flat tires, help please

My first question is, where were the holes located on the tubes that you had to patch? Towards the outside of the tire (i.e. against the tire surface), or towards the inside of the wheel?(i.e. against the rimsurface ). If they are on the inside, towards the rim surface, the #1 suspect is the sharp edge of the individual spoke holes.(IMHO)

I ask, because I had a blow-out with an interesting cause. As it turned out, one time when I had a flat in Florida I had used a 16gram CO2 cartridge to refill my 650 tire. Unbeknownst to me that over-inflated my tire to 185psi , since I was on the side of the road and w/o a tire gauge at the time. Later, I learned all I needed was a 12gram CO2 cartridge for my 650c wheels. Anyway, once I discovered the over-inflation of my wheel, I let the air back down to just 100psi. Fast-forward a little over a year and while on a local ride BOOM, Blowout! Upon taking things apart, what had happened was the 185 pounds of pressure had (super) depressed the rim-tape down into the rim holes for the spokes. So much so, that in a few places the rim tape was cut into by the sharp edge of the spoke holes. By that I mean, it looked like someone had taken a hole punch and just punched a hole in my rim tape right at the spoke hole. That was the cause of my blowout! So, I removed all the rim tape and replaced it with new and since paid much more attention to how I refill the air in my tires...especially if/when I'm using a CO2 cartridge.

After having several flats on that same recumbent that runs 650 wheels, I was frustrated in that they only make very light duty/racing tires for it. So after several flats, I was to no end. I couldn't get a thicker tire and I couldn't stop having flats. My fix was to take my old (i.e. blown out) tubes and CUT the valve core out of them. Next, to create my own thicker tire, I sliced the tube length-wise around the inside of it's circumference. This gave me, in essence, another layer of rubber protecting the outside of my tubes filled with air. To be clear here, I had two inner-tubes in each wheel. The first inner-tube was my main (i.e. air-filled) inner-tube filled, and my 2nd inner-tube was installed atop my 1st one for an additional protective layer of insurance against flats! That setup gave me good service for several years, and in the meanwhile I developed a better eye as to what to watch out for when riding.(i.e. SUN glistening off broken glass shards in my path, etc.)

 

One other thing, I notice you are in New Mexico and I know there has been a heat-wave out there lately. Is it possible the extra hot pavement may be over-stressing your tubes?(i.e as discussed here and here)

 

While they do make them most applications that I've seen refer to using such on (lower pressure) mountain bike tires. However, DynaPlug does support using their product with road bike tires...

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Well when you are patching the tube, are you able to identify the culprit in the tire (and/or tube) upon inspection? If so it is glass, stainless steel shards from worn-out (auto/truck) tires, thorns, etc? My only other guess might be to inspect each spoke hole to look for any kind of debris, that could be getting loose and possibly causing a flat.

Other than Dave (Mtwnrocket), you seem to be having as much of a problem with flats as he did for awhile.

Maxxis Hookworms are probably about the most heavy-duty tire I've come across, but they are a bit weighty. Still, i'm surprised that running liners you are having flats. That by itself, is usually a pretty good way to ward-off flats.

 

Therein may lie another clue to what could be happening. If your tires have dry dry-rotted in the past, what about the age & condition of the bicycle tubes?

All rubber will eventually dry-rot over time (in fact Serpula lacrymans, the fungus that is responsible for dry-rot in wood, attacks rubber once it has been compromised), but there are a few things one can do to help delay the onset of such. Namely, minimizing exposure to Ultraviolet Light and Ozone and usage of a specialized protectant like Golden Eagle 303.(NOT to be confused with products like ArmorAll, which leave a 'slick' coating on the surface. See FAQ)

So have you been able to identify what sort of material(s) have caused the punctures in the past?

 

Well that's some good news, as I thought if you had not found anything then perhaps something was still lodged inside the tire causing it. I guess my worst enemy, here in East TN, had been glass shards along the roadside. However, I don't have any experience with thorns and such penetrating tires, liners and tubes!