7. How to Fix a Flat Tire
How to use a patch kit to repair a tube. Also demonstrates how to remove and install a tire.
Fixing a flat tire is one of the most common bicycle repairs. I personally recommend replacing a tube when you get a leak, but that is not always possible. If done properly, a patch will work just fine. Here’s how it’s done.
With the wheel removed from your bike, inspect the outer surface of the tire to make sure there are no sharp objects like a thumb-tack or thorn stuck in the tread.
Remove the valve cap and fully deflate the tube by depressing the valve stem with the hooked end of your tire lever. There are two main types of valve stems, a schrader valve and a presta valve. This tutorial is based on a schrader valve, but I will be covering the different valve types in another tutorial.
Now it’s time to remove your tire, one side at a time. Choose a section of tire that is away from the valve and hook one of the tire levers under the bead, directly in line with one of your spokes. Pry one side of the tire bead over the edge of the rim, and then hook the end of the tire lever to the nearest spoke. Insert another tire lever two spokes away from the first, and a third another two spokes away. Now the middle lever should fall out, and you can continue the process. When the tire is loose enough you can just run a tire lever around the rest of the rim to pull the whole side over.
After you have removed one side of the tire, the other side should come off very easily.
Now remove the tube from the tire, and try to keep track of where it was positioned in relation to the tire. Inflate the tube to approximately twice its original size. This will expand the hole making it easier to find.
Listen carefully to the entire circumference of the tube; you should hear a hissing sound that will indicate where the leak is. As a last resort you can submerge the tube in water and watch for bubbles, but you’ll want to avoid doing this as you’ll need the tube to be completely dry in order for the patch glue to work.
Once you’ve found the leak, take note of whether it is on the inner or outer side of the tube.
If the hole was on the outer side of the tube, inspect the inner surface of the tire in that spot to make sure the object that caused the puncture is not still stuck in the tire. Double check the entire inner side of the tire by running your fingers along the entire surface, feeling for obstacles along the way.
If the hole was on the inner side of the tube, inspect your entire rim to make sure there are no sharp burrs in the metal, and that the rim tape is properly protecting the tube from your spoke ends.
Now that the rim and tire are clear, it’s time to patch the tube. Select an appropriate sized patch for the hole. Use the sandpaper or scraper provided in your kit to buff the surface of the tube for an area a bit larger than the patch. You need to buff the tube so that it is no longer shiny. If the molding line is running along the area where the patch is to be applied, you must sand it down completely, or it will provide an air channel. Once buffed, avoid touching that area with your fingers.
Apply a dab of rubber cement, and then spread it into a thin coat, using your cleanest finger. Work quickly. You want a thin, smooth coat of cement; if you keep fiddling with it as it begins to dry, you’ll risk making it lumpy. The thinner the cement, the faster it will dry. It is very important to allow the cement to dry completely.
Peel the foil from the patch and press the patch onto the tube firmly, squeezing the patch tightly onto the tube.
Now inflate the tube so it is round and place it evenly into the tire. The first bead of the tire should fit easily onto the rim. Make sure you line up the valve stem with the rim’s valve hole.
Carefully fit the valve through the hole and place the cap on to keep it from falling out again.
The outer bead is harder to install, although most tires can be re-installed by hand. Staring at the valve, work the bead onto the rim using both of your thumbs.
You should never use tools to install the tire, but very tight tires may need some help. Kool Stop makes a great tool called a bead jack, which helps to pull the tire bead over the rim.
Once the tire is seated, inspect the outer edge on both sides to make sure it sits evenly all the way around, and push the valve down into the tire to make sure it didn’t get caught between the tire bead and rim.
Inflate the tire to the recommended pressure, which should be written on the side. Make sure to inspect the tire a few times while you are inflating, to make sure the tire remains seated properly and doesn’t start to bulge anywhere.
Once the tire is fully inflated, install the valve cap and put the wheel back on your bike.
I recently bought a road bike, and on my first ride, the tube on my rear wheel unfortunately got punctured. I used a cement patch kit and the tube seems to inflate well, but whenever i put it back in the wheel and start riding, the tire goes flat again. I'll take the tube out of the wheel again, but the tube seems to work perfectly. Also, when I do inflate the tire and spin the wheel, it is a bit uneven, not side to side, but up and down. My rim and tire seem perfectly fine though. Any suggestions on how to fix the problem, or what's wrong?
Thanks!... Read more >>
I've got an old road bike with 27" wheels and 27 1 1/4 (32 x 630) tyres. I just ordered some spare inner tubes online and found out that 700 28-35c should be appropriate for my bike. They have sent me 700 25-28c tubes instead though, claiming that they should still fit, as they cover all tyres from 25-38c (instead of 28, as it says on the label), which is a much broader range than the one they'd originally listed.
I've been trying to find out for quite some time now if these tubes should indeed be fine, so if anyone here has any idea about their suitability that w... Read more >>
This post may not be clear without pictures, but I'll continue...
Today I rode my bike and my valve stem on my rear tire was crooked. I went to a local gas station that has a free air compressor. I tried to move the tire back into position so the stem would be straight. No go.
I ended up taking the tire off and the tube out and putting the tube back in and re-mounting the tire. When I inflate the tube, I noticed little "cracks" in t... Read more >>
Went tubeless on the Lefty last night. seems to be working and holding air but I have a slight wobble that I don't think was there before. Should I let the air out and try to reseat the tire or what. Seems to be seated ok.
Bill... Read more >>
I'm having trouble inflating the tire on my Dutch bike (I now live in the UK, no longer NL, by the way). It's got what I'm pretty sure is a spring-loaded or one-way Dunlop valve. As you can imagine since the valve is on my desk, the tube is now deflated.
The problem, I think, is that I can't get the valve to open. I'm using a reasonably potent two-cylinder pedal pump, but I can't seem to force air through the valve. When everything is seated properly to pump the tire, if I contort myself to hold the nozzle of the pump as tightly against the adap... Read more >>
While removing the pump head after pumping, the presta valve got broken. I then reinserted the pump to check whether it can sill be pumped, and all of a sudden the remaining needle is lost ( might have gone inside the tube). Is there any way to fix it without changing the whole tube?
And if I need to change the tube, then what would be the tube size? My bike is Giant OCR3 2009 model.
... Read more >>
When I was younger, I only had a bike till I was25. I am trying to get back into biking again. I bought a vilano performance hybrid roadbike and it came with 700 x 28c tires with presta valves. Now, its been a long time, but what was wrong with schreider valves ? Anyway, I know tubes loose air pressure over time, but I only rode the bike In the parking lot once to see how the adjustments were, one week later, I went to ride the bike, and both tires were completely empty, I pumped them back up to 85 psi, and a week later they were completely empty, I tightened the nuts after and rep... Read more >>
Hi all. I have a 1993 Nishiki Modulus I use to commute to university classes, except right now I have a flat in the back tire. The tube on the back tire says its size is 27"x1" 90-110 psi, but all the tubes I can find online are x1 1/8" or x1 1/4". Am I missing something about road bike widths here? Will that extra eighth or quarter of an inch mean the tube won't fit, or can I get by with it? If not, where can I find a tube to fit my rim?
Apologies if this question has been answered previously, I only had a quick look around before I asked.
D... Read more >>
When I change the tube on my bike (it's s Dawes Super Galaxy). When. I pump up the tube it pushes the tyre out of the rim. Happened 4-5 times yesterday. Lost a brand new tube.
Does this mean the tyre is knackered?
Thanks in advance.... Read more >>
I have a Specialized Rockhopper with Maxxis High Roller 26x2.35 tyres. I've only just noticed lots of short diagonal splits (almost like knife nicks) on the rear tyre. They seem to be in line wth constructional lines within the tyre. I know I've done some riding with the tyre slightly under-inflated but is there any connection ?. Has anyone experienced similar wear and do you think its safe to ride on ?..Many thanks for any replies... Read more >>
I'm looking to order a new front rim online to save a few bucks but it's a little difficult to choose the correct size. Ideally, I'd like to order the same size rim, or at least one for which I can still use the old tube and tire.
Rim size: 622 x 17
Tire: 700 x 35c
From my research online, I know 622mm is a standard/common rim size, and 17mm is the inner width of the rim. For the tire, the x35 refers to the size of the tire when fully inflated. Is this correct?? Also, from Read more >>
I am trying to fix up a bicycle for my nephew The tires on it are dry rotten, but read 26x1.50, I went to the store to buy these, but they only had 26x1.75, which I bought 2, along with 2 1.70 tubes. Will these work on the bike rims? I have been the route on the charts, but didn't understand, would greatly appreciate a yes or no answer!! Thanks!!... Read more >>
I live on a bicycle and I used to get flats all the time because of poor road conditions and high tire loads. Fixing a flat is time consuming because I have to remove loaded front and rear bike racks with milk crates loaded with gear and homemade panniers.
I tried Slime, I tried thicker inner tubes, I tried homemade liners. Then one day I put an old 27" worn out old school road bike tire inside my 28"/700c x38 cross tire. It fit perfect after I cut the steel bead away with a scissors.
I reassembled the tire on the rim with no difficulty, partially inflated the tube to... Read more >>
The rim width of my 700c wheels is 25mm. I am therefore assuming these are hybrid wheels and require thicker tyres. Can anyone advise me whats the thinnest tyres I can fit onto my wheels?
Ibie... Read more >>
I took my bike to a shop to get a replacement rear tire. (Old well maintained Centurion LeMans 12-speed) The shop took the tire off, swapped the tire and tube, and put everything back. I know that they lubricated the chain because it was greasy when I checked it. But when I pedaled home, it made a clacking noise. Seemed to be related to pedaling, not so much when I was coasting, more clacking at higher speed. I couldn't put it in the lowest gear. When I got home, I removed the saddle bags and slipped the quick release wheel out of the forks (just an inch or so) then replaced it. Seemed... Read more >>