, a shorter top tube (reach – I wrote about the importance of reach and stack in this article!), and the position became even more comfortable for the road bike than for the cross-country bike. This won over a lot of people, as a lot of people didn’t ude roadbike because the position was uncomfortable.
Off-road obviously requires much more durable tires and rims. The rims have become stronger, the rubber thicker and more grippy. To accommodate the thicker rubber, the frames have been slightly modified. The width and capacity of the front and rear forks have increased. While you rarely put a 32 mm wide tire on a “regular” road bike, a 47/50 mm wide tire can fit on a gravel bike (I wrote about tire sizing here!).
The handlebars have remained the same as those used on the roadbikes, as they have the most grip options among the handlebars available today. It is a different matter whether a wide handlebar is better for off-road use, for balancing at slow speeds. The 42 cm width of the handlebars is negligible compared to the 60-70 cm of a mountain bike or a straight handlebar. Therefore, for example, it does not matter what purpose you use the gravel bike for: on a forest trail, you will not balance with a 42 cm handlebar as well as with a 70 cm mountain bike handlebar.
In addition, gravel bikes were also equipped to receive luggage, as they quickly realized that this form of cycling could be used quite well by touring cyclists who mainly use asphalt, gravel, and mountain trails. Bikepacking-type cycling quickly discovered gravel, and the mule solution. And the market responded to this: it equipped the bikes with mounting points for the rear luggage rack, these were also added to the front fork, and companies producing quality bags (handlebar bags, large saddle bags, wallets that can be hung on the top tube, etc.) began to appear on the market.
The most important change: the drive system
The biggest transformation in the creation of gravel, however, involved the drivetrain. This resulted in changes that make it all the more important what you plan to use your specific gravel bike for. To understand what kind of drive is optimal, you need to understand the essence of shifting and driving.
While a modern road bike has a 2×11/12 gear system, which means that you will find two cranks at the front and 11 or 12 gears at the back, off-road bikes now have a 1×11/12 system. This difference simply stems from the way it is used. Road riding requires a fairly wide gear range, which means that on the one hand you need to be able to go very fast (i.e. a 4-5x gear ratio is needed), and on the other hand you use it on very steep roads, with the smallest gear ratio possible. Figuratively speaking: For fast travel, you need a front sprocket with as many teeth as possible (today this usually means 50-53 teeth), and a rear sprocket with as small a number of teeth as possible (10 or 11). And uphill, it’s the other way around: you need a front sprocket with as few teeth as possible and a rear sprocket with as many teeth as possible. This shows that this cannot be solved with a front disc, because with current technology the chain can only handle 11-12 speed ranges.
Which is better, 1×11 or 2×11?
The upper and lower gear ratios of 1×11 systems (i.e., they have a wide gear range) are not that bad, but one very important aspect remains. For road bikes, the basic requirement is that there should be no big jumps between the gears, since when riding fast (with a large chainring in the front), “smooth” shifting and precise, accurate gear range setting are very important. Too big a jump between each gear is not tolerated by the human musculature. A jump of 15-20% cannot optimally set the desired gear ratio (when it is not too difficult to pedal, but the legs do not spin unnecessarily).
To illustrate this: Let’s say you’re riding at 35-40km/h, with a large chainring (52) in front and a small sprocket (11) in the back. This means that by the time you turn the large front sprocket, the small rear sprocket (and the wheel itself) will have turned almost 5 times, meaning the rear wheel is spinning quite a bit, but you’re barely turning the large sprocket. When you accelerate, you only need a little torque, and you’re going with momentum. If the terrain changes, for example the road is climbing, you need to shift back for optimal riding feel and power (that’s what the shifter is for).
Of course, this also depends on the strength of your legs, but sooner or later everyone will come to the angle change in the road where you have to shift back. However, the shift back cannot be too large, as then your legs would start spinning, which is also not comfortable. Therefore, on a road bike, the smallest possible difference in tooth range on adjacent discs is optimal. On a road bike, this means one gear in the first 4-6 rows, while on a mountain bike, for example, each shift can easily jump 3-5 gears (which sometimes means 25+%).
Of course, if a flat road becomes a 10% incline, the situation is different, as there is no need for fine-tuning, but a completely different torque and speed, which you achieve by changing the front derailleur to the small chainring (34 teeth) and putting the chain on the larger sprocket (32) at the rear. This changes the gear ratio, achieving less torque and higher speed, meaning that while your leg is spinning fast in front, the rear wheel is “barely” moving (at least compared to the previous state).
The mountain bike gear system
With mountain bikes, however, the situation is completely different. There is no need for a wide gear range, as mountain bikes are designed to be ridden mostly uphill in forests, on trails, on rough ground and in off-road conditions, which usually does not require high speed, but requires high torque. On the other hand, there is no need for very fine shifting with a small number of teeth: for slow travel, a specific, wide gear range is much more important than fine shifting.
That’s why the 2×11 (or earlier 3×8/9) system died out the fastest for mountain bikes, because there’s simply no need for a large gear range. That’s why – logically – they switched to a 1x drivetrain. This means that there’s no derailleur at the front, but there’s a relatively small number of teeth, and at the back you have an 11 or 12 system with relatively large jumps, where the extreme value between the small and large cogs is significant (11-42 for example). That way, if you have to, you can go fast, which means that you can shift uphill (say, with a 36/11 gear range), but you can go uphill quite well and easily thanks to the large rows with increasingly larger numbers of teeth (36/42).
The Gravel Drivetrain Dilemma
In the case of gravel, the most important question is whether our bike should have a single chainring system or a double chainring system? As we have seen, both are existing, acceptable technologies, they have a right to exist, both have their advantages and disadvantages. However, from your point of view, the most important thing is: you need to know what you will use the bike for? Because there are significant differences between the two drive systems.
The gravel market is moving towards 1x systems today, which is logical: it is much simpler, there is no need for a front derailleur, the risk of the chain falling off is smaller, almost a fraction, and the bike will also be lighter. The disadvantages obviously stem from the problem described above: the smaller gear range and the feeling of a shifting “hole”. You have to think about what you need! With the 1x system, you get a road bike that can be used well on the terrain, with which you can mostly go fast, but you can only use it as a “road” bike with significant compromises. With the 2x system, you get a basically road bike that you can use well with narrower tires for fast asphalt riding and which is also good on gravel and forest roads, but is highly compromised on rougher, mountain climbs.
So which one is better now?
Basically, the way you use it decides everything. Since gravel is a comprehensive solution, let’s look at this from the perspective of who would use the bike for what!
We can safely say that if you come to gravel riding from MTB and would rather use your bike in the forest, on single-track, rocky roads, and trails, but also need to occasionally go fast on gravel, a 1x drivetrain is better. On the other hand, if you come from roadbiking and gravel is more about being able to push the bike’s usage area to gravel and dirt roads, so don’t be embarrassed, if you find one, you need a 2x system.
If you are going on a bike tour, say bikepacking, you can use both, the question here is more where you are going? For example, if you are going into the mountains with larger packages, then a 2x system is necessary, since a bike weighing about 20-30kg with packages requires a large gear range. But if, for example, you are planning a multi-week tour in remote places, then the reliability of the 1x system may be better (although the front derailleur usually does not break).
However, one thing is very important: if you buy gravel, think carefully about this issue, because conversion is a significant expense.
My subjective opinion
My subjective opinion leans towards the 2x system, but there are at least as many debates on this topic as there are on the Shimano vs. Campagnolo system. Each side is convinced of its rightness and will not let anyone down.
On the one hand, I don’t see 1x systems as simpler. The first derailleur is obviously an additional failure factor, but it gives much more compared to that. It’s true that I don’t use the gravel on trails, I don’t “mount” it with it, but rather bought it as a complement to the road bike (not a full gravel bike, but more of an all-round bike – more on that below). I’ve mounted a lot, even on 2x/3x systems, and I’ve never had a problem with it. But then I also used a 1×11 system for 4 years, while now I’m on the road with a 2×11 system.
I really liked the simplicity of the 1×11 system. I had to manage one derailleur, I didn’t have to think about the variations, whether to change it now or not. 11 speeds were a given. With the 1x system, you can shift by instinct, by feeling. However, no matter how fast you could go with it and climb larger hills (so the gear range was large), the shifting “hole” was too big. I found myself in a situation where I couldn’t find the optimal gear countless times. It’s true, I didn’t ride with it, but rather cycling on asphalt, so it replaced road functions. But the 15-20% differences were too big, no matter how you look at it.
Moreover, there were times when the climb was steeper than I liked, but this can be overcome with well-chosen gears and chainrings. Of course, you have to decide what you normally put in front. Since the rear has 11/12 gears, you can “adjust” with the front chainring whether you want to use the bike for climbing or for going fast.
I’ve never had a problem with this on the roadbike, the 2×11 system does its job with easy. Since it’s electronic (di2), I usually only have to deal with the rear derailleur, because di2 can be programmed to shift automatically (when it reaches a certain number of teeth on the rear, it shifts the front derailleur). That’s why I really like di2: here you don’t have to deal with the front derailleur and you still have a 2×11 system.
New features, interesting features: hub, Classified system
So there are countless questions to consider and we haven’t even talked about hub derailleurs as a possible alternative (for example, the 14-speed Rohloff or the 11-speed Shimano Alfine system). Hub are not a modern invention, they usually work with a belt drive, since a chain is not needed (since the shifting is in the hub). And a carbon belt is much better than a chain. It is more direct, you can feel the drive better with it. The disadvantage of the belt (which is why it couldn’t spread) is that it requires a hub derailleur (since the belt cannot be changed, it cannot turn left or right). However, hub derailleur technology is still rudimentary and expensive, even the best ones are “only” 14-speed and 1200 euros.
The Classified system was released in 2020
, which is practically a “halver” in the rear hub, meaning that if you install it, it doubles your 1×11 system without a front derailleur. It works electronically, shifts in seconds and is completely wireless. It’s a brilliant solution, the downside is the price, 2400 euros (about 880 thousand HUF), which doesn’t just make a front derailleur or a complete di2 system, but also a complete carbon bike equipped with di2…
The rise of versatile (allround or allroad) bikes
With the rise of gravel bikes, a very interesting trend is emerging: more and more manufacturers are realizing that in the road and gravel segments (or very close to it) all-around (or also known as allroad) bikes could be produced, i.e. bikes suitable for all roads and uses. A bike that can be used in a wider range, flexibly, and versatilely, which is good for 2-3 functions, almost without compromise. That means you can go fast on asphalt, it won’t get confused on gravel, and you can even hike with it, even in the forest.
Of course, the question is how much gravel and allround differ from each other, since they have almost the same function, but the fact is that allround bikes are already produced by several manufacturers.
Of course, we could say that there is no difference between gravel and all-round bikes, but I think everyone who has read the previous articles can see that this is not true. A gravel bike is a good compromise, but from a road riding perspective, it is not perfect for a road bike either (due to drivetrain, geometry, wheels, etc.).
An all-round bike, on the other hand, can be just as good – with much less compromise: its geometry is not so blatantly gravel, it is much closer to the frame geometry of road bikes, the wheel width tolerance is better than that of road bikes, and its drivetrain is a 2x system, so it is more usable.
Wheel size: 650b or 700c, maybe both?
Moreover, by adding different rim and wheel sizes, you can convert from gravel to road and vice versa in an instant. Because these bikes can usually be used with 650b and 700c, i.e. 27.5 and 28 wheel sizes. The wheel size is basically a frame issue, it simply has to fit in the frame (and obviously you don’t need rim brakes, but disc brakes).
The 27.5-inch wheel (650b) is more typical for mountain bikes (of course, there are 700c and 29-inch versions), while the 28-inch is more for road and gravel. The 27.5-inch wheel (rim) is usually fitted with wider, more knobby tires (because that’s what you need for off-road riding), while the 700c rim is fitted with smoother and thinner tires (that’s what you need for road riding). The characteristic of all-round bikes is that they can be used with both rim (wheel) sizes, which is why they are truly versatile.
Of course, such a bike has its limitations, as it doesn’t feel so good on single-track, rocky trails, but this question also arises with gravel.
Although there is no doubt that they are very close to each other and the difference is quite small, but looking at the success of gravel, I think that the future belongs to all-round bikes. With one of these, you don’t need two bikes, at most two sets of wheels.
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