Bicycle inner tubes.

[Captain Dirty]

As you have discovered there are 2 types of valves in common use on bicycles today. The Schraeder valve is the larger one (a little over 0.3" in diameter) found in automotive use and on older, cheaper, and more utilitarian bicycles. The Presta valve is narrower (about 0.2" in diameter) and is common on newer, dearer, and more "serious" bicycles. While the Schraeder is held closed by a spring that may be opened by pressing central pin, the Presta must be opened or shut by turning a knurled nut on a central pin. The two are not compatible although most good floor (home) pumps have a combination chuck, most frame or mini (carry on the bike) pumps can be set up for one or the other, and most CO2 cartridge inflators are Presta only. There are screw-on adapters that allow one type of pump to inflate the other type of tube; these are about the size of and as easy to lose as Schraeder valve caps. There are also grommets that reduce Schrader sized rim holes to Presta size to prevent the smaller stem from moving in the hole and causing the tube to fail.

The most common and expedient method of dealing with a flat on the road is to replace the old tube with a new one after checking for and resolving any obvious cause. Obviously you or a companion must be carrying a spare tube and a pump or other means of inflation. If you cannot make the repair or there is some urgency such as a time commitment later that day, the next method is a cell phone call for a lift. Depending upon the likelihood of an incident and the consequences of not having tools and spares you have to decide what to carry.

Once home I throw the flat tube into a box of tubes to be repaired and take a sound tube from a box of new/repaired tubes to put on the bike. When I have 5 or 6 tubes that need repair I will repair them. Bike shops sell repair kits that generally include a few patches, a scraper or bit of sandpaper, and a tube of rubber cement. Be warned, the tube of cement is good for one use. Once opened the cement hardens and will be unusable the next time you need it. Save the tube for emergency use. I buy an 8 oz, "brush in screw cap" can of cold vulcanizing cement from an auto parts store, Walmart, or Amazon. It lasts about 5 years before enough volatiles have evaporated to make its use questionable.

Most of the rest of my "home" tube repair kit is assembled from "Rema Tip-Top" brand components available through bicycle shops or on the internet. Rema items include 100 piece box of size F0 patches (5/8" diameter for 23-25 mm racing tubes), another box of Size F1 patches (1" diameter for larger bike tubes), a box of Size F2 patches (1"x2" oval for wheelbarrow, lawnmower, etc. tubes), and a 1 qt can of buffing fluid (now about 20 years old and half used). Other items include a brass bristle brush, a "stitcher" (a serrated edged roller), and a floor pump.

The home repair drill is a follows: 1. Find and mark the leak. Some small leaks are so slow that under water they release a tiny bubble a second as opposed to a stream of bubbles. I will usually enlarge the leak with an awl so that the hole will "telegraph" through the cement. 2. Buff the area with buffing fluid and the brass bristle brush. This will usually remove the chalk or ink that I marked the hole with, hence the use of the awl. 3. Apply the cement and wait, usually at least 15 minutes, sometimes I have forgotten for an hour or more. 4. Place the patch and stitch it down. 5. Wait, typically overnight to ensure the cement cured. 6. Pump up the tube to see that it holds air (typically overnight). 7. Deflate the tube, put a cap on it so the center pin (Presta) or edge of the stem (Schraeder) will not wear a hole owing to vibration while being carried on the bike, and roll the tube securing it with a rubber band. 8. Put the repaired tube in the box of sound tubes. Five or more tubes at a time is more efficient that one or two at a time.

 

[Captain Dirty]

Turn tire inside out and use microfiber cloth to lightly drag across the inside of the tire(now facing out). I have had trouble finding small pieces of tire wire stuck in the bike tire with fingers. You can also put mark on tire at valve stem then find leak in tube to help search for cause of flat.

A bit of the arcane: "Good" practice is to mount a tire so that the name is centered on the valve stem hole. Thus the tire is "marked" and the "wound" in the tire should correlate with the leak in the tube going in one direction or the other.

 

[Unclewillie]

So I have a Trek bicycle that is about 15 years old. The rear tire went bad but still held air. I got a new tire, put it on, but the old tube leaked. Took it to a bike shop and had a new tire put on the front and a new tube in the rear. The both leaked. Long story short the rear wheel had a sharp edge where the valve stem was the I dremeled down. I went through a total of 5 tubes in the back and three in the front and the bike shop did the last 2 that finally held air.

The spoke guards were good. I used baby powder inside the tires and tubes to help the seat. I used my hands to seat the tires without tools. 15 years and no flats then all the sudden I can’t get them to hold air. I’m assuming I was somehow pinching tubes?? Tubes are cheaper than they used to be?? Any ideas?

Should be a rubber strap / band with a valve stem hole that goes on first before tube or tire that's what's suppose to keep the spoke head screws from cutting or rubbing into the tube, most of the time on old wheels they will rot and fall out when the tire and tube is removed. If they are not there you can make one from the damaged tubes, simply over lap and glue but don't forget to cut out the valve stem hole.

 

[dougtrr2]

I just got back into riding and had my share of flats. Mounting the tire with the label at the valve stem so you can correlate leaks is good and something I just learned. My last flat was caused by a SMALL piece of gravel shaped like an arrowhead. You could just barely detect it on the inside of the tire. No sharp edge protruding, just sort of a dimple on the inside. On the outside you had to flex the tire to see it. It took a pair of pliers to pull it out. A close inspection is paramount, a cursory inspection would have missed it.

Doug in SW IA
(over 1,000 miles logged on the Wabash Trace this year)

 

[Alien]

When our kids were little we were living in Kalgoorlie. There were little burrs everywhere and the kids kept getting punctures all the time until I fitted puncture proof tubes. Years later I used to split old tubes and fit them over the new ones which stopped the burrs going through far enough to cause problems. A bit tricky to fit but it worked well.

 

[Jim Shooz]

I carry a selection of self adhesive patches and use them when out riding. And a spare tube for my 29" rim. I usually ride 'tail end charlie' for the groups and I reckon that I carry enough tools to change the wheels on a 747.
The problem is finding water to trace the leak. One of the group had a puncture and I tried my first trick of putting air in the tyre and moving the tyre around very close to my lips. No joy. Then I saw this drinking fountain. covered the drain hole with strips of electricians adhesive tape, waited while the bowl filled and then fed the tube 2 inches at a time through the water. Found the hole and looking around for the patches and realised; we'd been cycling around the harbour and not 50 feet away from us was a small jetty, and the tide was in. !!
Sometimes the first idea is not the best idea.

 

[ArlyA]

Gee, we have a few cyclist's here.

 

[Grumpycat]

When our kids were little we were living in Kalgoorlie. There were little burrs everywhere and the kids kept getting punctures all the time until I fitted puncture proof tubes. Years later I used to split old tubes and fit them over the new ones which stopped the burrs going through far enough to cause problems. A bit tricky to fit but it worked well.

Have done same on off-road motorcycles.

 

[ericm979]

I also learned there is a different valve now called a Presta, which I don’t want.

Presta valves are superior to Schrader, but you need to use rims made for them.

I raced bikes for many years. For a long time I was putting in 8-10k miles a year with close to a million feet of climbing. I've changed hundreds of bike tires. When I get a flat I examine the tube to see where the holes are. Sometimes I have to pump the tube up and listen or feel for the air escaping. The location and pattern of the tube punctures can tell you a lot. I always mount the tires with the biggest label at the valve, facing the left side of the bike. That way if I find a tiny hole say 12" down the tube from the valve, I only have to inspect two spots on the tire (since I don't keep track of the tube's orientation). This can be really helpful when the puncture is tiny, like from a sliver of glass a few mm long.

Those slivers can stick in the tread and slowly wear the tube so it flats 100-200 miles later. You can feel for them but sometimes they stay in the tread and don't stick out far enough. Pinching the tread together can open the tiny cut on the outside so you can see it. Sometimes you can do the opposite from the inside and see it there.

While I usually can mount tires with just my hands, sometimes that's not enough. To avoid pinching the tube with a tire lever I use the lever to stuff the tire up into the rim and away from the lever. When you're getting to the last bit of tire where it's hard to get on, go around the wheel and squeeze the tire beads into the center of the rim again. That's where the diameter is least and that gives you the most slack for mounting.

 

[ericm979]

Another tip is next time you get a Tyvek envelope from USPS, cut it into strips about 1" wide and 3-4" long and put a few in your seat bag. When you slice a tire you can put one of these "boots" between the tube and tire so the tube does not bulge out and get pinched. Being Tyvek they weigh nothing. I used one for a friend when he sliced a tire near the start of a century ride. We finished the ride on it without any problems. More durable but bulkier boots can be made from worn out racing tires.