Discussion

While growing up in Spokane, Washington, U.S.A., I used a bicycle to get just about everywhere I needed to go. To school, to baseball practice, to work, to the store, you name it - if I needed to get there I did it on my bike. While in college I even worked for a summer designing and setting up mountain bike race courses on (big surprise) my bike. Over the years I've suffered too many flats to count. Lucky for you I wont try. The point is, I've had lots of practice with all kinds of methods for fixing a flat tire (yes I've even used duct tape; not recommended) and I've grown fond of using different methods under different circumstances.

Tube Replacement vs. Patch (To patch, or not to patch? That is the question.)

The argument over whether to patch your tube or replace it primarily comes down to 2 factors: money and time. A correctly applied patch will provide a permanent fix to your flat tire blues for less than the cost of a power bar while a new tube is going to run about $5-$12. The down side of the patch is that if you're in a race, riding at night, riding in the rain, or otherwise extremely limited for time, applying it takes a few minutes longer than simply replacing the tube. 

Another consideration is the relative weight and bulk of carrying a new tube vs. a patch kit. Tubes don't weigh much, or take up much space but by comparison a patch kit is much smaller and lighter.

When I was riding every day, I carried a spare tube in my backpack. When I'd get a flat, I'd swap out the tubes and take the bad tube home where I could take my time and patch it correctly. Then the patched tube became my new spare. If you're riding a lot, this is really a handy system that gets you the best of both worlds, economy and expediency.

Fix - a - Flat Goo

There are some products on the market that allow you to squirt glue into your tire. The aim is that the glue will coat the inside of your tire and plug the hole. I have limited experience with these products but I do have some thoughts. The goo is relatively expensive and only a temporary fix. Once you squirt it into a tire, that tire should be replaced (not patched) at your earliest opportunity. This is the least economical method of flat tire repair and creates more waste than replacing or patching. That said, I do believe that it has a place in a competetive racer's arsenal, or as a last, or fastest option.

 

Key Concepts

Tire Anatomy

Your bicycle's tires are built differently than your car's tires. Your car doesn't use tubes, which is why if you get a flat tire on your car you have to take it into a shop for repair. Your bicyle's tires have tubes in them, which is why we can fix them ourselves.

For our purposes, you need to understand that your bikes wheels consist of 3 major components: the wheel, the tube, and the tire. The wheel provides the structure, the tube provides the nice comfy ride on a variety of surfaces, and the tire protects the tube while providing traction and keeping the tube attached to the wheel. Check out this exploded illustration by Beau and Alan Daniels of Technical Illustrations at www.technical-illustrations.co.uk.

When you get a flat tire usually 1 of 2 things has occurred: either you've ridden over some foreign object (glass, a thorn, etc.) that punctured your tube, or your valve stem (the part where you fill the tire) is leaking. Luckily we can usually diagnose which has occurred because these different causes have different symptoms. If the tube goes flat immediately, there's probably a hole in it caused by some foreign object. If the tube goes flat slowly, you may have a leaky valve stem, or perhaps a foreign object has punctured your tube but is still stuck inside and is partially

Diagnosing the cause of the flat should be your primary focus in order to repair your bike's tire. Overlooking the cause of your problem can lead to worse problems. For example, during my sophomore year in college I was on my way to a 7:30 AM calculus class when I got a flat. In a hurry, I quickly removed the damaged tube, stuffed it into my book bag and replaced it with my spare. I pumped it up, jumped on, and rode about another 60 feet when the new tube went flat. You see, I didn't pay attention to what had caused the flat. I didn't notice the thorn still stuck in the tire, and when I rode off on the new tire, that thorn claimed its 2nd victim, my spare tire. With no other options and about 3 miles ahead of me, I locked up my disabled bicycle and jogged the rest of the way to class.

If your flat tire is the result of a puncture, you need to remove whatever has punctured the tire before installing a new or repaired tube. If you suspect that your Tools Required.

Tubes come with 2 options for valve stems: presta, or shrader. Presta valves are tall and skinny, whereas shrader valves are just like the ones on a car.

Shrader Valve Presta Valve

Unless you're a world class competetor, the technical advantages of one over the other are negligable. If you want a detailed technical description of the differences, go here www.sheldonbrown.com/brandt/presta-schrader.html. In my experience shrader valves are more durable and more cost effective. I almost always prefer shrader valves for the simple reasons that they can be filled at any gas station (I don't always carry a pump), and durability is my friend. The one exception is on my road bike which has very narrow rims thereby making presta valves necessary. You can convert your rims to accept shrader valves by drilling the holes a little bigger, or if you just want to be able to fill your tires at a compressor without changing to shraders, you can buy one of these little adaptors for less than 2 bucks.

It screws on right over the presta valve and presto! (pun intended) you've got yourself a shrader valve. If you suspect that your valve stem is leaking, you can fix a shrader valve but will have to replace a presta valve tube. To fix a leaking shrader valve, get yourself a shrader valve tool (see below) and tighten the core inside the valve. Remember rightie tightie, leftie loosie.

 

Tools Required

Whether you're patching your tube or replacing it entirely, you'll need a set of tire levers. These help pry the tire off the wheel, exposing the tube. These are inexpensive and WAY worth the cost. They come in different sizes, shapes, and materials, and come in sets of 2 or 3. I prefer metal ones (I've broken lots of plastic ones, remember durability is my friend) in sets of 3 like these.

Don't skimp here. Using screwdrivers, or other tools with sharp corners or edges can cause further tube damage. Trust me, tire levers pay for themselves with their 1st use.

If you're patching your tube, you'll need a patch kit. Kit components usually include patches, glue, and sandpaper or a scratchy metal disk for roughing the area to be patched. Lately I've grown fond of SKABS by Slime. SKABS are handy pre-glued bike tube patches. They cut down on carrying bulk and weight, and eliminate the need for messy glue. Truly cool!

Lastly, you'll need a pump. Now let's get on with the deed.

 

Fixing Your Bike's Flat Tire

Step 1

If you know you have a leaky valve stem, you can tighten it without removing the wheel. Insert a shrader valve stem tool (seeTools Required) into the valve and gently turn clockwise until snug. Replace your valve covers. If that doesnt solve your problems proceed to Step 2.


Step 2

Remove your wheel from the frame (back tire) or forks (front tire).

Ifyour bike uses "v brakes", you'll have to disengage the brake cable in order to remove and re-install the wheel. Do this by gently squeezing the brake arms together and removing the cable from its slot.


Step 3

Using your tire levers, remove one side of your tire from the wheel. Tire levers have a slotted end and a solid end. Begin by inserting the solid end between the wheel rim and tire. Then lever the tire out of the rim channel. Attach the slotted end of the tire lever to a spoke. This will free up your hands to proceed. Use another lever to do this again about 6 inches from the first lever. Repeat with 3rd lever, or remove the 1st lever and use it to continue the process until the tire comes off easily. Remember, you're only removing one side of the tire. You'll remove the rest after you remove the tube.


Step 4

Remove the tube. Now the rest of the tire will easily come off the wheel.


Step 5

Find the cause of the flat.Carefully and slowly run your fingers along the inside of the tire looking for any foreign objects. If you find any, remove them. If you have trouble finding the cause of your flat, pump some air into your tube and hold it under water in a sink or bath tub. The leaking air will create bubbles and show you where the hole is. Then search the tire in the area where the hole was created. If you find the culprit, good. Pull it out.

If you're replacing the tube with a new one, skip to Step 9. If you're patching, keep reading, grasshopper.


Step 6

Prepare the tube for the patch. Make sure the area around the hole (2 inches in all directions) is clean and dry. Use the sandpaper or scratchy metal disk from your kit to rough up the area. You don't need to put deep scratches in the tube. Just be sure that the entire area the patch will cover is slightly textured.


Step 7

For a glueless patch, like SKABS, proceed to Step 8.

If you're using a glued patch, smear a small amount of glue over the area where the patch will go. Don't put too much glue; use just enough to cover an area on the tube slightly larger than the patch itself. Then wait 2 or 3 minutes for the glue to semi-dry.


Step 8

Remove the paper backing from your patch and apply it to the tube. Squeeze and press it into place for a good bond; wait another minute or so. Then remove the plastic patch cover (no cover on SKABS).


Step 9

Pump just enough air into the tube to make it hold its shape.


Step 10

Put one side of the tire back onto the wheel.


Step 11

Place the valve stem into the valve hole in the wheel and feed the rest of the tube back into the tire.


Step 12

Reinstall the tire onto the wheel. When you get to the end, use your tire levers again to lever the tire into place.


Step 13

Make slight adjustments to be sure the valve stem comes straight out the hole. Do not let it remain at an angle. This can put pressure on the tube where it meets the stem, ultimately causing a future flat.


Step 14

Pump up the tire to desired pressure.


Step 15

Reinstall the wheel onto your bike. If you disengaged your brakes, be sure to reengage before you attempt to ride your bicycle

 

Conclusion

Being able to fix your own flat tire is a freedom enabling skill. It's simple and once you've learned the process, you can ride anywhere without fear of getting stuck. Believe it or not, most of the projects I write about at Project Sleuth are just as simple. Even though most projects require tools and the competency to use them, they can be broken down to a simple process of linked steps. If this article was helpful to you, check out my other articles and tell your friends and family about the Project Sleuth. If you have questions, comments, or suggestions e-mail The Sleuth at info@projectsleuth.com. Cheers!

Back to Top