Tubliss High Pressure Bladder Leak-down Rate & Filling in the Boonies

Discussion in 'Thumpers' started by motobene, May 27, 2019.

  1. motobene

    motobene Motoing for 51 years Supporter

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    Curious. In which way do you mean 'cutting?'
  2. joelee

    joelee Been here awhile Supporter

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    Tubliss is new to me, just tried to remove my front tire from the rim with Tubliss and it was hard, more so than with tubes, would be tough in the field for sure! can't get the tire in drop zone of rim
  3. motobene

    motobene Motoing for 51 years Supporter

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    Yeah the fronts are a bit tough, but once you get Tubliss installed it's tough and reliable.

    Concerning the original thread title regarding leak-down, over many months I've been impressed with it being slower than expected.

    And something that has helped is pumping my bicycle pump up to 100 or so psi before putting on the air chuck. Little air loss that way when topping off.
  4. Hankus

    Hankus Been here awhile

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    Some tires are easier to mount and dismount using Tubliss. Its part of why I went away from the Shinko on the front of my bike. Just too hard to get on and off. I found The Bridgestone much easier to mount and it sealed right up first try with no drama.

    OTOH, I did ride the Shinko dead flat and didn’t know it til I got back home. I don’t know if looser tires will do that or not.
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  5. renogeorge

    renogeorge Let's ride!! Supporter

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    Don’t know why you are having trouble. Just as with tubes, the key is keeping the away side bead down in the drop center of the wheel as you work your iron across from that spot. When removing liner, same thing and pinch walls of liner together to make it easier to remove install. Should barely need irons. FWIW
  6. joelee

    joelee Been here awhile Supporter

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    Found one of my errors. Started across from rim lock, should have started closer to rim lock so I could keep opposite side in drop center. I know this. Was in a hurry and tired. Haven’t given up on it, really like the concept of Tubliss. Haven’t given up on them
  7. motobene

    motobene Motoing for 51 years Supporter

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    Don't. They are good. Once you figure out the quirks and tricks they are very manageable. Tires are part of the suspension. Being able to run lower pressures (without de-brading issues) really improves the ride and traction in the slick stuff.

    One front I did I got crossed up on the liner with a tire tool and damaged it a bit. That one did seal to the inside of the tire, but only after I squozed in my usual Quadboss sealer into the low-pressure side. I've never put sealer in the high pressure tubes. I wonder if sealer would slow down the leak-down rate a touch?
  8. Anders-

    Anders- 690R

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    If only folks cared as much about regular suspension tuning as running tubliss with very low tire pressures :lol3

    Edit: my ranting point being that it’s easy to overlook suspension and just hit lower pressures regardless of the problem one is trying to remedy.
  9. renogeorge

    renogeorge Let's ride!! Supporter

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    Some truth to that. But while I do find the lower pressures to be a positive part of my suspension setup, there are other significant benefits-traction, on the bike plugging of most flats, no pinch flats even at very low pressure, much better run flat capability......
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  10. timeOday

    timeOday Long timer

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    Trying a lower pressure is free, and putting Tubliss on a wheel is $100. "Sending my forks to my suspension guy" in the hopes of getting them back with the mythical Small Bump Compliance costs hundreds.

    But besides which, what is the unsprung weight in play when a tire absorbs a 1" stone? None! That's unbeatable.
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  11. Anders-

    Anders- 690R

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    Agree that price is a part of the equation, another one being how easy the approach is; high pressure - bad, low pressure good.
    In comparison, suspension is black magic :lol3


    Edit: no more thread derailing from me, have a good friday evening folks!
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  12. timeOday

    timeOday Long timer

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    Since you're being reasonable, I can admit that Tubliss may be somewhat compensating for my AER forks...

    Have a happy weekend in Швеция
  13. motobene

    motobene Motoing for 51 years Supporter

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    When I was thinking BYOB Beta, I checked out all sorts of suspension options. Glad I stuck with the stock 2019 Sachs suspension. Really like the suspension. I run it more open and free... less preload on the rear spring. Then again the years of trials make my preferences somewhat weird.

    When I did Tubliss it was the cherry on top. Guys that throw a leg over say, 'wow, nice suspension.'

    So yeah maybe lower pressure does help ignore other problems, but I'll take whatever niceness I can get, no matter where from.
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  14. joelee

    joelee Been here awhile Supporter

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    Just got back from a sloppy wet ride, rain on and off, that rear tubliss hooked up so good, tractor right up those hills. Worried that I damaged my front tire putting it back on but when its worn will put tubeless back on front. will not take long, fallen in love with my new KTM 500 so will be on it often
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  15. motobene

    motobene Motoing for 51 years Supporter

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    The Beta and its Tubliss tires has been sitting all winter. Off and on I air the Tubliss back up.

    I'm finding the leak-down rate to be less than I earlier assumed. I think I was loosing a lot of psi by having the inner tube pressurize the bicycle pump. I changed a while back to pressurizing the the pump to about 100 psi before putting the air chuck on.

    So how much did I really lose from leak-down over, say, a month? Hard to know. What I do know is I was losing pressure fiddling with Chuck's.

    Leaving a pressure gauge on long term and doing pressure versus time would be the only way to know what the precise leak rate is.

    Today I put yet another Tubliss system on a bike, this time a 33-year-old vintage trials bike with steel rims. I could not stop the tire from moving on that slick chrome rim! So I converted it to Tubliss. I had to run 25 psi in a 2-day event to make sure I didn't rip the valve stem out. That sucked given the pressure should have been no more than 5 psi for trials competition.
  16. Stephen

    Stephen Long timer Supporter

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    First things first: thank you, @motobene and all who have contributed to this thread. I'm glad search turned it up. I've read a lot of it and I've learned a lot.

    I've been using a Zefal Twin Graph bicycle tire gauge with a dial to check pressure. With proper technique, air loss from a check is not measurable. So that part works.
    It takes two weeks of sitting to go from 110 to 95 psi. So that part works pretty well.
    It took a few months for my new Dunlops to go from 25 to 22 psi. So that part is outstanding.

    For the most part, my experience tracks what the rest of y'all who like Tubliss have found:
    - Fronts are fun!
    - Get plenty of wheel weights!
    - Run lower psi than before!

    Context:
    2016 KTM 690 Enduro, so I'm in the @renogeorge world, except I've only put a few hundred miles on the Tubliss and that's mostly pavement with some unpaved county roads. The future holds long pavement rides to reach much worse and varied unpaved two-track.
    I installed Tubliss when I put on the new Mission tires. Some the best street tires I've had in 50 years of riding. Not the best dual-sport tires, surely, but plenty good enough for dry unpavement. These tires are stout. I keep running them at lower and lower pressures, and they keep responding by working better. Unlike my street-raised buddies, I actually air down for longer unpaved stretches--and I have fun while they struggle. The Tubliss/Mission combo serves me very well for this. In cool wx, I have ridden back on pavement without bothering to air back up, and it's been fine.
    Factory spec is 26psi pavement, 22 psi off. I'm now running 24, dropping to 20 off, and it works better. As temps go up here in Texas, I'll likely go back up. Heat failure is real, but a lot less likely absent a tube. If I remember, I'll grab my IR thermometer and check sidewall temps next time. Big if.

    Y'all can probably tell that motobene's batshit-loony check-everything approach seems quite normal to me.
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  17. motobene

    motobene Motoing for 51 years Supporter

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    Stephen, my fellow bat-shit-looney friend, thanks. All I care about is for the diligence in checking things out to help someone.

    Thanks for your feedback as well an the gage and other bits!

    It's remarkable how bike weight affects the right pressure for circumstances. 20 seems about right off road on a really heavy bike. My Beta 390 likes 10 front and rear....
  18. Gaup

    Gaup Adventurer

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    If you have nitrogen at disposal fill the high pressure tube with that, nitrogen have a bigger molecule so its leaking a lot slower..
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  19. motobene

    motobene Motoing for 51 years Supporter

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    I do, for recharging shocks, but I never bothered because air is 78% nitrogen. But yes, trading the 22% of oxygen and trace gases for 100% nitrogen would help... a little.
  20. Stephen

    Stephen Long timer Supporter

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    In the past, I have used nitrogen concentrators in my tires--the previously mentioned Michelin natural rubber tubes do it well, as do my tubeless Dunlops. Fill with the Special Atmospheric Blend; the CO2 bleeds out faster than the N2; top up.. repeat. :lol3

    When I first installed the Tubliss, I lacked a compressor that would go over 95 psi, so filled from the 5 lb bottle of CO2 that I carried in the sidecar. Leaks down fast, very fast, and as it did I replaced with atmosphere from my new compressor. Now it holds pressure for weeks. So, yes, nitrogen is empirically better than CO2 or atmosphere.

    I originally chased this thread down [that sounds funny..] to find out what folks who actually ride with Tubliss carry with them 1. to air up after dirt sections and 2. to maintain the high pressure side over a period of days, routinely or when things go awry. Not sure I've found a clear answer. I'm also not terribly worried about finding an optimal solution since these Dunlops feel like they'd work fine at 0 psi.