Buying guide · 5 min
BMX chain: which to buy, standard or half link
Standard or half link: which 1/2" x 1/8" chain suits your bike and the way you ride, and how to get the length right.
Guide updated
Quick answer: For almost any BMX a standard 1/2" x 1/8" single-speed chain is all you need: the KMC Z1 Wide is the simple option to start with and the KMC K1 Wide is the one built more for hard freestyle. Go for a half-link chain such as the KMC HL1 Wide if you need to place the rear wheel precisely in the dropouts, for example on a short-chainstay frame or when you change sprocket or chainring.
In this guide
- The three chains at a glance
- What to look for in a BMX chain, in order of importance
- KMC Z1 Wide: the simple one to start with
- KMC K1 Wide: the one for hard freestyle
- KMC HL1 Wide: the half link for precise fitting
- Standard or half link: which suits you
- Common mistakes when changing the chain
- Frequently asked questions
The chain is the part that turns every pedal stroke into speed. When it is healthy, the bike answers the first push and never surprises you on take-off; when it is stretched or badly tensioned, it skips, rattles and comes off right when you push hardest. The classic question when you replace it is whether a standard BMX chain is enough or a half-link chain is worth it.
The three chains at a glance
All three are 1/2" x 1/8" single-speed chains. Link type, joint and weight are what change.
368g
KMC
KMC Z1 Wide (chain)
- Standard
- 112 links
- Connecting link
- Link: gold
Perfect forA stock bike and a no-fuss start
411g
KMC
KMC K1 Wide (chain)
- Standard
- 110 links
- MissingLink
- Link: silver and black
Perfect forJumps, street and park every day
422g
KMC
KMC HL1 Wide (half-link chain)
- Half link
- 100 links
- Pin joint
Perfect forPlacing the wheel precisely
Data from the KMC and Amazon.es spec sheets, not from our own testing. No prices: they change often.
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What to look for in a BMX chain, in order of importance
- Size. BMX bikes use a 1/2" x 1/8" single-speed chain, wider than the chain on a bike with gears. All three in this guide are.
- Standard or half link. A standard chain alternates inner and outer links, so you can only shorten it two links at a time. On a half-link chain every link is the same and you can remove them one at a time: more room to put the wheel where you want it.
- The joint. A quick link (such as KMC’s MissingLink) opens and closes without special tools; a pin has to be pushed in with a chain tool.
- Number of links. Almost all chains come long and are cut to length. Make sure the one you buy is long enough for your chainring and sprocket.
1. KMC Z1 Wide: the simple one to start with
This is KMC’s classic single-speed chain, in 1/2" x 1/8", and KMC recommends it for BMX and fixie. If your bike is stock and you just want a new chain that works, it is the no-fuss pick.
Specs and cons of the Z1 Wide
KMC highlights its wide anti-drop design. According to the Amazon.es listing: 112 links, 368 g and a connecting link included. The link in this guide is the gold colourway.
Cons: it is the most basic of the three; if you break chains often riding hard freestyle, the K1 Wide is built for that. Pros and cons ↓
2. KMC K1 Wide: the one for hard freestyle
KMC presents it as its chain “for BMX extremes”, with reinforced tensile strength and aimed at competitors. It makes sense if you jump, ride street or park every day and want a chain that takes flat landings.
Specs and cons of the K1 Wide
1/2" x 1/8" and compatible with any single-speed drivetrain, according to KMC. According to the Amazon.es listing: reference BK1WNB110 with 110 links, 411 g, wider inner plates so it stays on, and a MissingLink joint. The link is silver and black.
Cons: it weighs a little more than the Z1 and, if you ride gently, you will not notice the difference. Pros and cons ↓
3. KMC HL1 Wide: the half link for precise fitting
This is KMC’s half-link chain, also 1/2" x 1/8" and made for BMX and fixie. Because you can remove links one at a time, you can put the rear wheel exactly where you want it in the dropouts: handy on short-chainstay frames, if you like the wheel slammed, or if you change sprocket or chainring and a standard chain ends up too short or too long.
Specs and cons of the HL1 Wide
KMC places it in its Half Link series and presents it with the “L” for long life. According to the Amazon.es listing: 100 links, 422 g, nickel-plated steel and a pin joint included.
Cons: it is the heaviest of the three and you need a chain tool to fit or shorten it. Pros and cons ↓
Standard or half link: which suits you
Pick a standard chain if…
- Your bike is stock and the wheel sits fine with your current chain.
- You want a quick link to remove it without tools.
- You want the simplest option.
Pick a half link if…
- Your frame has short chainstays or you like the wheel slammed.
- You changed sprocket or chainring and the length no longer works.
- You own a chain tool and do not mind using it.
The maths behind it: when you remove chain, the wheel moves forward roughly half of what you take out. With a standard chain the smallest step is 25.4 mm of chain, about 12.7 mm at the wheel; with a half link, half that.
Common mistakes when changing the chain
- Changing the chain without checking the sprocket and chainring: if the teeth are pointed or look like waves, a new chain can skip over them.
- Running it too tight or too loose: tight, it drags and wears; loose, it comes off. The maintenance guide has the slack reference and how to measure it.
- Cutting too much: measure twice, cut once. With a standard chain, if you overdo it there is no half link to save you.
- Fitting the quick link the wrong way round: look for the arrow or shape that shows the direction of travel, if it has one.
- Not tightening the axle nuts properly: the wheel slides in the dropouts when you pedal hard and the chain goes slack all at once.
Still tuning up your bike? See the first BMX upgrades worth making, the 5 best BMX pedals and the ODI Longneck SL or SLX grips. With your new chain on, practise the manual and bunny hop and find somewhere to ride in the skatepark, track and pump track directory. All guides are in buying guides; and the three chains with verified specs are just below.
Frequently asked questions
What size chain does a BMX use?
A 1/2" x 1/8" single-speed chain. It is wider than the chain on bikes with gears, and it is the size of all three chains in this guide.
What is a half-link chain?
A chain where every link is the same, instead of alternating inner and outer links. You can shorten it one link at a time (12.7 mm) instead of two (25.4 mm) and place the rear wheel more precisely.
Do I need a half-link chain on my BMX?
Only if a standard chain will not let you put the wheel where you want it in the dropouts, for example with short chainstays or after changing sprocket or chainring. On a stock bike, a standard chain works just as well.
How many links does my chain need?
It depends on the frame and on the teeth of your chainring and sprocket. Chains come long: put the wheel where you want it, run the chain and cut off the excess, leaving just the right slack. Take links out a little at a time.
How often should I replace a BMX chain?
When a chain checker shows it is stretched; the maintenance guide has Park Tool’s reference and how to measure it. Don’t wait until it skips: a worn chain wears out the sprocket and chainring sooner.
Why don’t you give prices or scores?
Because prices change often and we don’t want to give you a made-up score: we’d rather tell you which chain suits your bike and the way you ride. The data comes from the KMC spec sheets and the product listings.
