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.
My tubeless tire keeps going flat. The air comes out near the rim/valve as you can see here:
I have tried to tighten the valve screw and turn the wheel around so the latex would cover the inside, but without much success.... Read more >>
Top of valve looks like Shrader but is smaller (5mm).
Core unscrews easily using nut shown.
Is this an alternate Presta version valve, so if I'm using a pump / compressor with car / Shrader attachment, would I just need a Presta to Shrader adaptor? Tnx
Took a ride on my MB today on a trail. it was 88 degrees here in Texas. still. It was err... challenging. Got home and realized I lost something so I took my road bike down the same path since it was hard packed dirt. It was a breeze what a difference.
Now the MB is maybe 8lbs heavier and has dirt tires, is it mostly the tires or both extra weight and tires. I mean its only about 8lbs. Its 26X1.95 mb and 27X1.25 road tires.
Any old timers still out there to chime in. :-))... Read more >>
I pulled my bike out from a winter hiatus and got a flat on my first ride. The hole was right next to the valve. I bought two more tubes, did a change, went on a ride and got a flat in the same spot within ten minutes. I replaced it with the 2nd tube and the same thing happened within 10 minutes again, in the same spot. See photo to see where the hole is appearing. Also the 2nd photo shows how the rim strip appears to have shifted to the side. Would that be shifting and rubbing the damaged area? Are those things supposed to be glued down and not shifting? I suspected that ma... Read more >>
Will a 30, 32 or 40mm tire run OK on a 35mm rim? Both 700c
That is 700c x 30 (32 or 40) tire on a 700c 35 rim.
Is there a table to use for checking various tire/wheel compatibility?
I'm concerned about bulging one way and pinch flats if too small
Bud... Read more >>
I've had my mountain bike for 5 years and I've never had to change the tires. Past 3 months or so I've been getting more and more frequent flats, and now there is a hole straight through the top of my rear tire.
Yesterday I notices the hole, so I wanted to replace it with a new tire. What type of tires at nowadays works good in term for mountain bikes.... Read more >>
My tubes keep bursting (either deflating rapidly soon after inflation ,or after a few hours, or overnight). I inflate them to maximum pressure and they always seem to burst on the inner side, closest to the rim. So am I just getting cheap tubes or is something else doing this? The holes seem to occur on the "seam". There's nothing sharp in the tyre and no sharp edges on the rim tape. The spoke nipples aren't sticking through the tape either. I have a theory that I am inflating tubes too rapidly with my air compressor and this could be overstraining the tubes, especially when they are cold 10 C... Read more >>
Which Stan's No Tubes kit should I get to go tubeless?
My wheelset is Transition Bike Company Revolution Trail 27.5 with 32 spokes. The tires are Continental Trail Kings.
I think I want the Flow Kit but I'm not sure...
... Read more >>
That Deelite bike I saved from the crusher has 27.25 X 1.25 inch wheels on it plus fenders I was able to clean up and save the fendets. But to get the wheel on and off you have to deflate the tires to get the axel into into dropouts and reinflate. Is this common on some bikes? I have never run into it before.
Below is the $15 bike I rescued from a Thrift store and refurbished. It was missing the brakes, brake cables and brake stops.. Now it ready to roll.
Read more >>
I have a mountain bike with Mavic tubeless ready wheels. I went to change the tires and the front wheel is leaking air from the stem (see pics). A bike repair guy told me to replace the stem but it still leaks in the same spot. I cleaned the old sealant from around the stem. I shook the tire to encourage the sealant to plug the leaks and it just came oozing out. I waited overnight to see if maybe the sealant just needed some time to take hold.. still leaking.
Any ideas of what I can do to fix it?
Imgur album... Read more >>
Can someone tell me the difference between 700 x 23c slick and semi-slick tyres? I see some racing bikes with small tread and I see some with no tread at all.
Thank you... Read more >>
I have just fitted a 700 x 23c tyre to a rather wide rim with an inner width of 18mm. Can anyone tell me the possible issues I may encounter with such a combination?
Thank you... Read more >>
Hi all, long time.
I know there's a few threads about where to get best tire buys online, but I am wondering what anyone is using recently. I'd like to stay away from Amazon, preferably a place that takes PayPal. The tires I'm looking for are old style Schwinn sized, 27" 1-1/8, I think. Thanks in advance.
Steve... Read more >>
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 >>