Frequent Punctures

Riddle me this NSMB, after years of commuting puncture free, I seem to flat every week or two in the front. I'm running a cheap Rocky road bike with Schwalbe Marathon's. Tires are getting a bit long in the tooth (maybe 2 years of riding) but still seem to have a lot of life left.

I've checked the tubes, the rims and the tires and can't find anything causing the problem. They're flatting in different spots so I'm inclined to believe it isn't a problem with something sharp in the rim / tire. I've switched to different tubes a couple of times in case it was a manufacturer issue. I've re-taped the rim. I've switched the front / rear tires (in case it was a tire issue). Still seems to happen.

I am running pretty close to max PSI, around 100 to 105. Rear seems to be holding its air (after a week, it's still at 105, front is flat).

Thoughts or solutions?

Something curtting your stems like a bur in the hole of the rim maybe, otherwise I'd say 99% sure it has to be something in your tire. How many times now? More than three in a month?

Check for something embedded in the tire. I had a piece of glass in a road tire that was exactly the thickness of the rubber. I couldn't see it or feel it from the inside or outside, but it was enough to cut the tube after about 100km of riding.

Check for something embedded in the tire. I had a piece of glass in a road tire that was exactly the thickness of the rubber. I couldn't see it or feel it from the inside or outside, but it was enough to cut the tube after about 100km of riding.

I've had tiny pieces of frayed metal cable (like 3-4 mm long single frayed strand of a shifter or brake cable) that are needle sharp, but only little wider than a human hair, embedded in the tire do that. They are pretty much invisible. I found it only after I had taken the tire off and did a careful inspection/site-matching with the tire. Pulled it out with needle-nosed pliers. Could be something like that.

You should be able to tell whether its the tire contact area or the rim/spoke from the location of the puncture on the tube. Also I assume you have checked that your tube is not getting pinched between the rim and the tire bead? It can be hard to tell with some tire/rim combos, and not visible from the outside.

Given your tires aging, I would say just get new tires. If its not the tire, you have spares that you can use in the future anyway.

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Something curtting your stems like a bur in the hole of the rim maybe, otherwise I'd say 99% sure it has to be something in your tire. How many times now? More than three in a month?

I would guess 2 or 3 times a month for maybe 4 months.

I have a new marathon- $50

I've had tiny pieces of frayed metal cable (like 3-4 mm long single frayed strand of a shifter or brake cable) that are needle sharp, but only little wider than a human hair, embedded in the tire do that. They are pretty much invisible. I found it only after I had taken the tire off and did a careful inspection/site-matching with the tire. Pulled it out with needle-nosed pliers. Could be something like that.

You should be able to tell whether its the tire contact area or the rim/spoke from the location of the puncture on the tube. Also I assume you have checked that your tube is not getting pinched between the rim and the tire bead? It can be hard to tell with some tire/rim combos, and not visible from the outside.

Given your tires aging, I would say just get new tires. If its not the tire, you have spares that you can use in the future anyway.

Pretty sure it is not something in the tire as the location keeps changing. It could be something floating in the rim. I inspect every time found a small piece of metal one time but the problem continued. I re-taped just in case but there could still be something small in there.

I think your point about the spare set of tires is a good one. Maybe I'll try that. If not, might be a new rim.

A good thing to do is always mount the tire with the logo at the valve stem so I always know where the tire was on the rim [HTML_REMOVED] tube

A good thing to do is always mount the tire with the logo at the valve stem so I always know where the tire was on the rim [HTML_REMOVED] tube

I've heard the pros do that so they can find the valve faster.

And? Puncture Poltergeist?

Which Marathon in what size? 105 could be a little to much pressure depending on what tire you have. Check the specs.

If you commute on Main st. in North Vancouver past MEC it's a free for all for crap on the road that punctures tires. I had problems when I picked up a screw earlier this year. I bought a new tire from MEC (convenient that it happened out front) and then went through 3 tubes. Turns out that when I was inflating the new tire the first time I exploded the tube because there was a burr on the rim where the screw hit. I fixed the burr but the explosion damaged the side wall and made a weak spot in the new tire near the bead. I was getting pinch flats above the bead in a brand new tire. When I bought another new tire. Voila no more flats. Knock on wood. Although I watch the road for debris more along that stretch now.

Which Marathon in what size? 105 could be a little to much pressure depending on what tire you have. Check the specs.

If you commute on Main st. in North Vancouver past MEC it's a free for all for crap on the road that punctures tires. I had problems when I picked up a screw earlier this year. I bought a new tire from MEC (convenient that it happened out front) and then went through 3 tubes. Turns out that when I was inflating the new tire the first time I exploded the tube because there was a burr on the rim where the screw hit. I fixed the burr but the explosion damaged the side wall and made a weak spot in the new tire near the bead. I was getting pinch flats above the bead in a brand new tire. When I bought another new tire. Voila no more flats. Knock on wood. Although I watch the road for debris more along that stretch now.

This raises an interesting point. A while back, I did hit something going over the bridge (didn't see it, guessing it was a rock) that caused the bead of the tire to slip off. I didn't notice until I was almost at the office and my tire was flat. The bead looked fine but possible there is damage there.

The long and the short is I've been trying to ride a bit more gently over the bridge and it seems to be working furiously touches all surrounding wood. If something comes up I'll likely spring for a new set of tires.

I believe it is the HS 420 in a 25C, lists max PSI as 110 on the sidewall.