Keep Getting Flats!
 

I have gone through 5 inner tubes in 2 weeks, and I have no idea why. It has mostly been my front tire that keeps going flat. I have checked the inside of the tire for glass/nails etc, and it is clean. I have also checked the wheel to make sure no spokes are sticking through. My tires say that they should be inflated to 87 - 116 psi, and I have tried both ends of this spectrum. First, I inflated it to like 90, and while I didn't get a flat, the tire felt so under-inflated that it slowed me down considerably, and I felt like it could damage my deep dish rims. So I inflated it, on the advice of my buddy, to 115, and it popped within an hour. This morning I replaced the tube, inflated it to 102 psi, left for work, and it was flat within 2 miles.

I have no idea what's going on, and work is getting sick of me not being able to make my deliveries. Does anyone have any advice? Please help cuz this is getting out of control.

PS I don't use a tool or anything to replace the tube, so I'm not poking it with a screwdriver or something either.

Are you using rim tape?

No haha what's that?

I don't have an answer to your question, but I do have a question for you: Are you patching your tubes? 5 tubes in 2 weeks is insane. I don't think I go through 5 tubes in a year.

Nope, I just ordered a ten-pack of tubes.

OK, here's what you do: Take your bike to a bike shop, tell them what's happening. Ask them to take a look at your rim and ask them to show you how to patch a tube. From there you should be set to deal with flats for the rest of your life.

I think we already solved the problem.... just take your wheelset or bike to your LBS and ask them to install velox on your rims and that'll take care of all unnecessary self inflicted flats. And of course what lorok said..

I think he's probably already got tape on his rims (just doesn't know what it is), but it might have slipped or something.

Ive been having many of these issues myself. Here are some of the main reasons why my tires have been going flat:

- Unnoticed hole in tube.

Just fill the tube up with air and put it in water and try to find any holes, then just patch 'em up. Its easy as hell, and you'd be surprised how hard it is to see holes w/o water.

- Debris in the rim

Anything from glass to a spoke poking through the rim tape will cause you a flat. Like people mentioned before, just take it to your LBS and have them install new/better rim-tape.

- Too much inflation

Keep in mind the recommended PSI to inflate your tire doesnt include the weight of you on the bike, so keep it 10-20 psi lower than recommendation, but still enough to maintain a good speed.

How can overinflating cause a flat (so long as it doesn't blow the tire off your rim)? There is usually a comfortable margin of error, and inflation recommendation is more geared toward keeping the bead on (which is why you can run tubulars at such ridiculous pressure). 20 psi lower than the lower recommendation sounds like a good recipe for pinch flats.

Over inflating causes a tube blowout either during inflation, or even worse during a ride when the tube finally gives out... which completely trashes a tube.... you usually end up with a tube that looks like you slashed it once with a x-acto knife....

Not true. Tire pressure does not change when rider weight is added, since the tire volume does not change, it only changes shape. Tires normally have a recommended inflation range printed on the sidewall, and that is what should be used, period. If the tire only has a maximum pressure shown on the sidewall, then just use that pressure. As has been stated by others, all tires have a significant margin of safety in the recommended inflation pressure. Underinflating tires is the single biggest reason for premature tire wear, tire failure and pinch flats.

A tube will not give out from over-inflating on a ride--- tubes stretch incredibly. Just inflate a tube off a rim and you can see that the tire is ultimately what holds everything together. You might blow the bead off--- but that is an entirely different matter. This is why the tire is rated, not the tube. Furthermore, it is highly unlikely that you can keep a tire on a rim long enough to make it to the road if you have over-inflated it to that degree. My guess is people have had the tube pinched between the bead and the rim, and that has blown out (with the tell-tale slash), and they assumed they had overinflated it (rather than mounted it improperly).

A tube blowing out at only 115 lbs sounds like a bad tube. Make sure your tubes and inside of your tires are debris free when installing them. Use a better quality tube like a Michelin. Its strange that you keep getting front flats, inspect your tires and rims.

+1

Now that there is 20 roots of this thread. Has this guy ever fixed his flats?

What do the tubes that don't hold air look like?

If they have holes on the inside circumference, you have a rim tape problem. The rim tape has to cover every tiny crescent of spoke hole or you'll keep cutting tubes in that area.

If they have holes on the outside circumference, you are getting punctures. 5 punctures in 2 weeks is a lot. If you make a hapit of always lining up the tire label with the valve stem you can see if the punctures are all in the same spot (my bet). If that's the case, you have a torn or a piece of glass or something in your tire that you haven't been able to find and remove. Find it and remove it or buy a new tire.

If your tubes seem to have 2 parallel slits, you are pinching the tube between the tire bead and rim. It's an easy mistake to make.

There's also a "star" shaped hole but that sounds like a gunshot when it happens so I doubt that's you.

Incidentally, I used to save my punctured inner tubes and patch a batch all at once. It really doesn't take much more time to patch 5 than it does to patch just 1.

I usually don't get up to the recommended psi (100 for my current setup). Whenever I get up to about 80, the resistance to the pump feels so high that I'm always afraid one more push will burst the tube.

I've always wondered why this happens.

Maybe my nervousness is unfounded and I should just man up and give it hell.

I think he is a troll, Josher. 7 posts? Im just saying.

Well, it all depends on the size/type of your tire and the recommended pressure range. For example, I have some 26 x 1.25 (32c) Paselas on a rigid MTB, which are rated 65 - 100 psi, and I run them at 80 psi which falls in the recommended range, so they are fine. Wider tires can be run at lower pressures than narrow tires without risk of pinch flats. I have some Conti Grand Prix 4000 700 x 23c tires that need a minimum of 100 psi to avoid pinch flats. As far as you bursting the tube, it just won't happen; you will blow the tire off the rim first. You can't judge the pressure by how the pump feels, so if you a worried that the gauge is inaccurate, just borrow another pump with a built-in gauge or buy a good digital pressure gauge.

Well, the fact that the OP mentions that he checked to see if spokes were poking through leads me to actually wonder if he is using rim tape ;)

I see.

My current tires are schwalbe Lugano 700 x 23c. Sidewall says to inflate to 100 psi. as soon as the gauge hits 80 psi, the pump just won't go any further unless I push it down HARD. I already blew out a tube a few months ago when I tried to go beyond that point so I haven't even tried again. The tires always feel solid but not rock hard (lol). I can just barely push the tread a few mm in with my thumb which I think (?) is just about right (someone correct me on this). Maybe the gauge is indeed inaccurate and it's reading 80 psi while the pressure is actually higher. It's my roommate's pump and i'm not sure how long he's had it. Doesn't look too old and I'm not even sure that age can affect its accuracy... Or can it?

I'm still probably going to get a new one in the near future.

Thanks for the info.

Pump design has a lot to do with how easy it is to inflate your tires at higher pressures. I need to throw my weight into my floor pump to get much above 100psi--- and for something like my Crank Bros mini, I doubt I can get above 80--- ever.

for pumps, I recommend topeak joe blow as your floor pump and topeak road morph for your frame pump.


really, there's no need to pump the tires beyond 80% your own body weight, no matter how narrow your tires are.

here, I recommend you this chart for inflation

Tire Width=20: Pressure(psi) = (0.33 * Rider Weight in lbs) + 63.33
Tire Width=23: Pressure(psi) = (0.33 * Rider Weight in lbs) + 53.33
Tire Width=25: Pressure(psi) = (0.33 * Rider Weight in lbs) + 43.33
Tire Width=28: Pressure(psi) = (0.33 * Rider Weight in lbs) + 33.33

Tire Width=32: Pressure(psi) = (0.17 * Rider Weight in lbs) + 41.67
Tire Width=37: Pressure(psi) = (0.17 * Rider Weight in lbs) + 26.67


Example: You are 150lbs running 28's

Pressure (psi) = (0.33*150) +33.33 = 82.83psi (rear)
Front Pressure = .9*Rear Pressure = .9*82.83psi = 74.55psi front

pulled off of here: http://www.bikeforums.net/showthread...tip-of-the-Day