tube came out with fold marks

Discussion in 'Dakar champion (950/990)' started by keener, Dec 8, 2012.

  1. keener

    keener Speed changes you.

    Joined:
    Feb 24, 2010
    Oddometer:
    2,266
    Location:
    Toronto, Canada
    I meant to post this for a while...I change a Hydano rear tire of my 950 that lasted over 17000km (Toronto, California round trip + riding more locally).

    Anyway, the tube came out like this? What does it mean? Was the tube too big?

    I think the size was 140, not sure. It was a ultra heavy duty. I had no problem and did not feel anything unusual while I had that tube and tire on.

    [​IMG][​IMG][​IMG][​IMG]
    #1
  2. Denalidirt

    Denalidirt High Plains Drifter Supporter

    Joined:
    Jul 25, 2006
    Oddometer:
    1,140
    Location:
    Denali, Ak.
    looks like it may have been twisted within the rim.
    #2
  3. Dustodust

    Dustodust Long timer

    Joined:
    Oct 9, 2009
    Oddometer:
    1,568
    Location:
    Cedaredge CO
    Hmmm
    I would guess that the tube was stretched out like a balloon inside the tire, and with no air pressure it relaxed into that appearance of kinked position

    I like to use Talcum powder to allow the tube to slide in the tire casing

    I am careful not to use powders containg corn starch in place of talc because corn starch liquefies when heated and gets weird and gummy, its OK on a babies butt but not optimum in a tube tire
    #3
  4. Dustodust

    Dustodust Long timer

    Joined:
    Oct 9, 2009
    Oddometer:
    1,568
    Location:
    Cedaredge CO
    Did you have talc in there ?
    #4
  5. Denalidirt

    Denalidirt High Plains Drifter Supporter

    Joined:
    Jul 25, 2006
    Oddometer:
    1,140
    Location:
    Denali, Ak.
    I think that the tube was filed to pressure with the folds in the tube. I think the tube wasn't placed in the tire as flat as possible, when air was put in the kink could not expand horizontally and this kink was created as the tube pushed it vertically against the rim and tire. if you look at the two folds you can see that there are other unnatural lines on the tube as well. They line up with the kink and kind of spiral around the tube like the threads of a screw Talcum would help for sure, reducing the friction between tube and tire.
    #5
  6. Denalidirt

    Denalidirt High Plains Drifter Supporter

    Joined:
    Jul 25, 2006
    Oddometer:
    1,140
    Location:
    Denali, Ak.
    It looks like the tire slipped on the rim about two inches. Without a rim lock this could also cause the tube to look like that, but I know how hard it is to break the bead on the 9xx rear so I think tire slip may be less likely. Again just my 2 cents.
    #6
  7. FakeName

    FakeName Wile E Coyote SuperGenius Supporter

    Joined:
    Jan 1, 2007
    Oddometer:
    2,157
    Location:
    San Diego
    Maybe it is a 21" tube?
    #7
  8. Weldit

    Weldit Been here awhile

    Joined:
    Nov 4, 2009
    Oddometer:
    341
    Location:
    Ontario Canada
    I like to let the air out after seating the beads
    this way the tube can relax - hopefully letting wrinkles unfold
    maybe even bounce it on floor to help
    then put air back in to final pressure

    also I always put the tube in the tire with a small amount of air in it
    this way avoiding some wrinkles and helps stop the tire irons from pinching tube
    somewhere a guy showed the right amount of air was such that the tube would
    just kink over one of your fingers.

    I also use baby powder - will have to check if it has any corn starch ?
    #8
  9. Deepc

    Deepc Been here awhile

    Joined:
    Apr 11, 2011
    Oddometer:
    299
    Location:
    St. Petersburg, Florida
    I had the same problem. It was also a heavy duty rear.
    #9
  10. geometrician

    geometrician let's keep going...

    Joined:
    May 25, 2008
    Oddometer:
    1,411
    Location:
    West-By-God Virginia
    That pic wasn't as bad as I thought it was gonna be- I've seen tubes come out of tires that have literally been twisted sidways and filled, with fold lines wrapping around the entire tube. These were on customer bikes where the tire had been (unknowingly) used for years, so even though scary they still (somehow) worked!

    +5, especially on leaving a small amount of air in the tube- it helps on manual tire jobs & tire changing machines (DAMHIK) I hate pinched tubes caused by my own hands!

    my dad taught me to remove the valve core to quickly deflate the tire to help line the tube up. If it's a tough tire/tube job, I'll even fill/de-air twice.

    Some baby powder is corn starch (turns out talc is carcinogenic as well as a repiratory irritant) but most isn't.
    #10
  11. Dustodust

    Dustodust Long timer

    Joined:
    Oct 9, 2009
    Oddometer:
    1,568
    Location:
    Cedaredge CO
    You might be Ok with corn starch , unless the tire gets hot . When corn starch gets hot it absorbs moisture from the atmopsphere better , heat increases the corn starches ability to absorb moisture and air is 30% moisture, Knobbies generate a lot of heat on the road., Wet and warm the cornstarch can crosslink and turns to glue.
    Does the opposite of what was intended . The glue on envelopes is cornstarch. . I have taken out tubes and wondered what that sticky gunk stuff was and pinned it down to corn starch

    I thought the carcinogenic suspect of Talc was still debatable , I'm sure we ride through much worse dust than that.on an average desert ride
    you can iuse cornstarch powder
    I prefer the talc
    #11
  12. FakeName

    FakeName Wile E Coyote SuperGenius Supporter

    Joined:
    Jan 1, 2007
    Oddometer:
    2,157
    Location:
    San Diego
    [​IMG]

    Keeps my tubes cool, dry and comfortable. Nicely scented, too.

    Besides, it's in my gear bag.
    #12