joelcool

I upgraded my wheelset last year after a spoke broke - I figured 17k miles on my stock wheelset "justified" getting a carbon wheelset. The carbon set is wider, so I've been running 25cm tires. I also changed my pressure from 120 to 110. Tires are Conti 4000S before and after. I have been getting a lot more flats since this change. My flats seem to be "in and out", so nothing has been stuck in the tire.
Anyone else make this kind of switch and see a change in frequency of flats?

rm -rf

no change with tire size changes, and I use GP4000S also. I rarely get puncture flats, maybe one every 8000 to 12000 miles. No pinch flats for 3+ years, then I got two this year, both on larger, sharp edged gravel pieces that I hit fast on downhills -- that's random bad luck for me. I try to ride in the right tire track, since car tires kick any debris out to the edge of the road. I avoid shoulders and unswept bike lanes.

Are you sure there's not a tiny sliver or bit of wire stuck in your tire? Are these larger cuts, or tiny pinholes?

Do you align the label with the valve hole, so that after locating the hole in the tube, you can carefully inspect that corresponding area of the tire? Then reoccurring punctures at the same location will be easier to spot.

At 110 psi, pinch flats aren't likely. Pinch flats have one or two small slits (a "snake bite") on the inside / rim side of the tube, where the tube was squashed flat between the tire and the rim edge.

Tire pressures
I'm about 170 pounds. I use 15% less pressure on the front wheel. There's less weight on the front.
My 23mm tires measure 26 mm on my very wide HED rims. I use 80-85 psi front, 95-100 psi rear.
My 25mm tires measure 29mm on the rims. 65-70 psi front and 80-85 psi rear.

TrojanHorse

"a lot more flats" is unfortunately vague.

How many? Same tires? Have you found the source of the flat? Run a cotton ball around the inside of the tire and it will snag on any tiny protrusions that may be causing your flats.

Personally, I tend to get flats in bunches... nothing for 6 months and then 2 on a single ride. It usually means my tires are about done or I didn't find the source of the first flat.

Aubergine 

HTupolev

I switched my Emonda from 23s to 25s, Bontrager R3 Hard-Case Lite for both, and didn't notice a difference.

If anything, my experience is that going much wider and much lower-pressure might reduce punctures. The 53mm slicks on my gravel bike have paper-thin casing and no puncture protection layers, but I seem to flat them less than I flat my skinny road tires.

rumrunn6

not me. only flat I got after swapping from 23 to 25 was from a rim tape slip, spoke hole

CliffordK

I don't understand what you mean by in & out flats.

I'll randomly run 23 or 25 tires, and don't really notice much difference in flat frequency. Perhaps a flat every 1000 miles or so.

The cause varies. Radial wires, occasionally a piece of glass, rarely a pinch flat (unless it is secondary to another flat), etc. I hand an avulsed valve.

The last one was a slow leak on the bike, over a few days. Pumped it up a few times. Then finally pulled the tube. Tube has now been holding air for a week without leaking.

joelcool

Thanks for the replies. By "in & out" I mean there is nothing left in the tire like a radial wire or thorn that would flat a repaired / replaced tube. Today there's a clear cut in the tire that goes thru, and a small hole in the tube, which I patched. None of my flats have been pinch flats. I think most of them have been from riding over small rocks just wrong or some other small thing that's sharp enough to cut my tire.
In terms of frequency, I understand that's vague, but since I don't record every flat I get I don't have any hard numbers. But it "seems" to me that I'm getting more than twice the flats I did with my old wheel set, maybe as many as 5X.
Maybe it's just a wave of flats I'm experiencing and it will go away. One can hope.

rubiksoval

I get the flats in waves thing. I'll go a year or more without a flat, then get 3-4 in a few weeks. It's madness.

Iride01 

The big question is whether you are careful to determine what caused each flat. Don't just assume a puncture is from the road. When you repair or replace the tube you need to do it in a way that you can see whether the hole or tear in the tube is oriented toward the tread of the tire, the sidewall or the rim and spokes. Since changing to a different brand tire last year, the only flats I've had were from the wheel rim strip needing to be replaced or my own installation carelessness. Previous tires had just as many flats from rock shards, glass or other road debris as the did the non-tire related issues. The new tires are not even advertised as being built to resist puncture.

There might be something to them being wider. But I went from 23 to 25 mm tires too and am not having that issue.

Mike F

Knock on wood but I got a flat at least once every 3 months with GP4000s with23's. New bike came with different tires (Spech Turbo Pro's 26) and I haven't has a flat since. Could be luck...

Dopefish905

u235

I've had some file threads that got a lot of "in and out" flats. Tiny sharp debris gets stuck in the thread and eventually works it's way in through. Don't see how a 4000 would have that problem. I'm going to side with it's random. Me personally, I can go 1000 miles with no flats and then get 4 in 5 rides including both tires on the same ride from different causes.

rm -rf

Almost 4 years ago, I got a big sidewall cut on the second ride with my very wide HED rims (20.5 mm inside, 25.5 mm outside). I was worried that the wider spread from the rims exposed the tire sidewall to cuts, and thought I might need to use stiffer, more cut resistant tires. But I've never had another sidewall cut. It's been about 16000 or 17000 miles. It's funny how tire experiences work.