Burping tyres

[Tubby G]

Now then … I’ve burped two tyres to flat recently on the rear of my full fat. 27.5” with a 32mm rim running 2.4 tyres

It’s a fairly new wheel, Nukeproof Neutron wheelset, bought after destroying the original wheel on a rocky drop

I’m not using the full fat much as I’ve got a lightweight now too, but still want to solve the burping issue

I’ve inspected the rim thoroughly and can’t see any obvious dents or dings. Don’t know whether to buy a new tyre or re-seat the well used Minion SS I’ve just burped to flat and couldn’t re-seat out on the trail

Do I need more pressure in the tyre ? Currently have it at 24psi. I am trying to ‘schralpe’ berms, and this is how I burped it to flat at the weekend.

 

[Growmac]

Two obvious options: put a tyre insert in to hold the sidewall up under pressure, or maybe don't deliberately wreck the trails by trying to ‘schralpe’ berms and it won't be a problem.

 

[Tubby G]

Two obvious options: put a tyre insert in to hold the sidewall up under pressure, or maybe don't deliberately wreck the trails by trying to ‘schralpe’ berms and it won't be a problem.

ok I probably used the wrong term by schralping, I’m not deliberately trying to wreck the berm, just learning to get more confident by hitting the berm at speed and pumping into the turn to find the grip and let the berm catch the tyre, which makes a small ‘schralpe’ sound

I thought about an insert, but being naturally tight, and only using the full fat as a reserve bike, a little reluctant to spend more cash if I simply need a better tyre with stronger sidewalls or more psi

 

[RustyIron]

Do I need more pressure in the tyre ? Currently have it at 24psi.

Yes. More pressure is what you need.

Most tire pressure gauges are notoriously cheap import trash. When you contaminate them by using them on tires that contain sealant, they get even worse. You might be running 24psi, or maybe not. Use the gauge to obtain consistency and repeatability, but don't think that the numbers are meaningful.

If 24 is getting you burps, bump it up to 28 and see what happens. You might discover that the higher pressure will keep your tire from deforming side-to-side, allowing you to more accurately hold a line.

 

[Gary]

Do I need more pressure in the tyre ? Currently have it at 24psi.

YES.
Much more pressure. A Minion SS will only be an EXO casing only 2.3" in volume.
I generally run 40psi but a minimum of 38psi rear on an SS at 200lb

"Scralping" by running excessively low pressures is pretty lame.
the SS is a great tyre for drifting so instead of practicing lame little scralps learn to control the rear tyre's drift and regain traction again using the edge knobs with the tyre at a decent pressure.

 

[JP-NZ]

You need a lot more pressure, increase pressure till you don't burp tyres. Also to be technically correct your not "burping" from 24psi to single digits you definitely are pushing too hard more a case of trying to destroy the rim and tyre.

From memory (forgive me if I'm wrong) but seem to remember you posting about being a bit heavier (maybe its in the name?) but if your over 200lbs at least 30-34 psi is needed if heavier than that even 34-38psi.

 

[KnollyBro]

ok I probably used the wrong term by schralping, I’m not deliberately trying to wreck the berm, just learning to get more confident by hitting the berm at speed and pumping into the turn to find the grip and let the berm catch the tyre, which makes a small ‘schralpe’ sound

I thought about an insert, but being naturally tight, and only using the full fat as a reserve bike, a little reluctant to spend more cash if I simply need a better tyre with stronger sidewalls or more psi

First off, I think its great that you have an Instagram channel to post your ride edits. It looks like you really enjoy riding your bike and making videos! As for learning new techniques, watching a Youtube video can only help so much as you will have to find out what works for you either by trial and error or by taking a lesson. IMHO, spend more cash and put an insert in your rear tire as anyone who rides around with 34-38 PSI must be a masochist.

 

[Tubby G]

YES.
Much more pressure. A Minion SS will only be an EXO casing only 2.3" in volume.
I generally run 40psi but a minimum of 38psi rear on an SS at 200lb

"Scralping" by running excessively low pressures is pretty lame.
the SS is a great tyre for drifting so instead of practicing lame little scralps learn to control the rear tyre's drift and regain traction again using the edge knobs with the tyre at a decent pressure.

they are quite lame, and quite easy to engage, but fun, until the tyre came off the rim!

I’m always tying out different pressures, and usually run around 28-30psi on the rear, but this SS is so well worn the centre tread is virtually bald so I had it at a lower pressure in the hope of finding a little grip!

 

[Tubby G]

You need a lot more pressure, increase pressure till you don't burp tyres. Also to be technically correct your not "burping" from 24psi to single digits you definitely are pushing too hard more a case of trying to destroy the rim and tyre.

From memory (forgive me if I'm wrong) but seem to remember you posting about being a bit heavier (maybe its in the name?) but if your over 200lbs at least 30-34 psi is needed if heavier than that even 34-38psi.

I am indeed a heavy guy and over 200 lbs so will re-seat it and try it again at a higher pressure

 

[Growmac]

YES.
Much more pressure. A Minion SS will only be an EXO casing only 2.3" in volume.
I generally run 40psi but a minimum of 38psi rear on an SS at 200lb

40 psi??? Seriously? That's completely bonkers. Why don't you just get rid of the tyre and replace it with a wooden band like they do on horse drawn carriages? That might at least have some conformity. That must feel absolutely hideous and have no grip at all?

Minion SS comes in Exo+ btw, that's what I run on my NA bike in the summer (at 22 psi with a Rimpact). I'm 80 kg.

 

[urastus]

Why not consider a bigger tyre, like 2.6 high volume? A dhf or dhrII. I only ever buy them on sales - $38 (au) here now for a dual compound dhf 27.5 x 2.6. I recommend maxterra though, I think they actually last longer.

I'm currently running a 2.8 rear that I got for nothing. It has about an 8mm cut in the centre of the tread. I patched it inside and because I run a tannus on the rear it's fine. It's a dhr; I've gone down 1psi from the 2.6 I had, but it still feels firmer. That's 18psi in the 2.8, 19psi in the 2.6. I'm playing on jumps and drops - I'm about 190lb with pack / gear.

 

[Tubby G]

Why not consider a bigger tyre, like 2.6 high volume? A dhf or dhrII. I only ever buy them on sales - $38 here now for a dual compound dhf 27.5 x 2.6.

The bike came with a 2.8 DHR II - didn’t like it at all, felt like riding a tractor

Temporarily put a 2.6 on instead, still felt too wide, so went with the Minion SS last summer and was far happier with it. I took that off and changed it to a 2.4 Nobby Nic when the trails turned sloppy. It’s the Nobby Nic that I first burped to flat a few weeks ago. Took that off and put the well used SS back on. It’s been fine all bank holiday weekend riding simple XC, but on Saturday went for a blast around our local trail centre and that’s when it went flat again after hitting some berms

When I posted this thread last night, I was about to reluctantly buy another tyre, as I was thinking it was perhaps the fact I’d re-fitted an old tubeless tyre and it hadn’t seated to the rim properly, or it just needs more psi. I’ll fit it again today and try it out pushing the berms at speed at a higher pressure, on some trails where the car isn’t too far away! If it comes off again, new tyre

 

[Mikerb]

Running a higher pressure seems the obvious solution but also note that a freshly fitted tubeless tyre is more prone to burping until it has covered a few miles and fully settled/sealed. Again running a higher pressure than normal for one good ride after fitting a tyre is a good insurance policy

 

[Tubby G]

Well I’ve re-fitted the Minion SS, it appears the tyre is actually warped

Rim is fine, running true. Spinning the wheel with the tyre fitted and you can see the actual rubber is warped & wobbly. Very strange. I wonder what caused that?

I’ll leave it on for now and see how it rides at the weekend, just for fun, but ordered a 2.35 Hans Dampf in SuperGravity as they’re a bargain on Merlin’s site. Silver logo, different brand to my Maxxis DHF up front, yellow logo

 

[Growmac]

Maxxis tyres are great but the casing is very prone to stretching. I ruined both my Maxxis tyres putting them onto the very tight and sticky Bontrager carbon rims on my new Rail. They feel fine riding off road, but the rear tyre especially is comically wobbly.

 

[2WheelsNot4]

Doesn't happen with inner tubes

 

[Tubby G]

Doesn't happen with inner tubes

The Yorkshire thorns around our way are tough little b*st*rds and a tubed tyre doesn’t last an hour unfortunately

 

[Growmac]

Doesn't happen with inner tubes

I know, but I've not had a ride interrupted by a puncture in 2 years, whereas I used to get 2-3 a month around here. For me it's well worth the slight hassle between rides.

 

[Gary]

40 psi??? Seriously? That's completely bonkers. Why don't you just get rid of the tyre and replace it with a wooden band like they do on horse drawn carriages? That might at least have some conformity. That must feel absolutely hideous and have no grip at all?.

Minion SS comes in Exo+ btw, that's what I run on my NA bike in the summer (at 22 psi with a Rimpact). I'm 80 kg.

and ride like an old woman presumably.

An SS needs sidewall support to work properly.
If you don't understand why an SS *NEEDS* support. You don't understand how to get the best performance from one.
The whole point of running one should be to gain straight line speed and low rolling resistance. Not straight-line grip. (who needs that anyway? ). And to achieve it you need a high enough pressure that the side knobs aren't dragging along the whole time. It also needs good sidewall support for the side knobs to bite and allow you to lean the bike over predictably through the drift zone to the actual edge. Which when in use rails turns exactly like a DHF.

EXO + is just a single ply casing and offers no real support o it's own.
A high quality insert such as cushcore may help partially stiffen those flimsy sidewalls but certainly not enough for 22psi to allow it to work in the way I've described.

Ive been running Maxxis SS and previously to that Bling Blings for over 20 years so please don't try to tell me I'm doing it wrong!

I'm 95kg just now. But I still rode them around 40psi when 10kg less and riding considerably faster.

 

[Gary]

Maxxis tyres are great but the casing is very prone to stretching. I ruined both my Maxxis tyres putting them onto the very tight and sticky Bontrager carbon rims on my new Rail. They feel fine riding off road, but the rear tyre especially is comically wobbly.

29" perchance?

 

[dobbyhasfriends]

for me the pressure change did the trick, Gary is right about that.

but that is when running schwalbe with super gravity casing, they seem to have far flexier sidewalls than the maxxis with DH casing AND the michelin wilds I was using, I could run far lower pressure without any burping.

right now ive settled on

28/32 F/R
on the maxxis & michelin it was
24/28 F/R

had this discussion RE: tyre pressures with zimmer and Gary a while back and decided to up my pressure, it took a bit of getting used to but no more burping and a more direct feel to the trail. it also made me ride differently and I had to adjust my suspension to suit, I also move the bike around and over things more rather than plowing them down.
I wish I could use a lighter sidewall but im not good enough considering the terrain I usually ride

 

[Tubby G]

for me the pressure change did the trick, Gary is right about that.

but that is when running schwalbe with super gravity casing, they seem to have far flexier sidewalls than the maxxis with DH casing AND the michelin wilds I was using, I could run far lower pressure without any burping.

right now ive settled on

28/32 F/R
on the maxxis & michelin it was
24/28 F/R

had this discussion RE: tyre pressures with zimmer and Gary a while back and decided to up my pressure, it took a bit of getting used to but no more burping and a more direct feel to the trail. it also made me ride differently and I had to adjust my suspension to suit, I also move the bike around and over things more rather than plowing them down.
I wish I could use a lighter sidewall but im not good enough considering the terrain I usually ride

I’m always playing around with psi, different tyres, different psi, different conditions, change the psi, different terrain, you guessed it, I change the psi

on my Rise with Dissector / DHR II I seem to have settled on around 24/28

on the full fat with DHF / SS I was running them higher, 26/30, the full fat is a 26kg tank. I only had the Minion SS lower at the weekend as it’s so worn I thought it might give me a chance of finding some grip

Anyway, I’ve just checked the warped & wobbly SS I fitted earlier and it’s lost a load of psi already. A bit of soapy water reveals it’s losing air on the bead, both sides, so it’s coming off as soon as the Hans Dampf arrives

 

[JP-NZ]

Well I’ve re-fitted the Minion SS, it appears the tyre is actually warped

Rim is fine, running true. Spinning the wheel with the tyre fitted and you can see the actual rubber is warped & wobbly. Very strange. I wonder what caused that?

Maxxis tyres have been through a lot of bad batches over the last 12 months. You can see its out of alignment as soon as you spin the rim with the tyre attached.

DHF/Assegais were the worst in 29" from memory, if you fit a new tyre up and it wobbles return it Maxxis are well aware of the manufacturing issues

 

[Tubby G]

Maxxis tyres have been through a lot of bad batches over the last 12 months. You can see its out of alignment as soon as you spin the rim with the tyre attached.

DHF/Assegais were the worst in 29" from memory, if you fit a new tyre up and it wobbles return it Maxxis are well aware of the manufacturing issues

it’s not a new tyre unfortunately, an old one being re-used. It wasn’t warped prior to last weekend though so guessing I’ve somehow stretched the rubber when riding, if that’s even possible!

 

[JP-NZ]

it’s not a new tyre unfortunately, an old one being re-used. It wasn’t warped prior to last weekend though so guessing I’ve somehow stretched the rubber when riding, if that’s even possible!

If you've burped a tyre so hard its come off the rim then yes very possible

 

[Gary]

Anyway, I’ve just checked the warped & wobbly SS I fitted earlier and it’s lost a load of psi already. A bit of soapy water reveals it’s losing air on the bead, both sides, so it’s coming off

Running silly low pressures and actively trying to rip the bead off the rim in am attempt to mimick the "cool" noises you've watched on Instagram etc. can have a habit of doing that to your tyres casing/bead.

 

[Gary]

Maxxis tyres have been through a lot of bad batches over the last 12 months. You can see its out of alignment as soon as you spin the rim with the tyre attached.

DHF/Assegais were the worst in 29" from memory, if you fit a new tyre up and it wobbles return it Maxxis are well aware of the manufacturing issues

It's been happening a lot longer than that. 29" are terrible for it. Seen far fewer 27.5s do it and absolutely no 26"... Its almost as if a bigger tyre needs to be constructed to be tougher and stronger and heavier to be used in the same way as a smaller diameter one and actually survive ... Who'd a thunk, eh?

 

[Pezzar]

The only Minion I had was a wobbler too.
Tbf I'm 95kg on a full fat Marin and I've been riding 22/24 on the new Vee tyres (HOL attack front 2.4 and crown gem 2.6 rear) on Marin own rims (without looking 35mm?).
I mean I don't 'schralp' but I be been pushing them hard as I get used to the bike, experimented with higher pressures (26/28) and it felt bloody vile, like I was on wooden hoops.
Obviously every tyre, wheelset, rider is different but not a chance I'll go much above another 2 or 3 psi on these tyres. No inserts either. Bloody great tyres tbf.

 

[Gary]

You do realise tyre volume, casing riding style and rider weight make a massive difference to how pressures translate?
Wildy stating pressures you do or don't like without all of that info is an entirely futile exercise.

 

[Tubby G]

Running silly low pressures and actively trying to rip the bead off the rim in am attempt to mimick the "cool" noises you've watched on Instagram etc. can have a habit of doing that to your tyres casing/bead.

Do you really think I was trying to rip the tyre off the bead just to make a cool noise, when we were around 10 miles from the car with no track pump out on the trail ? You do come out with some odd sentences sometimes Gary