A chainstay is the part of the frame that goes from the bottom bracket to the rear dropouts. In other words, it’s the bottom part of the rear triangle of a bike.
Every bike has a chainstay and their size is much more important than many people think. A short chainstay will affect your bike's performance and manoeuvrability significantly, especially on a BMX or dirt jump bike.
This article will give you a lot of information on what a chainstay is, what they’re used for, how to pick a bike with the correct chainstay length and how to take care of the chainstay on your bike.
Best BMX Frames
Take a look at the best BMX frames in 2023. These are the best bike frames for street, park and dirt BMX
Where is the Chainstay?
Photo by dushan601
Every bike has a rear triangle no matter how weird the design is. The chainstay is the name for the pieces of metal tubing that go along the bottom of this triangle. There is one tube on each side of the rear wheel.
You will see the chainstay between the top and bottom of the chain when it’s on a bike.
Many bike manufacturers will reinforce or make the drivetrain side chainstay slightly thicker. When riding with gears it’s very common to hear your chain smashing the chainstay. This is less common on single-speed bikes.
Although the metal tube on the opposite side of the chain doesn’t have anything to do with the chain it is also called the chainstay. It’s not too difficult to switch the drivetrain side of a bike so there’s no point giving it a different name.
Chainstay Length and Frame Size
To measure a chainstay you should measure from the centre of the rear axle to the centre of the bottom bracket.
As you will see in the chart below, the average chainstay length is very different depending on the type of bike you ride. On a BMX, a chainstay is considered short if it’s under 13 inches. Slightly weirdly, anything over 13” is considered a long chainstay.
For many years brands never really experimented with chainstay length. It's a difficult manufacturing change for what was never a significant difference in riding feel.
Now there are so many more manufacturers and research, chainstay experimentation is much more common. BMX bikes seem to be affected most by changing the chainstay length.
I believe you can also now purchase bike frames with an insert or method of changing the chainstay length.
Average Chainstay Length on a bike
|Bike Type||Chainstay Length (AVG)|
|Cross Country (XC)||430mm|
Short vs Long Chainstays
Photo by gabrielastin
It doesn’t matter which type of bike you’re riding, these characteristics are the same.
A long chainstay will make a bike feel more stable and flowy, especially when going fast. You may feel the bike is bigger and harder to throw around when trying tricks.
Most mountain bike riders and BMX dirt jump riders should stick to longer chainstays. These riders are in the air much less and require the bike to be more forgiving than an experienced or advanced rider.
Longer chainstays will offer more variation in bike parts available to you. Bigger wheels, tires or mudguards take up room between the axle and bottom bracket. Having a short chainstay will lessen this available room and may require something to change.
What is a Chainstay Protector?
If you’re riding a bike with any amount of gears then a chainstay protector is a must. You will have noticed that your derailleur expands and contracts when changing gear. Well, along with the chain it also moves around a lot when jumping or riding rough trails.
A chainstay protector is a sticker or velcro pad that goes around the chainstay to stop the chain from damaging the paint when riding hard. Some bikes come with transparent stickers that help to prevent chips but you should upgrade to a tougher product when you can.
Photo by gabrielastin
As you can see in the image above, this bike has been ridden without an offside chainstay protector. Something like a brake cable or gear cable will have caused this after a lot of riding.
What is the Best Chainstay Protector?
Lizard Skins Velcro Chainstay Protector
You can buy chainstay protectors separately or as a frame protection kit. Lizard skins manufacture a lot of different types of bike protection. This super simple, velcro neoprene protector made by Lizard skins wraps around the chainstay to protect your frame from the chain.
This product has wider velcro and a newer backing than its predecessor, intending to give it a stronger and easier installation.Click Here to Check Best Price
AMS Honeycomb Frame Guard
This product is much more subtle. It’s designed more like a touch sticker that should be replaced every so often. You’ll notice that this is also a full-frame guard kit. You will have protection stickers for your cranks, top tube and other areas of your frame.
As you’ll see on the amazon listing, you can purchase this product in dozens of different colours. You can match your bike, go for a clear option or mix it up and go for something unique.Click Here to Check Best Price
Male vs Female Axle