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  1. #1
    switchback sculptor
    Reputation: erosive's Avatar
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    Fire started from hot rotors?

    Durring a recent descent down a local trail, i took a tumble and my rotor ended up resting against my calf, resulting in a nice defined burn.

    Has anyone ever caught some grass or loose debris on fire when laying their bike down after a run?

    odd question, i know...

  2. #2
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    hahahaha

  3. #3
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    Wood needs to reach ~572 degrees F before it will ignite. I don't think your rotors get THAT hot...

  4. #4
    switchback sculptor
    Reputation: erosive's Avatar
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    wood yes... but what about the dry grasses on the side of the trail?

  5. #5
    Dirt Deviant
    Reputation: savagemann's Avatar
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    I've actually thought about this before.
    I think dry grass could prolly be set a light by really hot rotors.
    Look, whatever happens, don't fight the mountain.

  6. #6
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    I've seen heat warped rainbow-colored rotors before, so I'd say it's definitely possible. However, it's not likely.

  7. #7
    switchback sculptor
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    maybe unlikely... but i would never forgive myself if i burnt down a nice trail.

    i think i'll just stop using them, faster is better right?

  8. #8
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    bike rotors cause fires. lets shut down more trails..

  9. #9
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    well i saw some guy lighting his cigarette on his rotor after a long downhill run... i was like "wow! rotors get hot!!" then i thought, "why is a bike rider smoking??"

  10. #10
    Underskilled
    Reputation: CaveGiant's Avatar
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    Quote Originally Posted by emtnate
    Wood needs to reach ~572 degrees F before it will ignite. I don't think your rotors get THAT hot...
    spot on
    autoignition temperatures need to be reached, thinks don't miraculously burst into flames just because we want them too.

    For that temp to be reached the rotor would need to be glowing brightly red.
    I have got a dull red before, so 500degsish, so it is possible, watch out when your rotors start glowing.

  11. #11
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    If you got your rotors hot enough....

    they could start a grass fire I suppose. However the mythical "average" rider isn't likely to get them that hot. Skin burns at a rediculously low temperature. 180 degree water can cause a nice burn if you're not careful. Skin is one of natures least heat resistant teguments. Most plants even when tinder dry require quite a bit more heat to burn than you skin does. Not saying it isn't possible to get rotors hot enough, but if you do you've either been on one hell of a downhill run or use your brakes way too much!

    Anyway, the likelyhood that you'll start a fire with hot brake rotors is very low. Deffinately not impossible, but not likely enough to worry about much.

    Good Dirt
    "I do whatever my Rice Cripsies tell me to!"

  12. #12
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    Quote Originally Posted by AlexJK
    well i saw some guy lighting his cigarette on his rotor after a long downhill run... i was like "wow! rotors get hot!!" then i thought, "why is a bike rider smoking??"
    maybe he wanted to spice up his smoke a little bit. what better way than to add some metal and resin to it?

  13. #13
    The Beast Breathes
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    Ah, ha, ha, that brings back memories. On a ride near 2001, I think, I was cleaning my rotors w/ alcohol and forgot to clean them off. Went for a ride on really steep, fast stuffand set the alcohol on fire.

    Good luck with that, mister 300-Mile Turn Radius.

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