I believe there’s too little talk about BMX chain alignment.
Why?
Because if your chain isn’t straight, all three will suffer: the chain, the sprocket and the rear cog.
You want your parts to last you a long time, right?
So keep that chain straight!
The only time you might not need to care about the alignment that much is if you run a really loose chain.
But don’t do that.
It doesn’t look good, and the sound that the chain makes when it hits the frame is THE WORST.
Anyway, getting that chain straight isn’t just about riding smoother: It’s about keeping your bike in good shape and keeping you safe while you’re out there shredding.
This post covers:
- How to check if your BMX chain is aligned
- Step-by-step guide to aligning your BMX chain
- Common BMX chain alignment mistakes
- Maintain proper BMX chain alignment for longevity
- Conclusion: Keep your chain straight!
- FAQs about BMX chain alignment
How To Check If Your BMX Chain Is Aligned
Checking if your BMX chain is properly aligned is pretty simple.
Here’s how you can do it:
1. Visual Inspection
This is the first thing you’d want to do.
Stand behind your bike and look along the length of the chain.
The chain should run in a straight line from the front sprocket to the rear cog. If you notice the chain bending or veering to one side, it’s misaligned.
2. Spin The Cranks
Lift the rear wheel off the ground and spin the pedals. (My favorite method is to flip the bike around and let it sit on your handlebar and seat.)
Watch the chain as it moves. It should run smoothly without wobbling or making unusual noises.
If you hear clicking or notice uneven movement, there’s likely a problem with alignment.
3. Check For Chain Tension & Resistance
While spinning the cranks, check how the chain feels. There should be a little slack, but it shouldn’t be too loose or tight.
Too much tension or slack can be a sign of misalignment.
Moreover, when riding slowly or pedaling by hand, you shouldn’t feel any resistance or “drag.”
If it feels harder to pedal than usual or the chain feels like it’s catching, that can indicate the chain isn’t aligned properly.
Note: I run my chain slightly tighter but still ensure it’s aligned.
4. Rear Wheel Alignment
Check if your rear wheel is centered in the dropouts.
If it’s off-center, it will throw off the alignment of the chain. And this is a common cause of chain misalignment.
Step-by-Step Guide to Aligning Your BMX Chain
Step 1: Loosen The Rear Wheel
First, let’s loosen up the rear axle bolts.
You don’t need to take them off completely, just enough so the wheel can move a little bit.
This is gonna give us the wiggle room we need to get everything aligned.
Step 2: Align The Rear Wheel
Now that the axle bolts are loose, it’s time to center the rear wheel in the frame’s rear triangle.
Look at your wheel from behind – it should sit perfectly in the middle of the frame.
If it’s off to one side, that’s what’s messing up your chain alignment.
If your wheel isn’t centered, the chain will pull to one side, making your ride feel wonky.
Step 3: Adjust Chain Tension
Next up—chain tension!
You want the chain tight enough that it doesn’t slap around but not so tight that it feels stiff.
A little slack is good, especially if you want to do crankflips.
Pull the rear wheel back or forward slightly in the dropouts to adjust this.
This is even easier to do if your frame has built-in chain tensioners.
Leave enough room so the chain has enough play to run smoothly.
Step 4: Add Or Remove Crank Spindle Spacers
As a beginner, I made the mistake of adding too few or too many crank spindle spacers a number of times.
Spindle spacers are little washers that sit on your crank spindle and help keep your chain aligned. They come with the cranks.
If your chainline is off (like if the chain isn’t sitting straight between your front sprocket and rear cog), adjusting these spacers can help.
Adding a spacer can push the crank out a bit, while removing one can bring it in.
This helps align the front sprocket with the rear cog so the chain runs straight.
It sometimes takes a few tries to get it straight, but it’s worth the effort.
Step 5: Spin & Check
Now, give the pedals a good spin.
Watch the chain closely – it should move smoothly without wobbling or making any weird noises.
You might need to make more adjustments if you hear clanking or see the chain bouncing around.
Keep tweaking until it’s running clean.
Step 6: Tighten The Axle
Once everything looks good, tighten those rear axle nuts back up.
But do it carefully – sometimes tightening the nuts can shift the wheel slightly, messing up all the alignment work you did.
Note: That’s why it’s important that you always start tightening on the rear cog side.
But don’t tighten it all the way. Tighten it just enough so it holds the wheel, then tighten the other side, and then go back to the cog side.
After that, do one final check on the chain tension. If all’s good, you’re done.
Common BMX Chain Alignment Mistakes
I’ve made pretty much all of these mistakes regarding chain alignment in the past.
And even now, I sometimes completely forget and only notice something’s off after my first session.
But that’s OK.
Okay, here’s what to avoid:
- Misaligning the rear wheel: If your rear wheel isn’t centered, the chain will be crooked and wear unevenly (including both sprockets). Step back and make sure the wheel’s in the middle.
- Ignoring the chainline: If the crank position is off, the chain will be crooked. Pay attention to the chainline and those crank spindle spacers to keep things straight.
- Neglecting crank spindle spacer adjustments: Spindle spacers might seem small, but they’re key for alignment. Adjusting them can prevent a lot of hassle.
Maintain Proper BMX Chain Alignment For Longevity
Keeping your chain dialed in long-term is all about regular maintenance.
Here’s how to stay on top of it:
- Regular checks for chain tension & alignment: Lift the rear wheel, spin the pedals, and see if the chain is still straight. Adjust tension or alignment if needed. (It’s a quick and easy check that keeps things running smoothly.)
- Lubricating the chain: A well-lubed chain lasts longer and gives you a smoother ride. Clean off any gunk, apply lube evenly, and wipe off the excess. (I suck at this one – need to improve.)
- Replacing worn parts: If your chain is stretched or the sprocket teeth are sharp, it’s time for a replacement. Don’t wait for something to snap mid-ride!
Conclusion: Keep Your Chain Straight!
Alright, dude, here’s the bottom line – keeping your chain straight isn’t just about having a smooth ride; it’s about ensuring your BMX performs at its best and stays safe while you’re out there.
A well-aligned chain will make pedaling easier, tricks cleaner, and prevent annoying chain slips or worse.
My best advice?
Check your chain alignment and tension regularly, like a quick routine after a few sessions.
It doesn’t have to be a big deal, just a few minutes here and there to keep things tight.
Honestly, a little bit of maintenance now will save you so much trouble later on.
Keep that chain straight, and you’ll be able to focus on what really matters – riding hard, landing new tricks, and just enjoying every session to the fullest.
FAQs About BMX Chain Alignment
How tight should my BMX chain be?
Okay, so your chain should be tight enough that it doesn’t slap around but not so tight that it feels like you’re fighting it when you pedal. Even if you want to do crankflips, you don’t want your chain to be too loose.
What are the signs of a misaligned chain?
If you hear weird noises like clanking or grinding when you pedal, that’s a sign something’s off. Also, if the chain wobbles or keeps loosening up even after you tighten it, you probably have an alignment issue. And if your rear wheel isn’t centered, that’ll throw the chain alignment off, too.
Is it normal for the chain to skip when it’s misaligned?
Yes, chain skipping is a classic symptom of misalignment. If your chain isn’t sitting straight between the front sprocket and rear cog, it will likely hop around, especially when pedaling hard. It can also skip if the chainline is off or if there’s too much slack.
Further reading:
- Don’t Install BMX Half Link Chain Wrong
- Best BMX Chains
- Best Half Link BMX Chains
- Best BMX Sprockets
- Best BMX Chain Breaker Tools
