Get this, I bought four Kenda tubes off Ebay, and every one of them has small pinhole leaks in them after pumping them up to 115#. They all went flat over night. So, I figured it was just bad tubes from old stock or something.

I then went to the LBS and got new Giant 700x19/23 tubes, and replaced the Kendas. Well, today, the rear tire is still inflated, but the front one went flat.

What the heck is going on? I can't keep wasting my money on tubes. I know I am not pinching them when they are installed. I have installed countless tubes in the past, but these just won't hold air. I am afraid the rear tire is going to flat too.

How long should tubes hold their air? Am I really doing something wrong? Why are all these new tubes leaking?
Or, should I just buy a patch kit and keep patching them?

Patriot

What type of flats are they? In other words, where's is the air leaking from?

Do you leak test them before installing? I know it sounds redundant, just plain not necessary but if you are having a bad case of the flats you'll be able to determine which way to go with the troubles. Leak test them, coat the tube and inside of tire with talcum powder, partially inflate the tube to hold it rigid and in place when in the tire going on the rim...also helps with keeping tube away from rim and wire bead. Also, run your hand around the inside of the tire to determine if you've some cord or wire protruding that causes pinholes.


Olds

I have to admit, I usually don't dunk them underwater, unless I find a leak after I have installed it. Then i look for the leak so I can patch it. But, I now have 5 tubes that have leaks, and no end in sight.
I use baby powder too, but just enough to dry the tube, then wipe off the excess.

How much do you use?

Patriot

Are you getting the same flat over and over ?

May be the Tire, or wheel.

No, the holes are in differant spots, so it is not the rims. I inspected the rims, and everything is fine.

Also, I am using Performance cloth rim tape, and Vittoria Rubino Pro 700x23 tires. (All brand new stuff)

I even install the tires by hand without using my levers. I have gotten very good at it now. LOL

Patriot

feel around the inside of the tire for any sharp objects, or anything out of the ordinary. do the tires have a presta valve? if so are you screwing the valve shut after filling?

buy a patch kit for 2 dollars. they are extremely easy to use, and you can patch these pin holes again and again. the tube i have on now has 6 patches!!!! (i will probably relace with next flat, and i only use the patches when it is a very small hole.

I will start patching these pinholes, but how often do they occur? And how long should these tire hold pressure? Mine are only holding pressure for a day or two before going flat.

Patriot

P.S. I checked the inside of the tires and they are good.

It's not the tubes. Patch the holes and they'll be good to reuse.

Now to solve the repeated flat problem. Whenever you are having frequent flats, it's important to figure out what is causing them.

1. Where are the "pinhole" leaks?

If they are on the inside circumference of the inner tubes, you have a rim problem. In most cases, the rim tape has migrated over to one side and exposed a tiny crescent of spoke hole. That's all it takes. Carefully replace the rim tape to cover all of the spoke holes and you're good to go.

If they are on the outside circumference, you have a thorn or a piece of glass caught in your tire. I always install my tires with the colored label exactly liked up with the valve stem so that I'll know exactly where to look for the thorn. They're not always easy to find. Actually, a couple of times I haven't been able to find the thorn but I know it was in there because replacing the tire solved the problem.

I have had pinhole leaks in various places. Another problem I have noticed is that it seems no matter how careful I am , the rim tape migrates back and fourth, and yes it does reveal some of the spoke holes, but I have gotten good enough to keep it from moving.

Maybe it is just the rim tape, but the kind I got is the "Performance" brand of cloth tape, and it really doesn't stick in place very well. I cleaned the rims thouroughly before applying the tape.
Maybe there is a better brand with stickier glue.

Some of the pinholes are on the sides, even the outside of the tubes. I haven't even ridden the thing yet. grrrrr.......

My first attempt at using some "Slime" green tube patches, was not successful, and they leaked badly. Do you have to let it sit for a while before pumping up the pressure? It does not say that on the instructions. The old glued patches I used to use, needed a good hour or two to set before use.

I am getting really frustrated here.

Patriot

Ideally, the rim tape should completely cover the rim from flange to flange. Unfortunately, Velox, for example, doesn't come in enough different widths for every rim. 17mm works for most road rims, but I assume your Performance rim tape is about the same and it's obviously too narrow.

One possible solution is to use that nylon reinforced strapping tape. It's easy to rip down to the exact width that you need. If you ever need to get it off, however, you're facing a royal PITA.

The rims are old Araya rims that use the 11mm tape, it sits flat down inside right where the spoke holes are, and that's it. Then there is a step up to where the clincher edge is at, so cloth tape won't work if it is wider, ,as it won't curve right. If it was some sort of rubber, it might work to use some wider stuff, but not sure how well it would form inside the rim.

Which is better, the cloth tape or the synthetic stuff, like the green stuff made by "Slime"?

Patriot

Velox rim tape is the standard. It sticks and does not move.

Five leaks in a row is not a tube problem. You have something wrong inside the tire/rim.

yes. change that rim tape baby. velox is calling for you. or black electrical tape twice around to make sure you cover the holes completely.

sd

I still don't believe that so many riders don't know how to patch a tube. This is cycling pre-k.

The patch itself could actually help if the rim is the cause as it would provide additional protection in the same spot, assuming you orient it the same way.

I always use the tip-top type patches, with glue. Use the sandpaper. Make sure the glue covers the entire area where you will apply the patch, not just around the hole, use your CLEAN finger to spread it. Just make sure the glue dries BEFORE you apply the patch. Press the patch on hard, use the barrel of your pump to press. I haven't had one fail in 20+ years of using them. And I will patch anything that the patch can cover, not just pinholes. The patching process takes less time than removing and mounting, so it doesn't add significant time to the total job. I only replace the tube if the hole is near the valve or too close to another patch. I took the tire off my old wheel and found a latex tube with 10 patches on it! (All from my Seattle days, I almost never get flats in NYC.)

I am going to wrap electrical tape to hold the tape in place. The more I think about it, I think that may be my problem.

Patriot

Zacster, if you want to insult me about whether or not I know what I am doing, take it somewhere else, like "Bike forums for arrogant snobs". I have been patching tires since I was 5 years old with the older method of plain patches and glue. I am well aware of how to patch a tube.

My question was concerning a specific type of patch that comes prepared with adhesive, a brand and type I have never used. So, keep your arrogant comments to yourself.

Electrical tape is something I have never used before but will give it a try. If it works, kudos. If not, then I will try other things.

I just got done trying the electrical tape, and will watch it for the next few days to see if that did the trick.

Patriot

If your having trouble with the tape, get rim strips instead. It is a stiffer plastic and does not adhere to the rim.

I will definitely consider going that route if the cloth doesn't work. But, since i just covered all of it with electrical tape, then I will give it a shot first.

Patriot

After two days now, there have been no more flats, yet.

Looks like the little electrical tape trick worked very well, it held the cloth tape in place so it could do its job. I used one nice and tight strip all the way around. I figured out it had to have been the rim tape, as every time I took the tires off, the tape had moved in various places, ever so slightly from the center.

Thanks for the tip shaq-d.

Patriot

Wow I don't know that I have seen rim tape move as much as yours is. I did have a ride partner buy new wheels....lots of flats.....mid week long tour two loops of E tape... no problem...for a time. It ended up being burs from the drilling of the rims that were never filed down. He is an old mechanic and still it caught him.

Keep us up-to-date with what it is.

Cheers

My rims use that really skinny 11mm cloth tape and the tape really haas a tendency to move around quite a bit. Thus, the spoke holes get a little exposed. And, with such thin tape, it doesn't have to move much to do that. The rims that use wider tape tend to stay put better.

Patriot

Patriot, the common opinion from experience in my club is that the self adhesive patches are only good enough to get you to the end of a ride, then replace the tube. The glue on patches will last as long as a tube that gets no flats ever, maybe longer. I use the patch kits from REI, because the smaller round patches don't entirely cover the tube past the edge when deflated. They are great for puncture holes. The glue in those kits dries in about 5 minutes, maybe a little less. I saw a guy repairing a flat on an organized ride, and the outside of the tube had so many patches that it looked like he'd glued Tuffy Tire Liners on the tube.
I was getting flats on some older rims, and put Velotape on, and they stopped. It does sound like your problem could be the tape. Stick with the cloth, it should work better as long as the electrical tape holds it in place.

hmm, you might want to recheck your tires for glass as small shards can often be overlooked when they are deeply imbedded in the rubber and can be easily poking through the tire on the rim side...if they are just pin holes, then this might be the case....if you were to fill up some of the old punctured tubes, where are the punctures, on the inside of the tube closest to the hub or on the outside, in contact with the tire?

Now that I look at it, they are on the inside, where they seem to line up pretty well with the spoke holes. Which is why I am thinking it is the rim tape problem.

Patriot