This may seem ridiculous, but I cannot figure out what is giving me flats to save my life. I have a set of Weinmann DP18's and I use Armadillos. Considering my setup it would seem like flats wouldn't be a problem, but I have literally been through about 20 tubes just this summer. The really strange thing is that they keep blowing at the exact same spot on both wheel. About a cm or two from the stem facing the rim. I have checked my tape every time I change the tube and it appears to be perfect. In fact everything appears to be perfect and i've had my tubes changed by about 4 different people. WHAT IS WRONG WITH MY WHEELS!!! Please help

Your tubes will tell you exactly where the problem is. You just need to look more carefully and you'll find it. It is likely to be a small burr of aluminum on your rim that you would have to file down.

mander speaks the truth. happened on a wheel of mine. couldn't find it, then really scrutinized it under a bright light and found it, then sanded.

on a friends wheel, it was the same exact spot over and over, but i couldn't find a bur. we just set it aside, he had another wheel, but im thinking:

Maybe just add a few pieces of electrical tape on top of the rim tape?

Check the rim itself for a rough edge beyond where the rim tape covers. Don't let the air pressure get low (pinch flat). Maybe check the tire for a rough spot. Anything puncture the tire and still there ? Although it might be the tire went back on the rim in a different location each time. 20 tubes ? I'd patch it this time, see if the patch is sufficiently thick enough to cover the tube where the puncture is occurring after smoothing out a rim or whatever else to find a bur ?

check rim tape for exposed spoke holes or nipples showing. That's most likely it if it's at the same exact location. Re-tape and u're set.

What kind of rim tape are you using? This is what happened to me with the original plastic rim strip that came with my bd wheels, which I replaced with Velox tape:

I have the same problem with my DP18s and have been trying to figure it out for months. Apparently it's because of the profile of the inside of the rim. I have 2 strips of 7mm? rim tape in the center crevice, and 17mm over the entire thing, but I haven't had a tube to test it on yet. With one 7mm strip in the center and 17mm over it it lasted for about 50-60 miles. If all else fails my lbs told me to try putting a thin piece of weather stripping throughout the the whole middle of the rim and then taping over that.

https://www.weinmanntek.com/Products/RACE/DP18.htm

I kept getting flats over and over, and it was my rim tape. fixed it right up, good to go

Stock rim tape sucks, hands down. Velox all the way, seems expensive at first but it doesn't matter when you calculate another 20 replacement tubes.

I checked the inside thoroughly, took the tape off (Velox) and everything was totally smooth and looked right. Before this last tube blew I tried putting on of those rubber patches over the tape just to give a little bit of extra padding (apparently not enough). I guess I will go ahead and try 3 or 4 layers of Velox tape and see what that does for me. Just seems ridiculous to have to go get new rims when there is no problem that I can find... other than the financial ruin that buying tubes is sending me into.

How long have you used the velox on it?

3-4 rim tapes means you won't be able to mount your tire.. ha.

One layer of Velox tape only. More will only make it impossible for the tire to seat properly. Oh, use the wider 16mm on most rims.

Are you sure you're not pinching the tube when you mount the tire? If possible, don't use tire irons to mount the tire; just use your thumbs. Put some talcum powder on the tube so it doesn't stick to the tire casing or rim and put enough air in it so it takes its shape. Make sure the tire bead is seating properly and not pinching the tube against the rim. Make sure the valve is centered in the rim hole.

It happens for no reason, there's not even depressions in the rim tape where the spoke holes are, but the tube still blows out.

This sounds like the tube is getting caught/pinched between the tire bead and the bead seat at the stem. The rubber around the base of the stem is thicker than the rest of the tube, and tends to be the area where it will push its way under the bead.

This happens with certain tire and wheel combinations, especially if you tighten the valve nut before inflating.

1. I would go with cloth tape that covers completely edge to edge.
2. Put the knurled nut or a washer on the inside, meaning before you poke the stem through the rim hole when installing.
3. As you are inflating, keep pushing on the stem and checking that it's free to move.
4. If you use another nut on the outside, just barely snug it down and only after you reach full inflation.

are the holes identical each time?
single hole? snake bits? gashes? how big?

It's like a little bubble until it finally bursts out. For me, at least.

Exactly! It makes no sense! It is in the exact same spot on both of the rims EVERY time with EVERY tube. It's not right next to the valve it's about a cm away. I know I'm not getting pinch flats because I only use my hands to instal (no tools) and I push on the stem multiple times to make sure it's not pinched. And the tape is always completely in place and smooth where it blows out.

What tires?

Armadillos

Oh yeah, sorry. It started happening when I started using Maxxis Re-fuse... I think I read somewhere that they are pretty similar tires?

i had a little metal shaving that i could feel by pinching the tire, and could only see by pulling on the tire (like opening a bag of chips). tweezers got that $^#*#er out

It's on the inner diameter of the tube, not near the tire.

Here is what i'm dealing with, on every single tube it looks the exact same

https://i335.photobucket.com/albums/m...-14at15363.jpg