High Speed Rear Blowouts

Discussion in 'Motorized Bicycle General Discussion' started by Charged-Reacter, Oct 25, 2009.

  1. Charged-Reacter

    Charged-Reacter New Member

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    I am using a GEBE Tanaka 40cc belt drive with a expansion chamber exhaust
    and a high performance carburetor and I am having trouble with rear blow outs.
    I was going 35mph for about 9 miles with throotle left to spare. The tires , tire liners,
    and slime tubes and wheel set are of decent quality. The trouble is at the valve stem,
    either the tire and tube is slipping causing this. Does anyone else have this problem
    while going at higer speeds? How can a person fix this issue? I am using about 60psi
    in both tires. The front tire seems to be doing ok at these speeds. Will I have to go to
    clincher style rims?
     
  2. bandito

    bandito New Member

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    Whats the max tire pressure for your type of tires? It seems the tire is slipping with the tube and tearing your valve up. Whats your rim size and the size of your tube and tire? These answers will help folks to address your problem. How wide is your rim? If the tire slips it will take the tube with it.
     
  3. HoughMade

    HoughMade New Member

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    How close to the maximum recommended pressure are you running (60 psi, i know, but what do the tires say). I think it would be advisable to run closer to the max than the min.
     
  4. Charged-Reacter

    Charged-Reacter New Member

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    The tire size is 26x2.0 with maxium 65 psi.
    The tube size is 26x1.75-2.125.
    The wheel measures outside at 1 inch.
     
  5. akeyma

    akeyma New Member

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    How about drilling out the stem hole in the rim to acomadate a rubber grommet and then install the stem through the grommet?
     
  6. upsrogue

    upsrogue New Member

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    My fix and so I don't even worry or think about a blow out is at Walmart they have a solid rubber tube for less than $20.00 each, they are hard to put on (and to take off) but that means to me they will stay on under extreme conditions. I don't go over 20 mph because I like to cruise and enjoy the ride and also be able to look around and see who is about to hit me in a car and the solid tube takes away one more worry.
     
  7. Charged-Reacter

    Charged-Reacter New Member

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    I am real happy about how this mb performs riding wise. I can
    narrow in on a small strip of payment without reducing speed and
    not drift out. The bicycle is a Firmstrong CA 520- 7 SPEED. The
    valve stem did seem tight when installing with the rim tape. I will try
    akeyma suggestion. Thak you for the replies.
     
  8. Retmachinist

    Retmachinist New Member

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    Find out what the speed rateing is on your tires. Most all these cheap bike tires are NOT high speed tires. I have been buying only high dollar tires, such as Maxxis, Michelin, & Continentals since talking to a friend of mine that has been into bicycling all his life.
    I think the most important part on the bike for safety is the tires.

    John
     
  9. lilhog

    lilhog New Member

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    duct tape......
     
  10. bandito

    bandito New Member

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    You have the right size tire and tube on the rim. You might try increasing the pressure by say 10lbs. Does the valve stem fit real tight in the rim hole when you install the tube? Mine just drops in on my rim and fits very loosely in the hole. Is the rim hole jagged and may need to be filed smooth?........."Q: What is the deal with rim locks?
    A: Rim locks are used on wheels to prevent your tire from slipping around the rim. This can occur if you are running your tires at very low pressures. Common when riding off road. If your tire turns on the rim it can pull the valve stem through the wheel or tear it off completely leaving you with a flat. They are fairly simple to install but it requires removal of the tires and tubes and this can be more work than the rim lock installation. The rear is the more critical wheel to lock as it is subjected to the forces of driving the bike forward. Install them opposite the valve stem to minimize the affect they will have on wheel balance.
    Riding Tips FAQ for Tips on Riding in Sand or Off-Road."
     
  11. bandito

    bandito New Member

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    Every thing I can read on tire slippage on the rim is related to low tire pressure or the bead not being seated properly on the rim...... Scwalbe tires says to over inflate a tire a little to correctly seat it if it isnt. If the bead isnt seated properly you can tell by an edge slightly above the bead not being uniform all the way around the edge of the rim. You should be able to see this edge when the tire is fully inflated......my eyes are getting buggy I hope this helps. Is your tire pressure reader accurate?
     
  12. Earthman

    Earthman New Member

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    Slow down! Bicycles and bicycle hardware are not designed to go faster than you can pedal. You are pushing the envelope, risking life and limb without knowing it.
     
  13. MaxPower

    MaxPower New Member

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    I had a high speed tire blow-out. green slime everywhere :) my solution, don't go so fast. I know you can get a ticket in Tucson for going over 20mph.
     

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  14. bairdco

    bairdco a guy who makes cool bikes

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    slowing down isn't a solution, it's a compromise.

    it's a pretty common problem. seems like it mostly happens with thicker tubes.

    i dunno if this would work with slime tubes, 'cause i'd never go near them (i've seen some cool ghostbuster effects when they blow) but to properly seat a tire and tube when you first put them on, is to inflate them, then let all the air out, then fill them back up. this helps to make sure you don't have a fold or a twist in them.

    one trick i've done is rough up the rim where the bead of the tire sits. you don't want it jagged, you want like a knurled surface. gives the tire something to grip.
     
  15. BarelyAWake

    BarelyAWake New Member

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    Truer words are rarely spoken! :D

    Besides, most of the folks on this fine forum ride in the 30mph+ range - the rest do too, they just fudge the numbers lol

    Yeah, I know there's a few that Sunday cruise - but I'd bet they get riled from time to time though, gotta clean the cobwebs out right? ;)
     
  16. Earthman

    Earthman New Member

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    No, it's natural selection (see The Darwin Awards).
     
  17. bairdco

    bairdco a guy who makes cool bikes

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    if you wanna talk natural selection, the slow get eaten...
     
  18. bandito

    bandito New Member

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    Tell a turtle that and he just might smile at ya! Ants might give ya a hollar too.
     
  19. bairdco

    bairdco a guy who makes cool bikes

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    what i meant, originally, is telling "Charged Reactor" that the way to solve the problem of high speed blowouts is to "slow down," isn't an answer. that's like saying, "if you don't ride the bike in the first place, you'll never have a flat."

    as far as natural selection and darwinism goes, if we used the same rationality as "don't do it" we, as a species, would've never survived, and the ants and the turtles would'nt even remember a time when those scared, biped creatures hid in their caves...

    so there. nyaah nyaah
     
  20. xlite

    xlite New Member

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    Turtle soup, chocolate covered ants... nuff said. :)
     

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