Results 1 to 10 of 10

Thread: Tubes or UST

  1. #1
    mtbr member
    Reputation:
    Join Date
    Nov 2004
    Posts
    272

    Tubes or UST

    I need a new set of wheels for my 5 Spot and was really thinking of going with Hadley's on DT 5.1's.

    I am currently on 819's but have been burping some tires here and there so I want to get a wider rim.

    Keep in mind I am a big boy who punishes most bike parts.

    Should I go back to tubes??????????

  2. #2
    mtbr member
    Reputation: Clyde S Dale's Avatar
    Join Date
    Jan 2005
    Posts
    1,143
    Quote Originally Posted by TXDirtDawg
    Keep in mind I am a big boy who punishes most bike parts.

    Should I go back to tubes??????????
    If you go back to tubes you'll have a much better selection of tires. The Hadley/DT 5.1 combo would be good. There's also a tubless conversion kit for the DTs so you could go both ways. I'm currently running 819's myself and I've been happy with them, but I've been dissapointed at the slow rate of new releases in UST tires.

    As my screen name suggests I'm a big boy, too. Currently about 220 geared up. The few times I've burped air there have always been the same set of circumstances: newly mounted tires; pressures too low (~30psi); and grabbing a lot of front brake while turning sharply after rolling something.

    If I keep my front around 33psi and the rear around 35 I get the performance and reliability I need. I'm currently on the Kenda BG/Nev 2.1 and I'm mostly liking it. I run Stan's as well and haven't stopped to change a flat since I last ran tubes back in '04. Here's a recent pic of my tires getting squished.
    Attached Images Attached Images


  3. #3
    mtbr member
    Reputation:
    Join Date
    Apr 2005
    Posts
    55
    Stay tubeless. On 819's and X3.1's I've had no problems atall running UST tyres with latex inside (I use the Eclipse kit but they now sell large bottles of art latex pretty cheaply). 1 puncture in 3 years rather than 3 punctures each ride so far, and the one I had was a 2" rip in the sidewall.

    Most popular tyres can be had UST. I also run non-UST tyres tubeless with the Eclipse stuff (like Stans), and they work fine too but lose pressure a bit more quickly.

  4. #4
    MK_
    MK_ is offline
    carpe maņana
    Reputation: MK_'s Avatar
    Join Date
    Nov 2004
    Posts
    7,132
    The biggest advantage with tubes is that the flat isn't instant. I've been riding some steep terrain with my buddies and on particular flat stayed in my mind. Right after a big step down, the front tire burped a lot air, it was a 2.5 Nevegal, big air volume, it looked like the front just gave out under my buddy and he endoed pretty severely. With a tube, you puncture, and you have time to stop before you're flat. It is a big safty thing. There are a bunch of other reasons, but they have all been covered.

    If you go with tubes, do youself a favor and get a tire with a sidewall that's at least as strong as the one on Fat Alberts. I'm running 2.4 Noby Nics right now and it is a pinch flat nightmare. I had none for months and months with Fat Alberts running welterweight Maxxis tubes.

    _MK
    .
    "No man goes before his time -- unless the boss leaves early."
    -- Marx, Groucho

  5. #5
    mtbr member
    Reputation: Clyde S Dale's Avatar
    Join Date
    Jan 2005
    Posts
    1,143
    Quote Originally Posted by MK_
    The biggest advantage with tubes is that the flat isn't instant. I've been riding some steep terrain with my buddies and on particular flat stayed in my mind. Right after a big step down, the front tire burped a lot air, it was a 2.5 Nevegal, big air volume, it looked like the front just gave out under my buddy and he endoed pretty severely.
    You bring up a point I forgot to mention in my first post. Every time I've burped air (and its only been a handful of times) its been at the front.

    With your friend's Nev 2.5 it sounds like it was a tubed tire run tubeless, right? I wonder if non-UST tires run tubeless are more susceptible to burping air?


  6. #6
    MK_
    MK_ is offline
    carpe maņana
    Reputation: MK_'s Avatar
    Join Date
    Nov 2004
    Posts
    7,132
    Quote Originally Posted by Clyde S Dale
    You bring up a point I forgot to mention in my first post. Every time I've burped air (and its only been a handful of times) its been at the front.

    With your friend's Nev 2.5 it sounds like it was a tubed tire run tubeless, right? I wonder if non-UST tires run tubeless are more susceptible to burping air?
    Yeah, it was standard mounted tubless. Kenda's ultra thin sidewalls make them pretty unreliable tires to be mounted tubless to boot.

    _MK
    .
    "No man goes before his time -- unless the boss leaves early."
    -- Marx, Groucho

  7. #7
    mtbr member
    Reputation:
    Join Date
    Nov 2004
    Posts
    381

    Why tubeless if you need high pressure to prevent burps?

    Quote Originally Posted by Clyde S Dale
    newly mounted tires; pressures too low (~30psi); and grabbing a lot of front brake while turning sharply after rolling something.

    If I keep my front around 33psi and the rear around 35 I get the performance and reliability I need. I'm currently on the Kenda BG/Nev 2.1 and I'm mostly liking it. I run Stan's as well and haven't stopped to change a flat since I last ran tubes back in '04. Here's a recent pic of my tires getting squished.
    Can someone answer a question for me? I thought the point of tubeless was to allow people to run lower tire pressures, and in theory lower rolling resistance. I'm around 190 with gear and typically run my tires around 30-35psi WITH TUBES. Do you really have to run 35psi+ on tubeless to keep them from burping? If so, I fail to see any benefits to the tubless movement.
    MCM #269

    "Lightweight , durable , inexpensive
    Pick 2."

  8. #8
    mtbr member
    Reputation:
    Join Date
    Mar 2004
    Posts
    75
    Quote Originally Posted by BikeLust
    Can someone answer a question for me? I thought the point of tubeless was to allow people to run lower tire pressures, and in theory lower rolling resistance. I'm around 190 with gear and typically run my tires around 30-35psi WITH TUBES. Do you really have to run 35psi+ on tubeless to keep them from burping? If so, I fail to see any benefits to the tubless movement.
    I think it all depends on your situation and what your setup is. By running tubeless you can run lower pressures for better traction and lower rolling resistance and avoid pinch flatting since there is no tube. The "burping* issue is a side-affect of this, again, depending on what you are running.

    The Stan's setup with rim strips is suppose to be really good at sealing up and preventing burping. There is a good demo video on their site. However, it depends on what kind of tire you are running since some tire brands have thinner side walls than others. The thinner side-walled tires may need a little more air pressure to keep them sturdy.
    The benefits are that any puntures will seal up and it is possible to run lower air pressure.

    You can run the Stan's sealant on UST rims without rim strips (since the rim is sealed). However, since you aren't running the rim strips some tires may not seal as well and may require more air pressure to prevent burping. The benefit of this system is, again, you aren't running tubes that could pinch flat and you have the sealant to fill any punctures.

    Or you can run UST rims and tires. You can get away with running lower pressures with this setup because the tire side walls are much stiffer. The disadvantage of this setup is that the tires are heavier and the price per tire is higher.

    I'm sure there are other combos and benefits and disadvantages but that's a quick run down.
    Last edited by wArden; 06-01-2006 at 01:44 PM.

  9. #9
    mtbr member
    Reputation: Clyde S Dale's Avatar
    Join Date
    Jan 2005
    Posts
    1,143
    Quote Originally Posted by BikeLust
    Can someone answer a question for me? I thought the point of tubeless was to allow people to run lower tire pressures, and in theory lower rolling resistance. I'm around 190 with gear and typically run my tires around 30-35psi WITH TUBES. Do you really have to run 35psi+ on tubeless to keep them from burping? If so, I fail to see any benefits to the tubless movement.
    I won't pretend to give a definitive answer, but:

    1. I wouldn't characterize 35psi as high pressure.

    2. I never wrote that I needed 35psi+ to keep the tires from burping. I've only burped the fronts under certain circumstances specified above when pressures were down around 30psi. 33-35psi is what works for me with the tires I run on the terrain I ride.

    3. Assuming one can make the equivalence, your 30psi at 190lbs of body weight translates to 34.7lbs at my 220lbs of weight. Proportionately that makes my front pressure lower than yours and my rear about the same. Look at my rear tire in the picture I posted. That's a pretty simply, low-key roll. The rear tire is conforming to the trail pretty well and the front is giving me a pretty big contact patch.

    4. The benefits of UST are not just the ability to run lower psi or lower rolling resistance, but when mated with Stan's I never flat. Period. I aslo feel the ride is more supple, especially at the front. I think I have a better feel for what's happening under the tire, especially while braking. I don't know if its true, but that's my subjective opinion.

    5. As for rolling resistance one has to account for the tread design as well as pressures. The ramped center knobs on the Kenda BG/Nev 2.1s I'm running now roll way faster at the same pressures than the unramped Conti VertPro 2.3s they replaced. Aside from the tire sizes printed on the side walls I'd say both brands are more like 2.2s (comparing them to each other). Rolling resistance is also affected by how compliant or non-compliant the sidewalls are...and that's another factor in the equation of determining what pressures to run.

    I hope that helps.


  10. #10
    mtbr member
    Reputation: toothoogre's Avatar
    Join Date
    Sep 2004
    Posts
    79

    tight fit is critical

    Depending on the rim and tire combo you may have to build the rim cavity up enough
    so that you have a hardish time getting the tire on the rim. You'll notice how easily
    sloppy floppy tires will air up (and stay there) if you do this. A few of the Kendas simply refuse to hold air
    even with a lot of sealant due to their porosity.

    I've had great success building up rim cavities with some cloth tape and or door weather stripping for big boys who do pretty big high speed drops to flat or off camber slick rock on Mavic EX 729,
    321, sun MTX and Singletracks, DT 6.1, 5.1. You can use some glass tape to finish the job and build up the cavities on UST rims so that you can use non UST tires and get a nice tight fit.

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •