performance vs. puncture protection

A problem I've been trying to solve for several years so I'll share my experience. Much of my riding is on pavement covered with broken glass. I remember one flat from a wire and one pinch flat, all of the others have been from glass. Through the years I'd used Continental road tires with great results, maybe 1 flat every 2 years. But when I got a new bike which could accommodate wider tires all that changed.

I set up the new bike with Rene Herse extralight tires, then tried Soma Supple Vitesse EX, all with butyl tubes. Those tires have thin casings and flatted constantly, like 1 flat every few weeks or every 100 to 200 miles.

Next I tried more gravel-oriented tires with some puncture protection: Schwalbe G-One (original V-Guard), GravelKing+, GravelKingSK+, and Rene Herse (Endurance). I got fewer flats but still too many. The last incident involved one piece of glass and two flats. Crunch, hiss, hiss, curse.

Back to road tires. The widest I could find was the Continental Taraxagum in 35 mm. Zero flats in 800 miles and not even a nick in the tread while I was constantly pulling glass shards out of my gravel tires. From BRR I suspect the Pirelli Cinturato would be as good or better but I found 35 mm smaller than ideal for the roads I ride. So I tried the Schwalbe Marathon Almotion (new HS603, V-Guard) in 40 mm and the Soma Shikoro in 42 mm. So far no flats with either but not enough miles for that to mean anything. Both feel slower but more comfortable than the Taraxagum.

Then I read a good review of the Panaracer FlatAway kevlar tire liners. Not wanting to toss my expensive Rene Herse tires I installed the liners in them. Still excellent performance and no flats yet but not many miles. I'll ride this combination long enough to find out.

I've also tried a variety of tubes: Schwalbe butyl (SV17, SV18, SV19A) and Tubolito (CX/gravel, city/tour). I've had plenty of flats with all of them. I've found Rema glue and patch kits make easy, permanent repairs to butyl tubes. The Tubolito patches fail more often than not, usually with a slow leak, but one or two patches have remained airtight. The CX/gravel Tubolitos are very light and probably have lower rolling resistance than butyl though I'm not sensitive enough to discern the difference. The city/tour Tubolitos are close to the weight of light butyl.

I just installed a pair of Schwalbe Aerothan SV17E tubes in the Rene Herse tires with FlatAway liners. The Aerothans are very light and fit tires from 37 to 50 mm (note the instructions discourage reinstallation in a different size). That combination has excellent comfort and rolling resistance (for a staggering price). I haven't yet tried to patch one yet but one Aerothan review mentioned patching didn't work well.

IMHO the Tubolito CX/gravel and Aerothan perform well but might have to be replaced after every flat. I carry 2 light butyl tubes and a glue/patch kit just in case. For me Tubolito and Aerothan are too expensive to use in circumstances where flats can be expected but I've been happy with them in tougher tires.

Thanks.  I've never heard of "Panaracer FlatAway Tire Liner"  Sounds interesting.  I tried tire liners in the past, but they actually caused flats as they were so stiff they wore into my tubes 2/3 the way through a 3+ hour ride.  I couldn't figure out why I was losing air, but the longer I road the worse it got.  The damage was obvious when I took things apart.

It the kevlar liner does sound like it is adding what some tires incorporate into their flat resistant tires anyway.

That is a bit worrisome that the Tubolito & Aerothan may have to be thrown out if they get a puncture (i.e. not reliably repairable).   I could see myself using them on the front, as punctures happen on my rear 90% or more of the time (Can't say I've ever punctured a front tire, just a rare pinch flat).

Curious - it there a reason you don't want to go tubeless?  

Where are you riding that you're getting so many flats?  I've had like 3 in my adult life.

Maybe this would be a good time to go tubeless. I've also found that tires with any tread tend to be more flat-prone, especially wide, low-pressure tires. My guess is that the tread traps sharps and give them an opportunity to puncture where higher pressure slicks tend to kick them away.

It seems that you like light , fast (aka fragile) casings. Tubeless helps with weight and RR also, as I'm sure you know. IME tire liners just add weight and drag and don't help much with punctures.

BTW, the Pirelli you noted: BRR tested the CX version, the gravel is available in up to 700x45 and 650x50. But they're still wide, low-pressure, and treaded.

Thanks for all the helpful comments!

I ride in Alameda and Contra Costa counties in the San Francisco Bay Area. Many of the roads are pretty torn up though maintenance is improving. Unfortunately the best roads for daytime cycling are also the best roads for nighttime drinking so a good fraction of what pavement remains is broken glass. COVID-19 has reduced traffic on many residential streets, which is great, but increased traffic on other roads which used to be nearly empty during working hours. That makes it necessary to ride on the unswept shoulders. And I don't ride on trails due to the total lack of social distancing.

Volsung, it's good to hear you've had so few flats in your adult life. I'm in my seventies but not sure I've entered adulthood yet.

The FlatAway tire liners are strips of kevlar felt either 30 or 40 mm wide and maybe 2 mm thick. They're light (25 or 38 g), soft, and flexible but hard to cut to length with scissors. So far I haven't noticed any problems but I haven't ridden many miles with them.

I've thought about tubeless but I've read the major benefit is ability to run lower pressures without pinch flats. I run pressures around 50 psi in 40 mm tires or 45 psi in 45 mm tires and I'm not a fast or aggressive rider so I don't worry about pinch flats. Also my work space is severely constrained so any kind of exploding goo incident would have severe domestic repercussions. But I could be convinced if nothing else works.

I looked at the Pirelli Cinturato gravel tires but noticed they're not constructed like the Cinturato road tires. The road tires have kevlar belts under the tread and kevlar fibers in the tread. BRR rates their tread puncture resistance at 20, the highest figure I've seen on that site. The gravel tires look great but lack that protection, BRR rates their tread puncture resistance at just 8 (cross version).

I was a late convert to tubeless but am now a deciple.

The other benefit of tubeless (besides lower pressures), is that many smaller punctures will self seal and you won't need to repair it. Also, I carry a set of Stan's darts and when I do have punctures that are too big to self seal, I just dart the hole and I'm back up and riding without ever having to remove the tire.

You could run even lower pressures on tubeless and perhaps just roll over the glass and never puncture the tire, but on the road you may start to have issues with tire wiggle if you went too low on the pressure. I run my 45's at 25-30 psi tubeless but on those tires I'm 75% gravel 25% (bad) road.

Lastly, regarding explosions. I've had only one and it was after hitting essentially an arrow head while riding fast down a logging road. It was the only time I've had to use a tube to repair a hole in a tubeless and if I'd had a tire boot I could have used that instead. I have had one set of tires unseat while sitting, Gravelkings. I have read, and can attest, that Gravelking tires are the hardest (in my experience) to get to seat and seal tubeless. Everything else I've used has never lost pressure (or sealant) while sitting. Even the Gravelkings that lost pressure in the garage only bled a few cc's of sealant, but they were hanging up.

sincos wrote:To this day I still don't know how it impaled itself so perfectly, but I've since patched the tire and it's working great. While fixing it I saw that I had picked up a construction staple at some point as well and hadn't even realized it. I realize that the plural of anecdote isn't data -- but try riding home on that with tubes.

Great pics! Pointy screws seem to have an uncanny ability to insert themselves in tires. I've never picked up one in a bike tire but many in car tires. They're about the only common hazard which can penetrate steel belted tires. Good thing you didn't try to unscrew it until you got home!

When I see a screw on the road I stop to pick it up (where safe) in the hope it won't find its way into someone else's tire. So far that hasn't helped my flat tire karma.

sincos wrote:I've also found that tires with any tread tend to be more flat-prone, especially wide, low-pressure tires. My guess is that the tread traps sharps and give them an opportunity to puncture where higher pressure slicks tend to kick them away.
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After a lifetime of experimenting, I have to agree with you.  A wider knobby front tire at lower pressure is more likely to pick up road debris and throw it at the rear tire (where it is probably more likely to trap it and hold onto it).  

Commuting on crappy conditions, I will get a flat a lot more often on wide knobby tires than slick road tires.  I can't say I have ever gotten a flat on the front caused by road debris.    

I've had nails (like above) on my tires (rear) also.  Even on slicks.

stu wrote:
I've thought about tubeless but I've read the major benefit is ability to run lower pressures without pinch flats. I run pressures around 50 psi in 40 mm tires or 45 psi in 45 mm tires and I'm not a fast or aggressive rider so I don't worry about pinch flats. Also my work space is severely constrained so any kind of exploding goo incident would have severe domestic repercussions. But I could be convinced if nothing else works.

This is true, and the biggest benefit.  But for someone getting flats like yours, its going to be a big help too.  Its going to seal just most any puncture that isn't a tear.  (low TPI is your friend here).   

The only hassle is on setting up the tire.  Once its on the wheel, you are good to go.  Just top off the sealant every ~6 months, and don't let them sit idle for more than a month.

You won't be taking the tire off until the tread is worn out.

chas wrote:Commuting on crappy conditions, I will get a flat a lot more often on wide knobby tires than slick road tires.

It's possible most knobby tires have softer rubber, dunno. The Continental road tires I've had (GP, GP 4 season, Taraxagum) seem pretty hard and don't even show cuts. Other slick tires (Soma SV, Rene Herse) get a lot of cuts and I've picked a lot of glass out of those before they go flat.

That said, I'm sure tires with closely-spaced tread blocks are more likely to hold glass shards. They certainly hold small stones.

I can't say I have ever gotten a flat on the front caused by road debris.

I'd guess 80% or 90% of my flats are on the rear. Could be the extra weight. Maybe I've been conditioned to steer the front around sparkling objects. Or I might wipe the front more frequently. But my best guess is the puncture gods know rear tires are harder to fix.

Another anecdote here--but since  I went tubeless on my bikes about 5 years ago, I have had no more flats while road riding (which is often mixed with some gravel or dirt riding). Admittedly, I avoid construction sites and other high risk areas as best I can.  I do have one set of wheels for my touring bike loaded with tubes which are sealant filled and, by the way,  have had no flats on this set up.  Many times I have pulled thorns and other sharp objects out of the tubeless tires which sealed with  the sealant and never required anything else. I fully admit that I don't run high pressures ( almost always 35 psi and below) and my smallest tire size is 38 mm.  My overall suggestion is that  tubeless is a game changer if these tire size caveats fit for you.  

Agreed.  After many years of tubeless and no flats (but a fair amount of penetration), I finally got some pinch flats this spring.  I did get them to seal, but did have to use my portable pump for extra air, as rim leaks certainly don't fix themselves automagically.  ;-)  

What's a pinch flat with tubeless? The closest I've come was a big burp that sprayed sealant over the back of the seat tube and lost a lot of air in the tire, but it sealed right up and didn't come close to damaging the tire or leaving the bike unrideable.

I have never had a true pinch flat on tubeless tires--but I have had a small burp of air and sealant when I was too low in psi to keep the tire on the rim.  Of course, almost no flats is big after going tubeless, but tubeless also allows riding with lower pressures giving a noticeably softer and likely safer ride.  

sincos wrote:What's a pinch flat with tubeless? The closest I've come was a big burp that sprayed sealant over the back of the seat tube and lost a lot of air in the tire, but it sealed right up and didn't come close to damaging the tire or leaving the bike unrideable.

What were the circumstances leading to the burp?

sincos wrote:What's a pinch flat with tubeless?

That is what I have said for years too.
But I had a pair of them this spring.

40mm tires, one was single track, one was near a railroad track (with those 2" sized gravel they use on railroad beds).  2" gravel vs soft 40mm tire = rim pinch (and in this case a hole).

I got both to seal - just had to lay the wheel on its side and futz with it so the sealant pooled/sloshed near the rim.  Took some time and about two tires worth of air, but I was going again in 5 minutes.  

chas wrote:
That is what I have said for years too.
But I had a pair of them this spring.

Good to know! Had no idea that was a possibility.

Stu: I hit a big pothole at speed while running very low pressures (24-25 psi. This was when I was experimenting with air pressures. Still, better than at 55 psi, where it felt like riding on a beach ball.)