What causes bicycle flat and repair failures? There is two types of punctures. One is a picked up road debris, a sliver of glass, tax, hair wire or a stone imbedded in the tire to leaking previous patch repair.

A cause is often old tires. Wrong tire for the rim will do it. They tend to  pinch pin holes in the inner tube. Inner tubes rely on the effectiveness of  the tire to hold in air. When you observe marks on the inner tube is a sign of an old budget tire and a wrong type for the rim giving only a few kilometers of reliability at a time. What do I mean by wrong type?

When you look at the inside edge of any bicycle rim there will either be a hook or flat edge. Correspondingly there will be a hook or flat edge in  tires rims.

If a hooked tire assembled on a flat edged rim will leak like a sieve. If a hooked rim assembled with a flat edge tire will also leak like a sieve. Hooked rims need hooked rim tires and flat edge rims need flat edged tire rims. There will be obvious hook or flat edge, a couple of size of hooks between. Some rims are hard to decide if a hook or flat rim edge.

Miss match fittings gives you endless frustration of ever softening tires. A water test in a bath tub, the whole wheel pumped up bubbles come out between the rim and tire wall showing how badly the tire is quickly leaking. It is a sign of a miss match tire for the rim.

Standard and budget tires and inner tubes are not flat proof. Old warn out ones leak like sieves and if a miss match on the rim only adds to the problem. Expensive ones cover cyclists bases made of flat resistant material. They are made clearing pins from the inner tube. In other words heavy duty flat proof specially when the right match fitting of the rims.

Cyclists can expect brand new standard and budget tires tend last several hundred kilometers or a year of trouble free service but expensive flat proof tires will  stand the test of a long time still good for many-many more kilometers than standard budget types.

Sudden and immediate flats is a sign of just picked road debris. But there are times when the tires take it's time slowly getting softer and softer a sign of miss match. leaking like a sieve caused a pinch holes or a leaking patch. Odds are high a miss match tire and rim. They are are often the cause of slow leaks.

Miss match and previous patch repair patches or a pin hole are a curse for letting cyclists down constantly.  Properly inflated tire pressures often adds pressure causing. the toped up to to go soft again within a few meters to a kilometer.

Continuing softening tire ( a sign of miss match tire and rim ) doesn't help to well because your weight disperses tire. The pressure widens pin holes and holes under patches the characteristics of slow leaks. Neglecting the right type of tire for the rim and proper inflation is often the cause of habitual puncture repairs. Running soft only hasten the life of the tire brand new tires.

You will feel a road rolling resistance in your peddling. Think of an extreme case pushing a heavily loaded wheel barrow with an almost flat tire. You can imagine the push when pumped as hard as a rock. We all feel the same with our bicycles. You will notice a vast improvement if you reassembles another tire with right match for the rim.

When you experience an instant flat examining the circumference the picked up road debris is often spotted immediately before the wheel is even removed.

They are easy to find when you turn you bike upside down resting on the seat and handle bars turning the wheel round before you remove the defending object. If it is not removed every time you inflate the picked up debris punctures another hole in the inner tube you just fixed.

If the tire takes it's time to go flat after you toped up with air and can't find any road debris in it odds are a pinch mark had finally popped into a tiny hole or a previous patch has started leaking like sieve a sign to consider investigating if you have a miss match tire and rim.

Miss match tire and rim will cause pin holes to appear anywhere,  between the inner tube and the roof of the tire or the under side of the inner tuber on the rim. The rubber strap of the rim in poor condition can do it.

Budget repair kits is often a source of a patch repair frailer. Once the glue  ( cement as it is called ) is opened. used then stored ready when needed again the cement and patches don't seem to keep. The cement doesn't seem seal the patch properly rendering patch useless.

It is a common cause of patch repair failure. Reasonably priced patchy kits covers your bases in the quality of the cement and patches. Allowing any cement to get damp during wet weather conditions often causes the cement to be contaminated with moisture to a point of  failing to stick the patch altogether.

Another failure with cement is haste. Sticking patches on wet cement will cause problems. The cement should be let dry like sticky side of taps

Old inner tubes can help shawl up budget and well worn tires for a while.  Road debris has to penetrate the thickness of the old tube protecting the main tube effectively a poor man's temporary flat proofing standard and budget tires. It works good for several more dozen kilometers. But by the end of the day the tier will soon start the habit of slowly getting soft again.

When fitting a make shift flat proof bandage one side of the tire is off the rim. Start with stuffing the old tube fingering, prodding, poking and pushing nicely flat into positing the inside roof of the tire on top and inner tube. On the udder side of the inner tube rim side is perhaps not very helpful.

Pinch holes are notorious to find. No hole can hide from an under water test. This of course requires a basin or bath tub of water. First pump up the inner tube. If you are lucky enough at a petrol station you can use the free air station to do you repairs but if on the side of the road you can only make do with your hand pump can do.

If there is no accesses to water the only option is to pump the inner tube out of the tire by hand with your hand pump as full as you can. Pin holes tend to keep the tube deflated as fast as you put air in a sign of one. Working hard it is possible you can eventually feel a column of air locating the hole.

Pinch holes are notorious for hiding very small columns. They are hard to feel. They can be so tiny it will take a lot of effort to expand the hole enough to feel a column.

Cyclists are often forced to consider if is the valve. If the valve proves OK keep at expanding the inner tube till you feel the column of gushing air. The valve should be the first thin checked.

If you have accesses to same sort of water troth  like a sink or bath tub immersing the inner tube eventually you will come across a bubbling column. Pinch holes are very tricky. They are so tiny as soon as you you remove the tube out of the water you will loose site of the hole.

It may take several attempts at re-immersing to keep track of the hole every time you dry the concerned area. You can only do the best you can. Once you have site of the tiny pin prick, with ball point pen circle it before you loose site of it again.

If there is no pin hole bubbling you would have bound to have found a previous patch leaking. It is important to wait for several seconds under water for any sign of a single bubble struggling to come out from under the patch or scan closely bubble fluff found the edge. This would apply to the valve. Bubbles resting on the surface of the tube is a dead give away the tube is leaking like a sieve.

If you fully inflate a good or brand new inner tube with a good tire and rim match checking a water test you will note no bubble fluff is an good indication of what inner tires should be. Going by that any bubble fluff is a strong indicator of a inner tube leaking a big contributor of slow leaks. Time to investigate double checking once and for all the rim and tire match.

In the case of pinch hole examine the rest of the tube for evidence of similar scuff marks that look like they are about to go into a pin hole. Theses are all the more reason to make doubly sure you have the correct rim and tire match.

With a pen circle and look for any others and circle those as well. Then you have the option of patching those before they go or at lest aware the potential flats are in the future of by a new inner tube.

Noting the position of the hole if on top or underside of the inner tube indicates if the tire or rim is causing the pinch mark problem. Again a double check incentive for tire and rim matching. That should give a clue on the next logical step covering your bases protection.

Before you  patch the tube hole deflating the tube vacuum flat helps eliminate the roundness of tube that tends, Roundness tends to lift the edges where they tend not to stick creating the edge leeks often the cause of puncture repair familiar.

In the case of the car like shredders  type valve a technique is to roll up the tube into a ball to you chest and pressing the inner core of the valve in. The pressure will insure a nice vacuum flatness.

Don't remove the silver backing of the patch just yet. Ink of pens seem to interact as a bond with cement acting as a seal. In a dry run  line the patch so the hole is right in the center and trace an outline. The resulting  template insures you can see what you're doing aiming the patch so the hole is dead centre when your ready for the cement process.

With a scrapper such as a cheese grater like scrapper provided in the repair kit or some sand paper scrap the surface of the template cleaned to a dull mat finish. Now your a ready to apply the cement.

If you're using a brand new kit, unscrew the cap. In the top is a little pin. Turn over and pierce the silver seal. Don't empty the container or you will end up purring a messy glob. Squeeze a glob right on the center of the ink circle.

Spread the rubber of the tube to widen the hole letting the cement drain into it to help plug it. Screw the cap back on the container using it to spread the wet cement covering beyond the perimeter of the template.

Don't spread a thin layer or you will have a puncture reaper failure problem the patch won't stick. Spread the past spreading a layer from the center. To help cover your bases of the edge of the patch spread outwards over the template outline. Make sure you allow the cement to dry sticky. Now you can tear off the silver backing of the patch.

It is not really necessary, but a helpful option to spread some cement on the underside and edges of the patch to insure you have covered your bases. Let both the patch and inner tube dry tacky. When sticky enough it is like sticky tape.

Eye up a line of site the center pen mark circle to the center of the patch and press on.  You will only have one shot at this because the cement will stick fast.

Watch your eye angle coordination is squaring the patch exactly to the perimeter of the template. Use a round edge of your pen smoothing round the edges. Don't Concentrate so much on the center but the edges of the patch. Now the the inner tube can be reassembled back into the tire and rim.