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  1. #1
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    Flying bikes with hydraulic...

    Anyone have a problem with hydraulic brake systems after flying / shipping their bikes? Can air pressure in the cargo hold affect the brakes? I had a strange thing happen recently.

  2. #2
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    cargo hulls are pressurized since the late sixties .....

    meaning if there is a pressure loss, than the silly masks are falling down in the cabin....

    Plus ..even if a total pressure loss occured at max height, than it would be equivilant to a 30 foot dive.....

    In other words .... nope .. you can tie that bike to the wings , pressure aint gonna do nuttin, ( super cold air will ...lol )


    thor
    brakemeister
    www.thorusa.com

  3. #3
    Formerly DMR For Life
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    Quote Originally Posted by Brakemeister
    cargo hulls are pressurized since the late sixties .....

    meaning if there is a pressure loss, than the silly masks are falling down in the cabin....

    Plus ..even if a total pressure loss occured at max height, than it would be equivilant to a 30 foot dive.....

    In other words .... nope .. you can tie that bike to the wings , pressure aint gonna do nuttin, ( super cold air will ...lol )


    thor
    30 foot dive....not a chance...most cabins (and cargo holds) are pressurized to 8000 ft with the aircraft flying @ around 30000...thats alot more than a 30 foot dive...an 8psi diff....pretty significant stuff for the human body...but not so much for a bike (as Brakemeister mentioned)

    If a disk brake system was sealed then yes it would be a problem....but as far a i know most if not all are vented systems

    DMR

  4. #4
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    Here's the scenario...

    Shipped bike from East to West. Assumed it flew. Hayes HFX-9's. Got the bike in Colorado and the rear lever would not return after squeezing. Squishy when pulled in (applied). Rear brake squealed like crazy when applied semi-hard. Had it checked out. The rear pads looked pretty bad, so a shop went to put new on. After installing new pads, rotor would not go back into caliper. Not enough clearance. Shop said the internal seals were swollen. Probably from wrong fluid being used. Prior to shipping I had the rear hydraulic cable replaced by a shop. Sounds like a no brainer, but I'd like some input from an experienced brake man.

  5. #5
    A wheelist
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    Quote Originally Posted by DMR For Life
    30 foot dive....not a chance...most cabins (and cargo holds) are pressurized to 8000 ft with the aircraft flying @ around 30000...thats alot more than a 30 foot dive...an 8psi diff....pretty significant stuff for the human body...but not so much for a bike (as Brakemeister mentioned)
    Hmmm didn't my diving classes teach me that pressure is doubled at 33'? So therefore 14psi (roughly normal atmospheric pressure) would become 28psi. So if the plane went high enough that there was no pressure (and it won't) then there would only be the removal of 14psi. We can't remove the equivalent pressure of a 33' dive. Did I miss something here?

    If a disk brake system was sealed then yes it would be a problem....but as far a i know most if not all are vented systems
    There is only one sealed brake system at the moment - Magura rim brakes - and I've flown with them and there was zero problems.
    Mike T's home wheelbuilding site - dedicated to providing Newby wheelbuilders with information and motivation.

  6. #6
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    If this is the bike you had at OTE in Fruita, the brake was bled with mineral oil which caused the rubber components in the brake to swell. I'd go back to your shop and discuss it. It had nothing to do with flying.

    Randy

  7. #7
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    dives right under water...right my bad
    DMR

  8. #8
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    Thanks, Bro...

    Quote Originally Posted by Randy@Hayes
    If this is the bike you had at OTE in Fruita, the brake was bled with mineral oil which caused the rubber components in the brake to swell. I'd go back to your shop and discuss it. It had nothing to do with flying.

    Randy
    When the bike returns, I'm taking it in. Any way they could call you to verify?

  9. #9
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    Have them call OTE and talk to Keith or Simon. I didn't acually see the bike but they described the problem and I confirmed their suspicions. All your shop needs to do is remove the reservoir cap and look at the bladder. It's about twice the normal size.

    Randy

  10. #10
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    Full Moon, shots o' Joe...

    I called my shop and described the problem. They are real receptive to making it right. Obviously he has to look at it himself. I appreciate the response.

    By the way, Joe's Ridge at midnight on a full moon with Simon, Jerry and Skip does not suck! Those guys were an absolute HOOT!! It took a full week to recover from the depression experienced when I left Fruita. Great riding, great people, great time! And a liquor store that opens at 8am. Y'all got it made.

  11. #11
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    Fluids do not compress, or expand with changing air pressure. Now if you had air in the brake lines, that could cause some problems.

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