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  1. #1
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    29er TN719 rim, Geax Saguaro, ghetto tubeless -my experience

    Just converted my 29er TN719 rim to ghetto tubeless (http://www.go-ride.com/Articles/ghetto_tubeless.html), using a Tioga 2.35 26" tube.

    The tube was quite heavy - about 225g, but I weighed the cut off parts and they were about 150g, so the ghetto rim strip was left weighing about 75g.

    The tyre I used, a Gear Saguaro, was this one from Jensens:
    http://www.jensonusa.com/store/produ...x+Saguaro.aspx

    The Saguaro I have is the "Tuned Spring Casing - Phase 3.1" version (whatever that means), rather than the TNT (TubeNoTube) version.

    The Geax website (http://www.geax.com/vedit/pagina.asp~pagina~2317) is a bit hard to understand, but it seems there are three versions of the 29er Saguaro 2.2" tire:
    1. The "Foldable" version, which is the lightest at 640g, and I think the same as my Tuned Spring Casing tire (the weight seems about the same)
    2. The "TNT" version, at 840g, which requires a special inflation with "Pit Stop" containing "foam latex", in order to be tubeless
    3. A Tubeless version, weighing 940g.

    After installing the tube rim strip, I pumped up the tire without any sealant (using a bit of soapy water) - no problems inflating with a hand pump.

    Surprisingly, the Saguaro seemed to hold the air fine without sealant, with no loss in pressure after an hour. Still, I deflated and chucked in one scoop of Stans and one of Slime, then reflated and did a bit of a shake. Absolutely no sealant bubbled - unlike a Hutchinson's Barracuda, which leaked like a sive for a couple of hours.

    Lets see how this goes from here...

    One thing the worries me slightly, is that air pressure will push the tube rim strip into the nipple holes and might eventually puncture it - anyone have any experience with this?

    Cheers
    Nic

  2. #2
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    If youve used these rims with tubes before and didnt have an issue it should still be the same.

  3. #3
    himom!
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    You took the rim tape off?

  4. #4
    Former Bike Wrench
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    You need to use a rim strip with ghetto tubeless

  5. #5
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    Rim tape, what rim tape?

    I did not remove any rimstrip - just used the rim as it came. I have previously used Mavic 819s which don't have nipple holes (and no rim tape). The youtube "how to" video does not say anything about a rim tape, but the rim used does appear to have yellow tape over the holes.

    I thought the slit inner tube there to keep the air from escaping through the nipple holes and around the valve stem.

    There seems to be some confusion as to the purpose of different components to go tubeless, Obviously you need to deal with all potential air leakage, ie:
    a) through the nipple holes
    b) around the valve stem
    c) along the bead
    d) through the tire

    With my tubeless ready 819 rms, a) is not a problem as there are no nipple holes (only one layer of the rim is drilled) and b) is dealt with by the Mavic valve stem which has an o-ring. A UST tyre deals with items c) and d) - obviously you can still add a sealant for punctures. With a non-UST ture on this rim, the sealant fills microscopic holes in the tyre and hopefully between the bead and the rim (some tyres seem to be serrated here, make a seal difficult to obtain).

    With the TN719 rim (which has nipple holes drilled right through), the slit inner tube deals items a) and b) and also changes the bead contact from being metal-rubber to rubber-rubber, which you would think would improve the seal. The only logic I can see for using tape under the tube to seal the holes first is not to avoid air leakage, but to support and protect the tube - question: is this really an issue at MTB tire pressures?

    If you remove the tire for any reason, it seems it would be almost impossible to reseat the slit tube between the tire and the rim bead. Researching this, it seems that some people have just pushed the slit tube in, which means that you need a seal between the tube and the rim plus the usual tire to rim seal - so obviously more potential for air leakage, but it probably works. I guess you could glue the slit tube into the rim first using PVA or latex or sealant or whatever. Any comments?

    Cheers
    Nic

  6. #6
    Former Bike Wrench
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    is this really an issue at MTB tire pressures?
    Go for a few rides with tubes and no rim strips on those TN719's and you answer your own question.

    Stan's and Ghetto still need the spoke holes covered with a rim strip or tape...it will have no effect on the Ghetto setup other than protecting the tube/liner from bing cut by the spoke holes. I used strapping tape myself which is thin, light, but very strong.

  7. #7
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    Took the wheel for an outing on Wednesday night...

    ... and it worked fine.

    Actually I did 25km in the bush, at night, with no tools, spare tube or anything (accidently left my backpack at home) - so took a slight chance on having to walk out pushing the bike, but fortunately no problems at all.

    Anyway, I'll now remove the tyre and have a look if there is any damage or marks on the slit tube rim strip.

    Cheers

    Nic

  8. #8
    Stray Bullet
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    Just use Stan's: rim tape, valve stem, and goo. Works like a charm for me. No weight penalty for having half a tube in there.

  9. #9
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    Rode again today - gee I like this tire, but...

    I did buy some 3m strapping tape, and will take the kind advice given above and cover up the holes.

    Thansk
    Nic

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