The nature of cycling leaves plenty of room to form bad habits. Some bad habits make you a less efficient rider, while others take their toll on your bike and its components.
Many cyclists consider one of those bad habits to be “cross chaining” – but is it really that bad?
In this article, we’ll be covering:
- What Is Cross Chaining?
- Is Cross Chaining Bad?
- How To Avoid Cross Chaining
- When Can You Cross Chain?
- Cross Chaining: The Final Verdict
Ready for the full lowdown on the issues around cross-chaining?
Let’s get started!
What Is Cross Chaining?
Some cyclists refer to cross-chaining as “crossover gears,” but both terms have the same meaning. When you cross chain, you have changed gear so your chain is in one of two extreme positions.
You can shift so your chain is on the largest gear on the cassette while simultaneously on the largest chainring (a big-big combination). Alternatively, you could shift so the chain is on the smallest gear and smallest chainring (a small-small combination).
In either gear combination, your chain runs at a sharp angle between the chainring and cassette.
Is Cross Chaining Bad?
As you’ll discover later in this article, cross chaining isn’t that serious as long as you don’t do it too regularly.
This is especially true if your bike is set up correctly. It’s OK to do for short periods, but cross-chaining on bikes that are not perfectly aligned can cause some problems.
Other roadies will often tell you if you’re cross-chaining when you’re on a group ride. They might be annoyed with the grinding noise, but they’re probably more concerned about the harmful effects of cross-chaining for too long.
But what are these effects – and are they really that bad?
#1. How Cross Chaining Affects Drivetrain Efficiency
A commonly-held view is that cross-chaining decreases the efficiency of your bike’s drivetrain.
But in 2019, a new study experimented with a 2x drivetrain to establish how badly cross chaining really affected efficiency.
They used an 11T x 34T gear combination at a constant riding power of 250 Watts.
The friction loss in the cross-chained drivetrain was 15 Watts. This isn’t actually that much – similar to the equivalent of riding with a straight chain on a 15T x 53T drivetrain.
Even with a straighter chain line, you’ll still experience about 10 Watts of losses within the drivetrain. And because drivetrains are only 97% efficient, you only save 5 or 6 Watts by not cross chaining the 11T x 34T.
So, if you find yourself cross-chaining briefly while out on a ride, you shouldn’t have too much to worry about in terms of pedaling efficiency. If you’re a serious time-trial rider, there are tiny efficiency gains to be made by keeping your chain straight – but casual cyclists are unlikely to notice a difference over short cross-chaining periods.
#2. Riding In The Extremes Of Cross Chaining
If you were to ride your bike with the chain on the largest chainring and the largest gear on the cassette, you would likely feel a slight difference.
The chain is fully stretched to its limit and not running as smoothly as it would be when riding with a straighter chain line. You’ll also hear the extra friction as the chain grinds on the gears.
But what if you rode with your chain on the smallest chainring and the smallest gear on the cassette?
The first thing you will notice is that the chain could be quite loose, depending on your derailleur setup.
It might whip up and down as you ride over bumps, possibly hitting your chainstay or frame, and your chain can even bounce off the gears or jump onto another sprocket on the cassette.
In addition to this, you will find that the chain isn’t running as smoothly as usual. This will negatively affect your drivetrain efficiency, making you lose power. Even though the losses aren’t that great, they will slow you down slightly.
#3. Wear And Tear
When you cross chain, the edges of the chain rub the teeth of the sprocket. This means there is more friction in the drivetrain, and it makes more noise.
The additional friction generated by cross chaining will increase wear on your drivetrain components over time. The chain will grind into the gears on your cassette and chainring harder than if you were riding with a more direct chain line.
Therefore, you will need to replace components sooner than anticipated, costing you money. A dirty, unlubricated chain and drivetrain exacerbate this extra friction, acting as a grinding paste.
How To Avoid Cross Chaining
Some bikes with high-end electronic drivetrains won’t allow you to cross chain. The manufacturers program them to prevent you from setting your chain at extreme angles to protect your drivetrain components.
However, you can’t do this with a mechanical drivetrain. But it’s easy to forget that you’re riding on the large chainring, and instead of shifting off it when you get to a hill, you keep shifting up the cassette and end up on the largest gear.
So what can you do to avoid cross chaining?
Besides being mindful of your gear shifting, you can prevent cross chaining by optimizing your gear ratios relative to your speed and the terrain you ride on.
This is something that time trial riders do so they can use the middle of the cassette as much as possible. Doing this creates a straighter chain line, which is more efficient.
To do this, choose a larger chainring if you find that you spend most of your time with an angled chain.
When Is It Okay To Cross Chain?
Pro and experienced cyclists are constantly breaking the rules, and you will notice that they cross chain quite a bit. So when is cross chaining a good thing?
#1. Brief Changes In Terrain
Say you’re riding on a flat road in the optimum gear, and you approach a hill. If the hill is long, it is best to shift to your smaller chainring and into a lower gear, helping you climb it much easier.
But if it is a short and steep hill, you will want to get up and get your speed back up before your riding buddies drop you. So, in this case, cross chaining maybe your best option.
Staying on the large chainring, even if you have to change into a larger gear on the cassette, will allow you to power up the hill. You can then quickly drop down to the smaller ring to regain your speed.
Not changing to a smaller chainring will save time and energy, which is vital during a race or a long, spirited ride.
Another method you could use is to use the small chainring and a small cog for short, flat sections of a long and steep hill. But remember not to do this for too long.
#2. Cross Chain On Technical Terrain
Mountain bikers can benefit from cross chaining when riding rocky terrain, especially on downhill sections.
The issue with being in a small chainring when the trail gets rocky and drops away from you is that you can get chain slap. This is when the chain is so loose it whips around, chipping your bike’s paintwork.
But as we mentioned earlier, when the chain is too loose, it can come off your chainring. It can get trapped between the crank and the frame, making it awkward to get the chain back onto the chainring.
So, if you shift onto the large chainring, the chain will be under more tension, as most of the slack is taken away. But to make this more effective, you need to choose a medium gear on the cassette.
Doing this will keep your chain stable, but it will also mean you are in a good gear for any following short flat or uphill sections.
Many modern mountain bike groupsets feature a clutch mechanism, however, which helps to maintain chain tension without cross chaining.
#3. Cross Chain For Acceleration At The Top Of A Climb
Sometimes pros cross chain near the top of a climb when it is faster to do so than to change gear on the front derailleur.
This is especially helpful if there is an immediate descent following the climb. They can quickly shift into a higher gear to accelerate down the hill.
Cross Chaining: The Final Verdict
Clearly, your bike isn’t suddenly to suddenly implode if you realize you’ve accidentally been cross-chaining for a few hundred meters.
Besides, it can even be a legitimate strategy at certain points in a race to be able to lay down the power at the opportune moment.
However, it’s still best avoided as much as possible. While there’s unlikely to be a dramatic sudden failure, over time, cross-chaining will gradually increase wear and reduce your cycling efficiency.