I’m still getting rare pinch flats. I’m using a Stans tubeless setup, and currently some pretty meaty Maxxis Exo tyres. This setup seems to be pretty good, but not perfect. I’m still looking for that holy grail of an unpinchable setup.

In actual fact, what usually happens is that I hear a rock ding the rim, then I get a slow air leak. The hole in the tyre (if there is one) on the tread side seals instantly with sealant, but often I get a small air leak around the bead, I think because the pinch has caused the tyre to burp a bit. It’s definitely a ‘pinch’ mechanism but the main problem is still air leakage at the bead. Anyway, I’m calling them pinchburps. Sometimes a bit of furious pumping will re-seat the bead a bit and seal the tyre, but often it’s not salvageable and I end up using a tube.

What do the experts of STW recommend?

1) ProCore? I haven’t seen many reviews of this. Maybe it’s the answer. It’s expensive and heavy, though.

2) CO2 and plenty of instant pressure to reseat the bead every time? I’ve never really got on the CO2 thing, still using pumps.

3) Getto tubeless a la Jared Graves? I imagine this *might* allow the seal to remain even when the tyre is (momentarily) rolled off the bead.

4) Something else?

4. Stiffer sidewalls with pinch protection. The Exo ones are nice but they’re nothing like Super Gravity or dual ply, or even Protection + Apex. And check your pressures before each ride!

Run more pressure.

Correct tyre pressures

I don’t really believe in running more pressure to prevent pinch flats. It works up to a point (I’d estimate around 30psi) but beyond that you lose grip with no increase in protection.

Anyway, I run 28psi which is on the higher side for my weight. I checked my pressure before Sunday’s ride (with puncture that prompted this thread).

If you don’t burpypinchezz its a stiffer carcass as the others said. EXO is nowhere near the stiffness or strength of dual ply or super gravity construction. They weigh more but can run lower pressures. But you can’t have your cake and eat it.
Specialized grid casings seem a better compromise to me compared to EXOs

Schwalbe Super Gravity tyres are a bitch to get on and once seated on the rim take a fair bit of effort to get off. Not like baggy old Maxxis!

Are they TR Maxxis?

Line Choice.

After that and accept that if these are very rare events take some CO2 and blow the thing back up with that or a pump.

If you are pinching the tyre and ‘splitting’ it up by the bead, then you either need to run higher pressure to combat the bottoming out effect of the tyre between the rim & rock or run something with a thicker sidewall to compensate.

Generally the only flats I get tubeless are pinch flats, and the don’t tend to seal very well (or at all) because it’s right up the sidewall where the sealant doesn’t really get to. If the tyre is still in good nick I’ll fix it with a worm plug, as that tends to seal them up fairly well.

In my experience, I’d be very surprised if it’s a burp you are talking about. Chances are it’s a hole in the sidewall, as mentioned above.

None of your ideas will help. The only options are; tougher tyres, more pressure, pick your lines better, or slow down.

Maxxis EXO are not a tough tyre if it’s fast, rocky stuff. Compare one in you hand to something like a Super Gravity Schwalbe & you will see why.

There is a reason why they have bought out the Double Down casing. It’s tough tier than an EXO,must not dual ply tough. Pretty ideal for a rear tyre if you’re racing, or riding rough, rocky stuff.

As above Double Down will solve your issues, but you wont see it for a while on most Maxxis tyres, and when you do alot will be the new 2.5 WT format which you might not want.

In the mean time I would recommend taking a look at the WTB range. The ‘Tough’ tyres all run a 120TPI double casing (same as Maxxis are introducing) and since our Enduro team switched over we’ve gone from at least one burp/pinch/blowout per race to none since the switch.

You’re after the moon on a stick.

Hob nob and ben +1.

If your riding full suss maybe try a little less rebound damping and/or more compression damping. Maybe the shock is packing down from repeated impacts?

From the OP description, i think the issue is more about the tyre being pulled off the bead seat than leakage through hole in tyre sidewall?

If this is your issue you need to look at your tyre/rim set-up. Building up the central portion of the rim with more yellow tape should maintain seal if only a small area of the bead is pulled. Or for a more secure setup run a rubber rim strip over the normal yellow tape.

I’ve been impressed by the WTB “tough” versions.. not light though.
Although I seem to be going though a spate of pinching the front tyre a lot at the moment…

WTB trail boss tough, fast R, minion exo 3c F

Maxxis have a new ‘Double Down’ casing coming out that sits in between EXO and DP. Adds about 100g’s to an EXO tyre weight.

I have been suffering with many of the issues Hobnob describes.

I split the tyre at the bead which can be repaired but it is a pig when racing.

I have just gone to Super gravity and higher pressures to try and stop the problem and to protect my carbon rims… found both front and back cracked on inspection this week…. gutted!!

1) ProCore? I haven’t seen many reviews of this. Maybe it’s the answer. It’s expensive and heavy, though.

I’m using it and I haven’t flatted since May. I flatted a lot before that, tubeless or otherwise, despite my riding being a lot less lairy. It’s changed my riding, things I was wary of before I just point the bike at and get off the brakes now. It took a bit of tinkering with tyre pressures before I found one that was comfortable for my weight, bike and general use, once you’re below 20 differences between single digits of PSI become a lot more apparent.

It’s expensive, it’s not for everyone, it won’t be indestructible, but given how much time and frustration it’s saved me out on trails with the HT, I’d buy it with my own money.

Edit: I’m not the kind of rider who notices a few hundred grams here and there, but the weight difference is similar to the difference between exo and dual ply.

Another vote for Procore.

Ran the early development dual-valve version for a week in Finale last year and was the only one in our party not to pinchflat all week.
Will hopefully get my hands on some production ones soon.

Until then, the only things that have come close are the biggest volume Maxxis dual-ply or Schwalbe supergravity I can get my hands on, run tubeless with Stans.
EXO are useless. They are made of tissue paper and won’t last a day.

This do?

This thread is quite timely after I flatted my tubeless rear tyre last night. Tubeless has definitely reduced the number of flats I get, but hasnt eliminated it.

I dont want to run heavier tyres than current, and I dont want to use procore or similar, I dont want to slow down, and I dont want to have to worry too much about line choice. (yes I want my moon on a stick).

I wonder if there is a better tubeless sealant which is maybe a bit thicker than the stans stuff. I reckon if it was a bit thicker it would probably stop almost all of my recent flats.

Anyone know of any different sealant I could try?

Sorry for the thread hijack, but I pinched flatted a Ground Control Grid at the weekend, I think the front flicked something up that I hit going pretty quick so was no surprise that it went down.

Anyway, whats the best way to repair the hole on the bead, stitch it with dental floss and some superglue?

To follow up on my own post, after a quick google, it would appear that there is some sealant that doesnt use latex, called fenwick airtight, that reckons it can seal holes caused by objects up to 6mm diameter.

So have ordered a bottle of that, and will try that out instead of the stans stuff.

Tbh, a standard snake skin tyre with the super gravity bead insert would be just right for me.

I run ghetto tubeless (currently) with a 2.5 Minion EXO and not having pinch flat or burping problems (just jinxed myself?) but then I run 30psi in it on he front and 35-40 in the rear on a Folding Nobby Nick. That’s mainly as I hate to feel the tyres rollover/fold and am happy to except the reduced grip in exchange for peace of mind and set my suspension up taking this into account.

I still run 30psi with DH tyres for the same reason. I mainly switched to tubeless to reduce hawthorn/gorse punctures and pinch flats on rocky trails and this has done the trick.

Tom KP

From the OP description, i think the issue is more about the tyre being pulled off the bead seat than leakage through hole in tyre sidewall?

Correct. Whilst I have previously pinched at the sidewall (which are a PITA and basically never seal), this is not the current issue.

I’m becoming Procurious. I do think the ghetto tubeless strip ought to help my issue, though. But I guess no one has tried this? I might give it a go and see.

If you dont want to buy new tyres, just adding a few layers of tape will improve the bead seat of the tyres, but even then moving up to a dual ply is a better long term option as the stronger sidewalls just don’t move about as much. Our experience is going over to WTB Tough casings has eliminated all issues with burps, pinches and blowouts and we’d had quite alot. Its been a 100% track record since the swap (he says jinxing this weekends racing).