A common frustration a tire that keeps going down even after a puncture reaper. Where do we start fixing the problem once and for all specially when there no evidence of anything embedded in the tire? Pieces of glass to tiny hair wires can hide themselves deeply embedded in the inside of the tire where most of us tend to over look to look in still in the tire not long before flat again with another hole.
Other issues if in the habit of swapping spare tires from donor spare wheels there is always the chance of swapping a different width either to wide or two narrow for the original rim width. Another tricky problem can be in the patchy repair kit itself in the cement not bonding the patch. Even pumps can sometimes give the illusion of a failed repair job. It is often discovered it was the pump all along until to late after throwing away a perfectly good inner tube.
Opening a patchy kit container you'll find a scraper virtually a cheese grater piece of tin. Specially cheep kits, they are a rather disappointing small supply of patches, for the money including a bonding cement and a piece of rubber tubing helpful in fixing some valve leaks. It is in the cheeps kits that cements tend to let you down.
Some high priced kits seem marginally better quality for the price. But the important part the cement is of a very high quality. Note. The advent of technology kits are starting to come with self adhesive patches now which explains why no bonding cement is not found in some kits. Many of us are falsely lead to believe by a half truth the glue is to be set on fire because some kits from the past required this kind of treatment. But not these days.
Theses who have done this sort of thing hundreds and thousands of times before can get themselves home. They are not fooled by those hidden pieces embedded in the tire. Experience tells them if they don't find the offending instantly "Some of these things can really hide themselves" scrutinizing carefully every centimeter inside the tire specifically looking for the hidden object as if they "know" it's there "Somewhere." as if because they'd spotted it a moment ago but lost it attitude.
A cause of puncture repair failure is the mistake of too heavy scratching cleaning the surface of the inner tube preparation damages the inner tube where patches don't hold made worse by a cheep patchy kit. No matter how new it's beyond reaper. Cheep patchy kit cements can often be the cause of repair failure. The tube left laying round in a kit or carrying bag that has gotten damp in the winter months won't help.
Experience tells us a sign of both over done preparation or a budget kit cement, on previous patches. We can be very smart in getting ourselves home with only what we have. A sign of a bad cement is recognized when patches peal off just like that. On a fresh hole you can get away without any preparation. If it a patch has let go it is a sure bet you can peal it away. Provided the tube isn't damaged by any harsh previous preparation you can redo with a brand new cement and patch.
The procedure is a last resort in a emergency or got to getting yourself home. You'll be grateful a good condition cement that holds fast even under tight pressure for ever giving you no more patch problems. If the cement is good and if you're lucky you can perhaps salvage a previous inner tube you meant to out.
A sign of gone off cement patches peel off so easily. Once removed replace with a another patch and let dry like sticky tape. For good measure apply a second coating letting that dry like sticky tap and try your luck with another patch. Under the circumstances with a bad cement three coatings all told keeping your fingers crossed.
The wise choice I think in the preparation tools is to toss away the crude scraper and replace with a nail file or a piece fine sand paper. ( Better known as emery paper sometimes supplied as a alternative in some kits ). The trick is to gently clean and sand the area round the hole to a smooth and even finish without over doing it to avoid damage to the tube. How ever it is suppressing how successful a repair was without any preparation. If the pump is working fine we can tell when something is wrong when operating the pump getting no where fast. However with pumps there bear can be some deceptions.
Fast pumps in a dozen strokes the tire comes up fairly quickly. These pumps push in large volumes of air at a time. Then there are those slow pumps that seem to take for ever for the tire to just to be soft. Experience will recognize at lest it's working. Inexperience can't help thinking there is a puncture repair familiar coming A good slow one will eventually inflate the tire to the recommended tire pressure. Sometimes with these slow ones we feel like dumping them for a faster one.
If you are using a service station pump you can often get the same problem. Probably the motorist or two before you was suppressed how difficult it was to add air to their tire, even deflating it on them. Don't let the that fool you of a paternal air leek before you are sure it wasn't the fault of the pump nozzle letting air out flatting your tire.
One good test is to watch the measure gage why the motorists before eventually realize the the service station pump needs attending too.
Never the less we can all tell "a good pump and satisfied fixed flat" when the tire inflates well and hard and stays that way hard for ever. Operating on what it should be principle with a fast pump if it doesn't it should be recognized you're headed for a problem when getting no where fast cased by a bad patch or sometimes even if the pump itself may be an illusion of a puncture repairer failure not putting in the air. Never the less watch those slow pump characteristics don't fool you on that.
Pumps available from bicycle stores come in the typical stick to mini compacts. Watch any locking lever arrangements locking onto the valve is used the right direction. Make sure you are clear on what is up, down, in or out is the correct pumping to unlocking position. If the wrong direction w ill you will have pumping problems.
If have a renewed fast pump problem a simple double checking test on another wheel will soon confirm things. Hose type pumps connectors are subject twisting and back and forth forces as we pump damaging the connector pinches holes in the rubber where there are air leaks. The latter takes it's toll on the connector. Bicycle pumps are designed for bicycle tire pressures as high as a 120 pounds per inch.
Cheep foot pumps are designed as general purpose light duty inflating footballs to motor vehicle pressures. They tend to be fast which are a maximum of 30 pounds per inch ( PSI ) where a "minimum" for a bicycle is at lest double that. Moderately priced foot pumps are the best quality and tend to be very fast and control insurance they don't let you down. For the hose stick type nothing but a new replacement connector of a good bicycle or foot or a pump of any sort wont solve that problem.
Checking down the screw cap of a hose connector we observe what looks like a cross. This cross is an important part. If it looks damaged or missing the hose won't work. If the pump and connector is good, and still getting nowhere fast can be a sign of a bad preparation of a patch letting go. As said before no leak can hide from a under water test so testing patches under water will determine if that. This is often due to the cement letting go and sometimes that obvious cause can be deceptive.
It pays to get into the habit without thinking before you remove the inner tube automatically marking the position of the valve on the side of the tire wall in case you may need it.
Pieces of glass can hide in the tire. By all means if the patch can come off replace it smartly with a new one. Then double check the inner tube by inflating it full as you can outside the tire to expand any holes other hidden holes. If you find one then you can use the mark on the tire wall lining up the valve so so the hole you found will mark the position of the offending object.
Examine the inside of the tire thoroughly as if you know it's there because you had just seen it and lost it looking for it again. Be careful with a poker poking out the fragments.
Checking over previous patches you'll often observe bulging distortions in the inner tube caused by good and tight patches due to good cement. Watch if any patch that can be pealed off the tube the inner tube is a dead give away of damage by the over preparation can never be used again.
Over preparation damage forces us to buy brand new inner tube which leads us to a third cause constantly developing new holes. As soon as we fix one flat we find ourselves finding and patching another pin hole. It's not long before the tire is flat again.
When we check the inner tube again we find another pin hole.
Then it's not long before we find another patching that before we find ourselves finding and patching another.
Most by then give up buying a new tube. Odds are the patch was successful and the tube a good one the brand new one will be punctured by an overlooked embedded object still in the tire. Sometimes we are frustrated all we got struggling with a inner tube that we'll collect a lot of patches on it and run out of cement and patches. I said it a couple of times already and I'll say it again "no air leak can hide from an under water test" including patches. The cause is a worn out inner tube often referred to as perished but often as not an over looked piece of glass hidden embedded in the tire.
With out the water test repair failures can exasperate us finding no evidence of any puncture to the inner tube we can turn to the valve. The water test is a sure thing it's is or not the valve. Bicycle valves seem to come only as one abundant car type called Schrader. However on rare accessions we can encounter a high pressure road racing valve valve tube called Presta and the English woods ( or Dunlop type ). Schrader, Presta and woods.
The under water test can show bubbles rising from inside the valve or the rubber cover and base of Schrader valves caused by the chaffing of the rim valve hole allowing to much movement cutting up the rubber shown by the bubbling. Trying to patch a Schrader round here from experience you'll find they are always a puncture reaper failure at best.
Another sources can be traced to, using no cap allowing dirt and wet weather get in potentially damaging the core mechanism. The common Schrader used in bicycles are just like car valves. Not many cyclists realize the core of a common Schrader valve is interchangeable in size with motor vehicle valve even the core of big rigs will fit a bicycle Schrader.
However different tire pressures is the issue. Motor vehicles are no more than 30 Pounds per Square Inch maximum where a minimum is at lest double that bicycle tiers a bit on the soft side. The different tire pressures is a conflict if you're thinking of using a motor vehicle tire repair store for your spare inner cores. Motor vehicle cores should only be used in emergency. If someone knew to this using a motor vehicle core replacement often explains the valve core was leaking. With a small flat head screw driver the core can be removed for inspection.
Unfortunately as most cycle shops are unhelpful with tricky leaky problems some sales personal don't even know you can remove the core.
You just have to persevere with finding a shop you can find or savage a core from old perished and damaged Schrader tubes. Alternatively visiting motor vehicle tire outfits being well aware of the different tire pressures on the cores than your bike.
As for woods the air seal is either a long rubber sleeve called ( mush ee gue moo ) "mushi gomu" or just a rubber seal. Unscrew the v valve cap, and pull out the core and inspect the seal condition. If the Mushi gomu is missing you need to replace with a new one either from the your patchy kit or a suitable piece of rubber. As metal to metal doesn't make water tight seal let a lone air tight, check any seals. This is where the little peace of rubber tubing supplied with kits comes in handy at fixing woods cores.
Unfortunately again most bicycle shops are extremely unhelpful with woods valves.
If they seem evasive they my know nothing about them or would be quick to help let a lone stocking spare cores. Nothing but the long rubber tube supplied in the patchy kit replacing the original Gushi mu won't put right. It's suppressing how hardware shops and home centers can be more helpful than bicycle shops in this area with a piece of rubber tubing that will do the job.
Prestas are another type of bicycle valve that are designed for completion road racing that are meant for pressures up to a 130psi. These tend to leak when the screw pin is bent.
All is not lost if the pump f fitting doesn't fit.
There are screw on adapters available at bicycle shops that will convert the valve to the pump fittings you'll find included in the free accessories when when buy a new foot pump. Pity there is no pump fitting to valve as adaptors. Fixing a puncture on the road side without access to a under water test is a very tricky.
Simple nail or a piece of glass puncture can be found quickly and easily making a simple and a effective puncture repair job. If the inner tube is removed pumping up really fat we can quickly find a column of gushing air marking the hole. If you fix a flat at a service station you can use the power of the free air can help quickly locate the embedded object as hand pumps are not often powerful enough.
If you are at a gas station using the a free air pump turn the bike upside down resting on the seat and handle bars. Inflate the tire while the wheel is still on the bike until air rushing out where ever the embedded object is stuck in the tire locating it for you.
All that is left to do is to mark the column of air on the tire.
Before you remove the wheel I don't need to remind you with a sharp poker to be careful when poking out the embedded object. Otherwise embedded objects are easy to find by scanning the entire circumference of the tire .It is often frustrating when there is no evidence of an embedded object. It's a pity the the good old bath tub can't come to the rescue to find the hidden leak in the inner tube on the road side. The problem of not being able to find the embedded object is caused by removing the inner tube leaving the tire hall f on the rim.
This can be a mistake for this method will not find that illusive embedded object you can't find. Instead of leaving the tire on the rim, remove the whole tire with the inner tube still in it. Before you take out the inner tube mark on the tire wall a clear mark to insure you don't loose it marking the position of the valve. Now you can remove the inner tube.
Once the inner tube is removed the only thing you can do on the road side is to inflate full as you can in the hope you can encourage expanding the hole to feel a column of air by hand. At this point circle the hole with a pen. To help prevent the ink from contaminating the cement keep the ink to a minimum circle yet clear enough you don't loose it.
Now place the inflated inner tub on the tire lining up the valve to the pen mark on the tire wall. The hole you marked on the inner tube will locate the position of what pricked the hole in it. Look carefully inside the tire. If you don't find the offending object flip the inner tube over and try the opposite side of the valve. Some of theses things can hide in the tire.
Pearl back the inside of the tire inside out looking for it. You should feel and observe the offending object. From there you can prize out the pin prick ( or pricks of broken glass ) with a sharp poker. Feel again insuring you got it all out
If you wish to avoid a puncture repair failure though preparation you can get away without it. If you do wish to prepare avoid the provided scraper using a nail file or fine sand paper. Don't apply the cement or peal off the silver backing sheet just yet.
Just place the patch on a dry run lining up over the hole. Line up the patch so the hole is right in the center of the patch. With a ball point pen trace the outside edge. If you don't allow a few millimeters larger than the patch the cement won't stick the edges where air leaks will occur specially if it is leaking from the contamination of the ink of the center circle.
There, you have a template guide of the patch helping you center the hole right in the center of the patch. The template should be at lest a few millimeters larger than the size of the patch to avoid contaminating the cement round the edges. If you wish to prepare, gently create a mat finish in the area inside the template. If a new patchy kit unscrewing the cap of the cement there will be a tin foil sealing in the glue. Turn the cap upside down using the little pimple in the top to pierce it.
Bearing in mind the ink of the circle marker can potentially contaminate the cement with a tiny squeeze dap a generous amount on the hole stretching the tube so the hole expands letting some of the fresh glue to go into it letting the rubber of the tube squeeze back closed screwing the cap back on the container.
The cap back on the container, like buttering bread with the top of the cement package spread the cement filling the template right up to the ink lines. By the time you're ready to place the patch the cement should be dry like sticky tap. Now you are ready to peal off the backing of the patch
With the silver backing off the patch spread some cement on the underside of the patch and let dry sticky. This is a helpful insurance the cement on the patch will stick to the cement you covered the hole placing in position lining up the template insuring you have the hole right in the center of the patch and insuring the edges of the patch aren't on the ink.
Rub smooth with anything round the edges of the patch. You should observe the patch is not hiding over any part of the ink lines of the template to insure there is no air leaks created in the edges.
There, if preparation hadn't damaged the tube, and you'd insured the ink from the template isn't interfering with the cement the job's done.
Now all that remains is the reassemble the tube and tire back onto the wheel and remount the wheel ready to inflate.
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