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.
Recently I have been looking for a narrower ETRTO 590 tire. In the USA, I wasn't able to find anything except 37/38 wide. I wanted something a bit narrower, and still have relatively high pressure capability. I have been using 90 psi Kenda 37-590 tires.
I ordered Schwalbe 25-590 wheel chair tire and tube - a bit skinnier than what I want, and 85 psi MIN, 145 psi MAX. I may still try it out on the front of my Miyata 310.
More recently, I found that in Europe, Schwalbe offers a 28/32-590 rated at 85 psi - just what I was looking for. Schwalbe USA said "...we don’t m... Read more >>
I learned a lesson today about tires. I went to get road tires for my Trek 831 MT Track.
You cannot just take a 26x2.10 tire and swap it for a
26x13/8 tire. The inside diameter is about a inch different. Is there a simple answer to this? or do I need to alter my plan.... Read more >>
I have a mountain bike - 26" and the tires are 1.95
I also have a cruiser bike - 26" and the tires are 2.125
It seems I can use the same innter tubes for both bikes because I get the ones that are like 1.9 to 2.1 or something. I keep the tires on both bikes at 55 psi which is basicly the middle of the range it says to inflate them to on the tires. After 2 weeks they are down to about 48 psi or so.
I ride both bikes daily and for about 20-40 min each.
When I ordered new tires for the beach cruiser I bought 1.125 and I just realized the oth... Read more >>
I got this 21 speed mongeese from a friend of mine that tire that shaky tried everything I know and it's still shakey what do I do I will put a pic on it and the second... Read more >>
How should I store the spare tube/patch kit/tools for my bike in case I get a flat while riding? A backpack won't work as it is too heavy and inconvenient. I was thinking about making a small bag to attach to the frame to store the tube/kit and wrench in, but I think it may mess with the way the frame pump mounts to the frame.
BTW, should I take a spare tube or a patch kit? I understand there are some times where a spare tube is the only way (i.e. blowout, giant rip in the tube, or the valve stem comes off) but a wrench (needed to take the rim off the bike) adds weight (although t... Read more >>
I ride a hybrid with 700x38c tires . After getting a few thousand miles from the original tires , the rear one was getting very worn so I decided to replace it .
Ordered a replacement from Amazon a few weeks ago , but instead of sending a 700x38c , they sent me a 700x35c . Wanting to keep the front and rear tires the same size , I returned the 35c and again ordered a 38c . Today , the new tire arrived and again they sent me a 700x35c !!!!!!!
My questions are .... (1) will the 35c fit properly on the original rim that came supplied with the 700x38c tire and .... (2) ... Read more >>
I want to create a "tire-repair kit" for next summer. I'd like to ride on the Katy (MKT) trail that runs through town but I don't want to have a repeat of what happened a couple summers ago, so I'd like to create a tire-repair kit.
A couple summers ago I was riding along on the trail, and was a good ten miles from home, when I heard a "psst..." coming out of my rear tire. Within about 30 seconds the tire was completely flat. It was pretty late at that point in the summer day (6:30 or so) so I had to ride my bike on the rocky terrain, on a flat tire, about 10 miles back home. (I di... Read more >>
Before I continue I must clear this topic up by saying that I'm only posting this for curiosity sake. I'll admit it... they're really dumb questions, but I had to ask them:
My first question is: would it be okay to temporarily run 26x1.95 inner tubes in a 27x1 1/4 tire at low pressures? My concern would be that the expanding tube would "force" the tire right off the rim, but am I right?
My second (and more "intelligent") question is: if you don't have a tire (but need to use your bike), could you inflate the tube (enough to give it shape), wrap the tube duct-tape to h... Read more >>
I'm plagued at the moment by tubes which keep bursting on the side closest to the rim. There doesn't seem to be anything obvious which is doing this such as spoke heads sticking out through rim tape, grit, thorns or other stuff stuck to the rim. I inflate tubes to the max recommended pressure (65 psi) and this hasn't happened too often before, so the chances are that the tubes are bad quality (even though they are weighty and not cheap).
I've found that patching holes on the inner side of a tube doesn't work too often because the tube has to stretch and deform as it pushes into t... Read more >>
I understand cheaper regular tyres are made with a steel wire bead. But are all folding tyres made of Kevlar bead? I have just purchased a set of tyres as per attached photo and wanted to know if the bead is Kevlar. Can anybody please help?
Thanks... Read more >>
Earlier this year I replaced tires on both vintage bikes, due to dry rot... Age (30+ Years).....
I didn't think anything about the procedure, and did the following on first time inflation (I have an air compressor in garage):
Put about 20 Pounds of air in, then bleed it out.... Then do 30, and bleed...
Then 45, and bleed...... then went to 70....
I used to do the same (at lower pressures) for motorcycles.. I was told this prevents the inner tube from twisting and pinching in the tires.
Is this acceptable for bicycles, too? Or is ther... Read more >>
My rear tire went flat overnight and when I inflated it in the morning, a bulge formed (see photos). I removed the tire and found a slightly worn spot about the size of a dime on the inside of the tire where the bulge was. I couldn't find any debris in the tire. The tube itself is not worn in that spot.
I remounted the tire twice and the bulge formed in the same place each time. I tried inserting a folded dollar bill, but it didn't help.
The tire is about 2 years old, but hasn't had much use (just occasional city riding). The tube is about a week old.
Ha... Read more >>
Noticed this today... trying to figure out what I ran over to do this?
Can I still ride?...
Anything to do to repair?...
or is it replacement time?
Thanks!... Read more >>
The current Continental tire and tube chart has two columns designated ca. and PU. What do these designations mean?... Read more >>
Please forgive me if this has been covered somewhere on this site, if it has, I can't find it.
I have 26 x 1.50 rims with 26 x 1.75 tires
needed two new inner tubes.
The bike shop sells me a 26 x 1.50/1.75 with Schrader valve and a 26 x 1.9/2.125 also with Schrader valve.
They didn't have anymore of the 1.50/1.75 with Schrader valve and said the 1.9/2.125 would fit especially since it's a mountain/city bike.
The problem is that the 26 x 1.9/2.2.125 is too "big" for the wheel.
The width seems OK but when I put the tube on the rim t... Read more >>