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"run flat" DH tire idea

demo 9

demo 9

Turbo Monkey
Jan 31, 2007
5,910
46
north jersey
Ok, first off, i get a lot of flat tires, mostly pinch flats, i ride tubeless because of this. I came up with a 2 for 1 flat idea, generally a flat tire will ruin a race run, with this in mind, what are the opinions of getting a tubeless tire (with ust rims of course) and putting a tube inside it and glueing the tube valve stem to the rim the way a tubeless valve stem works, pump to 65 and seat the tubeless tire. My idea is when you pinch flat, the tube will just pop (and inflate the tubeless tire) giving you 2 chances for a flat tire, possibly saving your race run with no real weight gains. would this work?
 
bdamschen

bdamschen

Turbo Monkey
Nov 28, 2005
3,377
156
Spreckels, CA
No.

If you didn't have the tube in the tire and just ran tubeless, then you wouldn't have pinch-flatted in the first place. Any sort of puncture that would pop the tube in the first place would also have punctured the tubeless tire, so moot point there.

Just run tubeless and stans.
 
demo 9

demo 9

Turbo Monkey
Jan 31, 2007
5,910
46
north jersey
bdamschen said:
No.

If you didn't have the tube in the tire and just ran tubeless, then you wouldn't have pinch-flatted in the first place. Any sort of puncture that would pop the tube in the first place would also have punctured the tubeless tire, so moot point there.

Just run tubeless and stans.
Click to expand...
went through 7 tubeless tires this year with pinch flats, stans doesnt work a shlt for me
 
essenmeinstuff

essenmeinstuff

Chimp
Aug 11, 2009
71
0
halifax
what he said.

But I wonder if you lined the inside of the tide with a closed cell foam, so that normal inflation holds it up, and you can vary pressure for terain etc, but if you do flat, you have an "emergency" softish tire in there that will still sort of hold shape etc... maybe...
 
OB1

OB1

Monkey
Jul 17, 2006
494
1
San Diego, California, United States
demo 9 said:
Ok, first off, i get a lot of flat tires, mostly pinch flats, i ride tubeless because of this. I came up with a 2 for 1 flat idea, generally a flat tire will ruin a race run, with this in mind, what are the opinions of getting a tubeless tire (with ust rims of course) and putting a tube inside it and glueing the tube valve stem to the rim the way a tubeless valve stem works, pump to 65 and seat the tubeless tire. My idea is when you pinch flat, the tube will just pop (and inflate the tubeless tire) giving you 2 chances for a flat tire, possibly saving your race run with no real weight gains. would this work?
Click to expand...
Sounds good to me. Adds a tube to an already heavy ust tire. But I think the advantage of no flats could be easily worth it.
 
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big-ted

big-ted

Danced with A, attacked by C, fired by D.
Sep 27, 2005
1,400
47
Vancouver, BC
demo 9 said:
went through 7 tubeless tires this year with pinch flats, stans doesnt work a shlt for me
Click to expand...
Same here. I have this awesome new system called no-no-tubes. It consists of a specially designed rim strip with a toroidal profile that is actually air tight. You inflate the rim strip through the rim via a specially designed valve. The best part is it's compatible with 100% of rims out there. (Note that the rim strips are available with two versions of valve depending on your rim). Changing tyres is so much easier than with a conventional tubeless system, no mess, no fuss! I even plan on offering "heavy duty" versions of my rim strips for DH applications!


If you're interested, you can paypal me at...
 
kidwoo

kidwoo

Artisanal Tweet Curator
Aug 25, 2003
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bdamschen said:
Any sort of puncture that would pop the tube in the first place would also have punctured the tubeless tire,
Click to expand...
I don't agree. I quit running tubeless tires on my dh bike because I'd keep burping them or pinch flatting the bead. But it was definitely more rare than pinch flatting tubes. By your logic, you'd be splitting tires almost every time you get a pinch flat in a tube.......because you obviously just hit hard enough to split tube right? It just doesn't happen though. People have been pinch flatting tubes without splitting the tires forever.


Demo 9: You could probably get away with your idea without gluing the tube in. I would think that if you use a presta valve and just make sure the retention ring is really tight (and maybe even throw some latex/stans on the tube by the valve stem) you could get a pretty good seal.

Something I started doing a few years ago was using shrader tubes, pulling the valve core, and squirting stans in the tube. With this setup, I literally haven't had a flat in two years. When I change a tire, I can see pinch flats on the tube but I guess it seals up quickly having the tire as a support wall before losing all the air. I also use those high volume specialized tubes that don't deform and stretch to fit a 2.5ish tire. So the walls are thicker when inflated without being a full on heavy dh tube.
 
bdamschen

bdamschen

Turbo Monkey
Nov 28, 2005
3,377
156
Spreckels, CA
kidwoo said:
I don't agree. I quit running tubeless tires on my dh bike because I'd keep burping them or pinch flatting the bead. But it was definitely more rare than pinch flatting tubes. By your logic, you'd be splitting tires almost every time you get a pinch flat in a tube.......because you obviously just hit hard enough to split tube right? It just doesn't happen though. People have been pinch flatting tubes without splitting the tires forever.
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Actually the pinch flat and the puncture thing were two separate thoughts.

Pinch flats can be avoided by just running tubeless for the most part.

Punctures can't really be avoided by either tube or tubeless setup given a gnarly enough object going into the tire, but I'm saying that if something sharp has gone all the way through to puncture the tube then it will have already also penetrated the tire. That would make running a tube, with the backup of a sealed tubeless tire sort of a moot point since both would have a hole.

Since switching to ghetto tubeless and stans, I haven't had much of an issue with burping or at least not so much that I couldn't ride down the mountain and get to a pump. I'm also fairly certain that I'm not landing with nearly as much force as you are judging by some of your pics. :thumb:

Stans in the tube is a good idea, but hasn't that been done with various iterations of slime since like, 1992?
 
kidwoo

kidwoo

Artisanal Tweet Curator
Aug 25, 2003
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bdamschen said:
Actually the pinch flat and the puncture thing were two separate thoughts.?
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My bad. I misunderstood what you meant.

I'm also fairly certain that I'm not landing with nearly as much force as you are judging by some of your pics. :thumb:
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I don't know if you're being a smartass or not but northstar is where I do almost all of my dh riding. And I've never in my life flatted a tire landing a jump or a drop. It's rocks. You know this. Or at least you should. Just because some bigger jumps or drops seemed like a good place to pull out a camera over the years doesn't mean there's anything unusual about the way I ride. And I can guarantee you that at northstar I'm much smoother than most because I know almost every inch of that place.


Stans in the tube is a good idea, but hasn't that been done with various iterations of slime since like, 1992?
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Sure but slime isn't latex and who knows what the quality of 'slime' brand tubes is. The system I mentioned really does work though. Quite well.
 
LukeD

LukeD

Monkey
Sep 9, 2001
751
2
Massachusetts
demo 9 said:
Ok, first off, i get a lot of flat tires, mostly pinch flats, i ride tubeless because of this. I came up with a 2 for 1 flat idea, generally a flat tire will ruin a race run, with this in mind, what are the opinions of getting a tubeless tire (with ust rims of course) and putting a tube inside it and glueing the tube valve stem to the rim the way a tubeless valve stem works, pump to 65 and seat the tubeless tire. My idea is when you pinch flat, the tube will just pop (and inflate the tubeless tire) giving you 2 chances for a flat tire, possibly saving your race run with no real weight gains. would this work?
Click to expand...
look up le systeme from michelin. i highly doubt you could get your hands on it, but you could always somewhat re-create that...
 
D

davep

Turbo Monkey
Jan 7, 2005
3,276
0
seattle
demo 9 said:
went through 7 tubeless tires this year with pinch flats, stans doesnt work a shlt for me
Click to expand...
Have you tried a pump????


FYI, this (similar) concept was done (and abandoned) long ago by Michelin.


Put some air in your tires, and you will stop getting so many flats.
 
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demo 9

demo 9

Turbo Monkey
Jan 31, 2007
5,910
46
north jersey
FYI since all of you are obsessed with the idea of me riding low PSI, not the case, usually im flatting between 40 and 45. (and i wish i could run lower)
 
S

Slater

Monkey
Oct 10, 2007
378
0
I'd try riding a little smoother first.
Seems a lot easier.

Any impact large enough to slice a UST tire is going to pinch flat the tube as well every time.

And any pinch flat that does not slice the tire, but pinches the tube, nets you no gain over just running a UST tire in such a situation.

Not to mention that I've never been able to get the beads on any tire to seat 100% properly with a tube in it on an 823.
 
demo 9

demo 9

Turbo Monkey
Jan 31, 2007
5,910
46
north jersey
Slater said:
I'd try riding a little smoother first.
Seems a lot easier.

Any impact large enough to slice a UST tire is going to pinch flat the tube as well every time.

And any pinch flat that does not slice the tire, but pinches the tube, nets you no gain over just running a UST tire in such a situation.

Not to mention that I've never been able to get the beads on any tire to seat 100% properly with a tube in it on an 823.
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good points there, my idea was just that a DH tube (combined with tire) would be very hard to pinch, and even if so, than youd go back to the thickness of a normal UST tire (although the tube is still in there to help aid pinch flats)
 
big-ted

big-ted

Danced with A, attacked by C, fired by D.
Sep 27, 2005
1,400
47
Vancouver, BC
I have way fewer flats running the midweight Maxxis tubes than I did with tubeless. And I don't want to slit my wrists every time I change tyres anymore.
 
joelsman

joelsman

Turbo Monkey
Feb 1, 2002
1,369
0
B'ham
listen to kidwoo, and get some rims that are a bit soft, mtx or dt6.1, rim will bend a little before pinching the tube. mavic rims are much harder than the others. also try some different tires, intense made/makes some really heavy 4ply? tires. specialized armadilo casing tires?
wider taller higher volume tires? float over things better.

good luck
 
D

davep

Turbo Monkey
Jan 7, 2005
3,276
0
seattle
Back up two steps...

Are you actually running UST maxxis tires on 823s (or are people just assuming this)? If so, that is your problem (been widely discussed here several times), and is easily soved by running different tires with a decent sidewall(standard Maxxis, Michelin, etc).
 
jekyll991

jekyll991

Monkey
Nov 30, 2009
478
0
Belfry, KY
You could always carry a fun-noodle cut 26" long on your back. Bust a tire? Stuff that bad boy in there and ride her out. Work for the ATV/UTV people haha.
 
Acadian

Acadian

Born Again Newbie
Sep 5, 2001
714
2
Blah Blah and Blah
demo 9 said:
FYI since all of you are obsessed with the idea of me riding low PSI, not the case, usually im flatting between 40 and 45. (and i wish i could run lower)
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dayum - how can you even ride with any kind of control with that much air in your tyres? especially on the front. heck, I don't even run that much on my trail bike.
 
demo 9

demo 9

Turbo Monkey
Jan 31, 2007
5,910
46
north jersey
davep said:
Back up two steps...

Are you actually running UST maxxis tires on 823s (or are people just assuming this)? If so, that is your problem (been widely discussed here several times), and is easily soved by running different tires with a decent sidewall(standard Maxxis, Michelin, etc).
Click to expand...
I do run this, i might be blind but what is so bad, isnt this the "correct" set up? i attempted to run a tube DHF one time(as tubeless) but could not get it to work.
 
OB1

OB1

Monkey
Jul 17, 2006
494
1
San Diego, California, United States
bdamschen

bdamschen

Turbo Monkey
Nov 28, 2005
3,377
156
Spreckels, CA
kidwoo said:
I don't know if you're being a smartass or not but northstar is where I do almost all of my dh riding. And I've never in my life flatted a tire landing a jump or a drop. It's rocks. You know this. Or at least you should. Just because some bigger jumps or drops seemed like a good place to pull out a camera over the years doesn't mean there's anything unusual about the way I ride. And I can guarantee you that at northstar I'm much smoother than most because I know almost every inch of that place.
.
Click to expand...
Heh, sorry dude- Wasn't meaning to imply that you're not smooth or a hucker. I just usually equate faster riders with more stress on the bike.

And yeah, most of my "will it hold?" testing ends up happening the first weekend of the season that I get to northstar.


Oh- and to add something to the thread for the OP: I've never ridden a UST dh tire tubeless before, I usually just run a regular DH tube tire like a high roller and use a little bit of stans to get it to seal up nice to the rim although lately I'm really liking my ghetto tubeless setup.

I weigh about 200 lbs, run between 35 and 40 psi in my tires, ocassionaly screw up in the rocks and don't clear the jagged one that I mean to and break a spoke or something and like to run my suspension stiff. I don't think I'm a slow rider or anything.

Where are you riding?
 
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kidwoo

kidwoo

Artisanal Tweet Curator
Aug 25, 2003
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demo 9 said:
I do run this, i might be blind but what is so bad, isnt this the "correct" set up? i attempted to run a tube DHF one time(as tubeless) but could not get it to work.
Click to expand...
Try again you might get it to work. I run tubeless on my 7" bike with a 60d rear 2.5 minion and a 3c 2.5 minion on 823s and it works really well. Also.....get away from stans if you can. I use molding latex and dilute it with water for something way thicker than stans. It helps the initial seal as well as actually plugging holes in your tire (which stans seems to rarely actually accomplish).
 
kidwoo

kidwoo

Artisanal Tweet Curator
Aug 25, 2003
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bdamschen said:
Got a set ratio you use for the latex?
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I usually dump two scoops in a gatorade bottle and add maybe........enough water to fill a 32 ozzer halfway?

I don't measure it out, I usually just add water until it's the consistency I want. I mean honestly, anything thicker than stans will work better.

OB1: The dilution I use is WAY thicker than stans. But yeah that's pretty much all stans is, plus ammonia. But I got tired of watching that shlt squirt out of a small hole in a tire and just not seal. Using the thicker stuff, you can just wait 5 minutes and pump your tire back up. When I get in on my hands changing tires, it dries so much quicker, it leaves a film on my hands almost immediately (IE is a much quicker sealant).

Dave: I quit buying the porn stuff. Acadian hooked me up with some modeling latex that I couldn't find around here. The jug he sent me is so thick that I think one tub should last your bike career. I've gone through maybe a quarter of it in two years, running tubeless on two bikes.
 
D

davep

Turbo Monkey
Jan 7, 2005
3,276
0
seattle
To answer your question about UST maxxis tires and 823s:

823s are VERY hard rims in both design and material. The sidewalls are straight, thick, and made with Mavic's super hard maxtal aluminum (this has a lot to do why these rims tend to last.

The UST maxxis tires use a completely different (read softer, weaker) carcas construction than the non-tubeless versions. Folding bead, fewer TPI reinforcement, and no butyl pinch flat insert.

Combine these two (very hard sidewall rim and sissy sidewalled tire), and you end up with tires that have sidewall cuts (pinch flats).

I have not run a tube going on 6 years. I have never specifically purchased a UST tire (except mich as that is the only way they come). Single and double ply maxxis or michelin tires mount and seal fine on 721, 729, 823, 5.1 ...at least that has been my experience.
 
D

davep

Turbo Monkey
Jan 7, 2005
3,276
0
seattle
kidwoo said:
Dave: I quit buying the porn stuff. Acadian hooked me up with some modeling latex that I couldn't find around here. The jug he sent me is so thick that I think one tub should last your bike career. I've gone through maybe a quarter of it in two years, running tubeless on two bikes.
Click to expand...

Brand??


Have you ever tried to emulate the 'kitty hair' that is in stans. I don't know what it is, but it certainly sinks to the bottom of the quarts (need to constantly shake them to keep the particles in suspension). If I just pour the stans off the top without shaking, it does not work nearly as well IMO. It makes a lot of sense to include some sort of material/matrix to form the 'clot'.


Carpet fuzz?? roadie leg hair?? landing strip trimmings??? chopped fiberglass??
 
DickusCheezus

DickusCheezus

Chimp
Oct 23, 2009
73
0
Hillsboro
I worked for a company that sold tire balls. They are a pain in the a#@ to install, the price is high and the weight is a bit on the heavier side they allow for multiple flats and you'll never get a flat tire.

Check them out:
http://www.tireballs.com/flash/tests.html

I wouldn't personally run them in a bike, maybe an enduro moto, but that's about it.
 
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