Oval chainrings for mountain bikes are becoming more popular because of the benefits they provide riders. There are many companies now making oval chainrings for mountain biking. The primary advantage is that an oval chainring makes it a little bit easier during technical climbs where you have obstacles such as roots and rocks you need to get up and over.
Do oval chainrings really work and provide an advantage over a conventional chainring or is this just a marketing gimmick?
This article will give you the answers based on my actual experience riding with an oval chainring on some challenging mountain bike trails.
What is a Bicycle Chainring?
A bicycle chainring (if you don’t know) is a circular metal plate with teeth that engages the chain to propel a bicycle forward.
Located on the front part of the bicycle drivetrain, right underneath the seat, the number of teeth on a chainring determines how fast the bike will move.
The number of teeth also plays a role in how hard the bicycle is to pedal in a particular gear.
What is an Oval Chainring?
Instead of the traditional chainring, an oval chainring is exactly that, a chainring that is in the shape of an oval instead of being round.
Merriam-Webster’s Dictionary defines oval as “having the shape of an egg.” You may also hear an oval chainring called an elliptical chainring.
What are the Benefits of Using an Oval Chainring on a Mountain Bike?
While they may not be a new invention (oval rings have been around since the 1800s) modern oval chainrings are becoming more popular for mountain biking over the last decade.
The manufacturers of oval chainrings claim that the oval shape of the ring will help you pedal with greater efficiency and give you better traction.
They claim to help transfer the power from your pedals to the drivetrain in a more productive manner.
In simple terms, they say an oval chainring will give you better traction control and more power in certain situations.
How Do Oval Chainrings Work?
As you pedal, the oval shape causes a slight change in the cadence of your pedaling which in turn is almost like changing the gear ratio of your bike slightly with each revolution of the pedals.
Within each revolution of the pedals, you will feel a slight difference as the oval rotates. One section will be easier to pedal and the other part of the rotation slightly harder.
This is because you are actually transitioning different gearing with each cycle of the pedals.
You have what they call the “power zone” and the “recovery zone” with each part of the pedal stroke.
The recovery zones are at the top and bottom of the stroke and where you will encounter slightly easier pedaling.
I won’t go into any more detail on the physics of how they work because it really doesn’t matter to most riders. Most mountain bike riders will only care about “if” they work.
Why Do Mountain Bikers Need Oval Chainrings?
I have not tried an oval chainring on my road bikes so can’t comment but in my opinion, the reason mountain bikers should use an oval chainring is that they make riding up rough terrain and slippery surfaces easier.
Not much is tougher than trying to ride your MTB up a steep, rough single-track trail with roots and rocks in your way.
Every little advantage you can get is worth it and an oval chainring does seem to give you a little extra.
Oval Chainring Advantages
- Easier to climb hills and technical sections
- Saves energy. A scientific study showed a slight energy savings with oval chainrings
- Better rear tire traction control from a smooth pedal stroke
- Better for loose climbs with less fatigue
- A smoother pedal stroke gives you smoother power delivery
- Easier to clear technical obstacles by not getting ‘stuck’ in the dead spots of the pedal stroke
- Some riders say an oval chainring makes pedalling at a slow speed easier
- Easier to accelerate when needed
- An oval chainring is different
- Perceived advantage simply makes you a better rider
- Less stress on your knees deterring knee pain
Oval Chainring Disadvantages
- There is a scientific study showing there is no benefit to an oval chainring
- Some say chain retention is more of a problem with an oval chainring
- You don’t like how the pedal stroke feels with an oval chainring
- An oval chainring looks strange as it spins around
- You simply don’t feel it gives you any advantage over a round chainring
- You like the feel of a round chainring better
- You probably won’t feel any difference on a smooth surface
- Oval chainrings put more stress on your knees causing pain
How to choose the right oval chainring for your bike
The easiest way to pick the right oval chainring for you is to call or email the different manufacturers and ask them! They will quickly get back to you with which one will fit your bike.
How Many Teeth Should I Get on the Oval Chainring?
Since the oval chainring creates a varying gearing effect you may want to choose the same number of teeth you already have on your existing chainring if you are happy with it now.
For example, if you have a 32-tooth ring, installing a 32-tooth oval chainring will give you a 30 to 34 tooth effect as you pedal. Ask for advice when you contact the different companies.
Where Do I Buy an Oval Chainring?
There are several companies producing and selling oval chainrings including the following.
- OneUp Components
- Absolute Black
- Wolf Tooth
NOTE: There are other brands of oval chainrings so search around the internet before you buy.
Related Oval Chainring Questions
Do Oval Chainrings Look Funny?
Yes, they do look funny and if you watch the rotation movement the difference from a round chainring is very obvious.
Do Oval Chainrings Feel Strange When Pedaling?
Yes and no. Probably you will feel a slight difference in pedaling for the first 30 seconds or so.
After that, I seriously doubt you will notice any difference in the ‘feel’ of pedaling with an oval chainring.
Do I Need a Longer Chain for an Oval Chainring?
No, but ask when you contact the different manufacturers for specifics about your bike.
Will I Need Greater Chain Tension With an Oval Chainring?
No. Despite the oval design of the chainring, the chain tension does not really vary that much throughout the pedal stroke.
Be sure to ask the manufacturer about any technical questions you think of before buying.
Do Any Pro Racers Use Oval Chainrings?
There have been professional bike racers that have used oval chainrings. While this is not a mountain bike example, Chris Froome used an oval Osymetric chainring, designed by famed biomechanical engineer Jean-Louis Talo, to win the Tour de France championship.
Search the internet and see what you can find as some riders may switch back to round chainrings so I don’t want to mislead anyone with old information.
Will Oval Chainrings Work for Any Mountain Bike Rider?
I would have to say no, oval chainrings are not for everyone. Some may simply not like the slightly different feel when you pedal.
Others may not feel there is any gained advantage for them. The so-called ‘advantage’ is subtle and some riders may not notice it.
In my opinion, a very fit and very strong rider may not need the slight advantage an oval chainring seems to provide.
Are Oval Chainrings More Expensive?
Yes, in general, an oval chainring tends to be a little more expensive than a round chainring but it depends on the brand you purchase.
Are All Oval Chainrings the Same?
No, some brands make their oval chainring with more or less of the oval shape.
Will Oval Chainrings Work With a Front Derailleur?
Yes, most oval rings will work with a front derailleur but the general consensus is that your bike won’t shift as well with an oval compared to a round chainring.
A single ring system in the front will work better but if you have a front derailleur ask the manufacturer of the oval chainring what they recommend for your particular bike.
How Much of a Benefit Are Oval Chainrings?
In my opinion, you can kind of liken the advantage of an oval chainring to the perceived greater power advantage of clipless pedals.
Yes, in certain situations and for some riders there is an advantage but not everyone will realize that advantage.
If climbing on your mountain bike is one of your weak spots and you like the idea of better rear-wheel traction control, then I think you should try an oval chainring and see for yourself.
If you are like me, any advantage I can get is desired! Sooner or later you will need a new chainring for your mountain bike so why not try an oval and see if it works for you?
If you don’t like it then just put a regular chainring on the next time you need a new one. When you do you may just find that you miss the oval chainring you just took off!
For me, I have found over the last two months of riding with an oval chainring a definite advantage and I won’t go back to a regular round chainring.
With the smoother delivery of power, I am able to make it up hills easier using less energy. I am also able to clear some rock ledges now with the oval chainring that I could not make with the round one.
Oval rings just work better for me than traditional round rings.
Editors Pick For Best Oval Chainring
There are many great brands to buy an oval chainring from but my favorite is the one from OneUp Components.
Why? OneUp Components has a unique design that the inner part of the chainring is separate from the outer part that has the teeth.
This makes it possible to put quickly on a new chainring without having to take your pedal cranks off like a direct mount ring. Pretty cool!
Absoluteblack oval chainrings would be my runner-up choice. They make excellent products.
Final Word on Oval Chainrings for Mountain Biking
For the record, I didn’t notice more or less knee pain from using an oval chainring.