You’re riding along and suddenly psssssss. Your tire goes flat.
Maybe you hit glass. Maybe you ran over a thorn. Maybe your tube just decided today was the day to give up.
Whatever the reason, you’re stuck with a flat tire and you need to fix it.
Here’s the good news: fixing a flat is easier than you think. You don’t need to be mechanically inclined. You don’t need a ton of tools. And once you’ve done it a few times, you can fix a flat in 10 minutes.
This guide walks you through exactly how to fix a flat tire, what you need, how to remove the wheel, how to change the tube, and how to get back on the road.
By the end, you’ll know how to handle flats yourself instead of calling someone to rescue you.
What You’ll Need
Before we get into the process, here’s what you need to carry with you:
Essential Tools:
1. Spare Tube
Always carry at least one. Get the right size for your tire (it’s printed on the tire sidewall, something like 700x25c or 26×2.0).
Cost: $5-12 per tube
2. Tire Levers (2-3)
Plastic tools that help you pry the tire off the rim. Don’t try to use screwdrivers, you’ll damage the tube and rim.
Cost: $5-10 for a set
3. Pump or CO2 Inflator
You need to inflate the new tube. Options:
- Mini pump – Slower but reusable ($15-30)
- CO2 inflator + cartridges – Fast but single-use ($10-15 for inflator, $3-5 per cartridge)
4. Multi-Tool (Optional but Helpful)
To remove wheels if you have quick-release or thru-axles that need a tool.
Cost: $15-30
Nice-to-Haves:
Patch Kit
For fixing the punctured tube later (so you have a spare again). Not essential for roadside repairs.
Cost: $5-10
Gloves
Keep your hands clean. Not required, but nice.
Step 1: Identify Which Tire is Flat
This sounds obvious, but check both tires. Sometimes the rear feels flat when it’s actually the front (or vice versa).
How to check:
Squeeze the tire. If it’s squishy and doesn’t hold pressure, it’s flat.
Most of the time, it’s the rear tire. The rear carries more weight and picks up more debris from the road.
Step 2: Remove the Wheel
You need to get the wheel off the bike to access the tube.
For Front Wheels:
If you have rim brakes:
- Open the brake quick-release (little lever on the brake caliper that releases tension)
- Open the wheel quick-release (lever on the wheel axle)
- Lift the bike and the wheel should drop out
If you have disc brakes:
- Open the wheel quick-release or loosen the thru-axle
- Lift the bike and slide the wheel out
- Important: Don’t squeeze the brake lever once the wheel is off (the pads will close and be annoying to reset)
For Rear Wheels:
This is slightly trickier because of the chain and gears.
Steps:
- Shift to the smallest cog (hardest gear) – This makes the chain looser and easier to work with
- Open the brake quick-release (if rim brakes)
- Open the wheel quick-release or loosen the thru-axle
- Pull the derailleur (the gear mechanism) backward to create slack in the chain
- Lift the wheel up and out, threading the chain off the cassette (the gears on the rear wheel)
Pro tip: Take a photo of how the wheel sits in the frame before removing it. This helps when you put it back.
Step 3: Remove the Tire from the Rim
Now you need to get the tire off the rim to access the tube inside.
How to Use Tire Levers:
- Step 1: Deflate the tire completely
If there’s any air left, let it out by pressing the valve. - Step 2: Push the tire bead away from the rim
Squeeze the tire all around to loosen it from the rim. This makes the next step easier. - Step 3: Insert the first tire lever
Slide a tire lever under the tire bead (the edge of the tire) and hook it onto a spoke. - Step 4: Insert the second tire lever 4-6 inches away
Slide it under the tire bead and pull down. The tire should start to come off the rim. - Step 5: Slide the lever around the rim
Once you have some tire off, you can slide the lever around the rim to pop the rest of the tire bead off. - Step 6: Remove one side of the tire completely
You don’t need to remove the entire tire, just one side. Leave the other side on the rim.
Step 4: Remove the Tube
- Step 1: Pull the valve out of the rim hole
Unscrew the valve nut (if there is one) and push the valve through the rim. - Step 2: Pull the tube out from under the tire
The tube will come out easily once the valve is free. - Set the old tube aside. You can patch it later at home.
Step 5: Check the Tire and Rim for Debris
This is critical. If you don’t find what caused the flat, you’ll just get another flat immediately.
How to Check:
- Step 1: Run your fingers (carefully!) along the inside of the tire
Feel for glass, thorns, staples, wire, or anything sharp embedded in the tire. - Be careful whatever punctured your tube is sharp.
- Step 2: Visually inspect the outside of the tire
Look for cuts, embedded debris, or damage. - Step 3: Check the rim tape
The rim tape covers the spoke holes inside the rim. Make sure it’s not torn or shifted. Exposed spoke holes can puncture tubes. - Step 4: Remove any debris
Pull out glass, thorns, or whatever you find. If the tire has a big cut (more than a few millimeters), you might need to replace the tire (or use a tire boot see below).
Step 6: Install the New Tube
- Step 1: Slightly inflate the new tube
Put just a few pumps of air in it, enough that it holds its shape but isn’t firm. This prevents it from getting pinched during installation. - Step 2: Insert the valve through the rim hole
Start by pushing the valve stem through the hole in the rim. - Step 3: Tuck the tube under the tire
Work your way around the rim, tucking the tube up under the tire. Make sure the tube isn’t twisted. - Step 4: Check that the tube isn’t pinched
Before you put the tire back on, make sure the tube isn’t caught between the tire bead and the rim anywhere. Pinched tubes = immediate flat.
Step 7: Put the Tire Back on the Rim
- Step 1: Start opposite the valve
Begin pushing the tire bead back onto the rim, starting across from the valve. - Step 2: Work your way around
Use your hands to push the tire bead back onto the rim. It should go on fairly easily. - Step 3: The last section will be tight
The final 6-12 inches of tire will be tight and hard to get on. Use your palms to push it on, working from both sides toward the middle. - Avoid using tire levers here if possible (they can pinch the tube). Use hand strength.
- If you absolutely must use a tire lever, be very careful not to pinch the tube.
- Step 4: Push the valve up into the tire
Once the tire is on, push the valve up into the tire slightly, then pull it back down. This ensures the tube isn’t trapped under the tire bead near the valve.
Step 8: Inflate the Tire
Step 1: Inflate to about half pressure
Put some air in and check that the tire is seated properly on the rim. Look at the bead line (a molded line on the tire sidewall). It should be even all the way around the rim.
Step 2: If the tire looks uneven, deflate and reseat it
Sometimes the tire sits unevenly. Let the air out, massage the tire to reseat it, and try again.
Step 3: Inflate to full pressure
Check the tire sidewall for recommended PSI. Inflate to that pressure (or slightly lower if you don’t have a gauge, you can fine-tune it later).
Step 9: Reinstall the Wheel
Front Wheel:
- Slide the wheel back into the fork
- Make sure it’s centered
- Close the quick-release (should be tight)
- Reconnect the brake (if rim brakes)
- Spin the wheel, it should spin freely without rubbing
Rear Wheel:
- Pull the derailleur back to create slack in the chain
- Thread the chain onto the smallest cog
- Slide the wheel into the frame dropouts
- Make sure the wheel is seated properly (centered, axle fully in the dropouts)
- Close the quick-release or tighten the thru-axle
- Reconnect the brake (if rim brakes)
- Shift through the gears to make sure everything works
Step 10: Test Ride
Before you ride off:
- Spin both wheels, they should spin freely
- Squeeze the brakes, they should work
- Bounce the bike, nothing should rattle or fall off
Ride slowly for the first minute to make sure everything feels right.
If the bike feels normal, you’re good to go.
Common Problems and Solutions
Problem: The tire won’t go back on the rim
Solution:
- Make sure the tire isn’t inside-out
- Deflate the tube a bit (too much air makes the tire hard to install)
- Use your palms, not your fingers, to push the tire on
- Work from both sides toward the middle
Problem: The new tube goes flat immediately
Possible causes:
- You didn’t remove the debris from the tire (check again)
- You pinched the tube during installation (start over with a new tube)
- The rim tape is torn and a spoke is poking through (fix the rim tape)
Problem: The tire is bulging in one spot
Solution:
The tire isn’t seated properly. Deflate, reseat the tire, and inflate again.
Problem: I can’t get the tire off the rim
Solution:
- Make sure the tire is fully deflated
- Push the tire away from the rim on both sides to loosen it
- Use tire levers, not screwdrivers
- Some tires are just tight, keep working at it
What If You Don’t Have a Spare Tube?
Option 1: Patch the Tube Roadside
If you have a patch kit, you can patch the tube instead of replacing it.
Quick steps:
- Find the puncture (inflate the tube slightly and listen for hissing, or submerge in water and look for bubbles)
- Roughen the area around the puncture with sandpaper (included in patch kit)
- Apply glue (let it dry for a minute until tacky)
- Apply the patch and press firmly
- Wait a few minutes for it to set
- Reinstall the tube
Downside: This takes longer and isn’t always reliable. Better to patch at home.
Option 2: Use a Tire Boot (for big cuts)
If your tire has a big cut (not just a small puncture), air will push through the cut and pop the tube.
Tire boot solutions:
- Dollar bill (fold it and place it inside the tire over the cut)
- Energy bar wrapper (same idea)
- Actual tire boot (a patch designed for this about $3)
The boot reinforces the tire from the inside so the tube doesn’t bulge through the cut.
This is a temporary fix. Replace the tire when you get home.
Preventing Flats
How to Reduce Flats:
1. Check tire pressure regularly
Under-inflated tires are more likely to pinch flat or pick up debris.
2. Inspect tires for embedded debris
Pull out glass shards, thorns, etc. before they work their way through to the tube.
3. Replace worn tires
Bald tires with thin tread are more vulnerable to punctures.
4. Avoid riding in the gutter
The edge of the road collects glass, thorns, and debris. Ride a foot or two off the curb.
5. Use puncture-resistant tires
Tires with extra puncture protection (like Continental Gatorskins or Schwalbe Marathons) reduce flats significantly.
6. Consider tubeless tires
Tubeless setups use sealant that plugs small punctures automatically. More complex to set up, but fewer flats.
What to Do With the Old Tube
Option 1: Patch It at Home
Fix the puncture with a patch kit. Now you have a spare tube again.
Option 2: Recycle It
Some bike shops accept old tubes for recycling.
Option 3: Repurpose It
Old tubes make great:
- Bike tie-downs (cut into strips and use as bungie cords)
- Rim strip backup (emergency rim tape)
- Wallet (there are DIY tube wallet tutorials online)
Should You Learn This Before You Need It?
Yes.
Don’t wait until you’re stranded 10 miles from home to learn how to fix a flat.
Practice at home:
- Remove a wheel
- Take the tire off
- Remove and reinstall the tube
- Put the tire back on
- Inflate it
- Reinstall the wheel
Do this once or twice and you’ll be confident when you actually get a flat on the road.
Final Thoughts
Fixing a flat tire is a basic bike maintenance skill that every cyclist should know.
It’s not hard. It’s not complicated. It just takes practice.
First time: Might take you 30 minutes and feel frustrating.
Third time: You’ll knock it out in 15 minutes.
After a dozen flats: You’ll fix it in 10 minutes without thinking.
Carry a spare tube, tire levers, and a pump. Know how to use them. And you’ll never be stranded by a flat again.
