drivetrains – Bicycle 2 Work

The trend of 1x drivetrains started with mountain bikes and then slowly oozed into the Cyclocross world. Now, roadies are beginning to discover the benefits – and drawbacks - of using a 1x drive train on their road bikes, as well. While it is an excellent option for many circumstances, is this type of drive train right for your road bike? Riding a road bike with a 1x drivetrain is great for saving weight, preventing chain drop, and simplifying your shifting. You might love racing crits with a 1x. However, it isn't a great choice if you're riding both flats and hills on the same ride. If both flats and hills are involved, your drivetrain won't be as efficient, and neither will your cadence. (Source) After you look at the pros and cons of riding a road bike with a 1x drivetrain, you'll be able to decide if this is the right choice for you. This article will discuss the pros and cons of a 1x drive train for road bikes. We'll look at all the reasons you might want one and some of the reasons you might not. By the end of the article, you'll have a pretty good idea of what works best for you. But first, we'll explain the difference between a typical road bike drive train and a 1x drive train. What's the Difference Between a Typical Road Bike Drive Train and a 1x Drive Train? What is a Drivetrain? The drivetrain of your bike is all of the parts that work together to make your bike go. To make it really simple, you push down on the pedals, which turn the cranks. The cranks turn the chainring, which pulls the chain along. The chain turns the rear cassette, which is attached to the wheel, pushing the bike forward. There are a few extra pieces in there to help things go smoothly, such as the rear derailleur, jockey wheels, etc. All of these pieces are your drivetrain. Standard 2x Drive Train A typical road bike drive train is made up of 2 or 3 chainrings in the front and a variety of cogs (collectively known as the cassette) in the back. The combination of chainring and cogs that you choose will make it easier or harder to pedal, also known as gearing. For example, a Canyon Endurace will have two chainrings in the front. It comes with a 50/34, which means it has a 50 tooth chainring and a 34 tooth chainring. The gear range on the cassette is 11-34. Your easiest combination would be to use the smaller chainring in front and the largest cog in the back, giving you a 1:1 gear ratio. This gear ratio means that you get one rotation of the wheel for every turn of the pedals. This is great for climbing steep ascents. The hardest combination would be 50 in the front in and 11 in the back. It's harder to turn over the pedals, but each pedal stroke will push you further. You would use this gearing to smash down the descents or speed along the flats. Now that you know what a standard 2x drivetrain is, let’s look at what a 1x drivetrain is. 1x Drivetrain When I purchased my first cyclocross bike, I got a great understanding of how a 1x drive train works. It's basically the same as a standard drivetrain, only you have fewer choices of gears. (Source) For example, rather than having 2 or 3 chainrings in the front, you'll just have 1. My CX bike, a Liv Brava, has a 40t chainring in the front and an 11/34 cassette in the back. So you'll get plenty of gears in the mid-range, but you won't have the high or low end that you would have on a standard 2x drivetrain. If you wanted, you could change out the chainring in the front for a larger one. This would give you harder gears for descending on flat riding. Or, you could choose a smaller one, which would give you easier gears for hill climbing. You could swap out the back cassette (if the space on your bike permits you to do so) for one with a larger range. This would give you more options, but there would be larger jumps between the gears so the shifting and your cadence wouldn’t be as smooth. Now that you can see the difference between a 1x and a 2x drivetrain, let's look at the pros and cons of using a 1x drivetrain on your road bike. Pros of a 1x Drivetrain Simplified shifting The first, and maybe the most important benefit, you'll get here is simplified shifting. You shift to a harder gear when the terrain is easy and to an easier gear when the terrain is hard. So basically, you shift up or down, which is great for newbies and people who don’t want to have to concentrate on shifting. On a 2x drivetrain, it's a little bit more complex. When you ride a 2x, you have a few gears in the middle range that are duplicated. Some of the duplicated gears put too much tension on the chain, so you don't really want to use them. So when you shift chainrings, you'll also need to shift a couple of gears on the cassette, as well. Some people call this Alpine shifting – you shift up one on the chainring and down two on the cassette. If you shift down on the chainring, you shift up two on the cassette. This shifting method gives you a better transition from one gear to the next, but it's a more complicated means of shifting than if you just use a 1x drivetrain. https://twitter.com/NorthRoadCycles/status/1457788388900175876 Lighter weight Another benefit to a 1x drivetrain is that it saves weight on the bike. Chainrings and derailleurs add weight, so if you're a weight weenie or you just want your bicycle as light as possible, you might just prefer a 1x drivetrain. It isn’t a lot, but you might save around 200 grams by choosing a 1x over a 2x. More aerodynamic Some folks tout that the bike is more aerodynamic without the extra derailleur in the front. That may be true, but the aerodynamic gain is going to be pretty minimal since the derailleur sits close to the frame, anyway. But if you are all about minimal gains, this is one to consider. More clearance for bigger tires Road bike tires tend to be pretty skinny, but if you want the flexibility of putting some wider tires on your road bike, you might consider a 1x. Dropping that front derailleur gives you a little more tire clearance, so you can squeeze some gravel or cyclocross tires onto that road bike and call it a day. Fewer chain drops A great benefit to the 1x setup is there is less chance of dropping your chain. There's also less chance of your chain getting stuck between two gears. Even on my best 2x drivetrain, I experience chain drops when I accidentally shift into the smallest chainring in the front and the smallest cog in the back. Yep, this is a no-no, and will definitely send my chain where I don't want it to go. On my 1x, though, I've never had to suffer that particularly embarrassing mechanical issue. It is something I appreciate about my 1x bike. Less moving parts to break down Let's face it, fewer moving parts means fewer parts to break. You'll have less maintenance, too, so you can keep your bicycle out of the shop and out on the road. It is simply less to worry about. Better in bad weather If you ride in the rain, chances are you'll be picking up a bunch of mud, too. There's nothing like trying to shift with a front derailleur that's packed full of mud and road grime. With a 1x, you won't have to worry about your front derailleur getting all gooked up. So a 1x is worth considering if the bulk of your road riding is in wet, muddy conditions. Better for crit racing If you are racing crits, a 1x might be all you need. Crits tend to be fast, short races with sharp turns. So you'll be able to shift fast, save weight, and sprint hard without worrying about your gears. So there are plenty of reasons to use a 1x on your road bike, and they are quickly gaining in popularity. However, there are also plenty of reasons you might not want a 1x drivetrain. Let's take a look at a few of the cons. 1x drivetrain road bikes can be a perfect choice for simplicity and reducing the risk of any technical issues on your ride Cons of a 1x drivetrain Smaller gear range If you are using a 1x drivetrain, you'll have a smaller gear range. If you're using a 40 in the front and an 11-34 in the back, you'll be limited to mid-range gears. But once you switch to the 2x in the front, you'll have more gears at each end of the spectrum to choose from. On the other hand, you could select specific gearing for a particular ride or race. In that case, you might have all climbing gears, but then you would spin out on the descents. Or you might have gears for speed, but you'll never make it up the hill. 1x drive trains on a mountain bike have a wide range of gears with big jumps in between. You could use this on your road bike, but your cadence would suffer as a result. In addition, you simply don't have as many choices for gearing in-ride with a 1x setup as you would with a 2x drivetrain. Less efficient cadence Your cadence will take a big hit with a 1x setup. For example, if you choose gearing that is suitable for hill climbing, you'll have to spin at a very high cadence to keep up with your 2x-riding mates. Such a high cadence is going to tire you out fast. On the other hand, if you choose gearing meant for speed, you're going to really suffer getting up the hills. You might even need to hike-a-bike if the gradient gets too steep. If nothing else, you'll be grinding those gears at a low cadence, which could blow out your knees. Less speed on the flats As I mentioned before, you'll have trouble getting up to speed on the flats with a 1x. Weight is less of an issue on flat roads, so the minimal gains won't be worth it next to the extra gearing you can get with a 2x. You'll need a fast cadence to keep up. Less efficient drivetrain Interestingly, a 1x drivetrain is technically less efficient than a 2x. This loss of efficiency is because the angle of the chain from the chainring to the cassette is greater on a 1x than on a 2x. As a result, it causes more friction on the chain, which is less efficient. So if chain efficiency is important to you, you might want to stick to the tried and true 2x drivetrain. More difficulty racing on flats and hills A 1x drivetrain is fine if you're racing the flats, but if you are racing a combination of flats and hills, you're going to have trouble. You just can't keep an efficient cadence and have enough gears for climbing and sprinting both. So you'll have to prioritize gears or cadence, which isn't very helpful on race day unless everyone is in the same boat. Final Thoughts The choice between a 1x drivetrain and a 2x drivetrain really depends on the type of riding you do. If you just ride for fun, the difference is probably negligible, and you might love the simplicity of a 1x. On the other hand, if you primarily ride flats or crit races, you might absolutely love the simplified shifting of a 1x drivetrain. But if you'll be hitting the hills, racing on flats and climbs, or really want a bike that can do every type of road ride and race, you're probably better off with the flexibility of a 2x drivetrain.