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  • Warning for weight weenies…
  • epicyclo
    Full Member
    gifferkev
    Full Member

    Genuine, fake or web based promotion?

    mikewsmith
    Free Member

    money on viral advertising

    rusty90
    Free Member

    Quick back of the envelope calculation

    Density of air is 1.25 kg/m3
    To lift a 12.5 kg bike (27lbs) you need to displace 10m3 of air
    Assuming a gas of zero density you’d need a balloon 2.66 metres in diameter. (Can’t be bothered to work out what size you’d need for a helium balloon, but it would be larger)

    Balloon in video is clearly less than 2.66m (looks less than 1m) therefore it’s a fake.

    molgrips
    Free Member

    You only have to look at the way the bike isn’t dangling or swinging about to know it’s fake. Fun though 🙂

    mtbmatt
    Free Member

    What if the bike was nearer 20lb?

    growinglad
    Free Member

    Yeah, but that’s a Swiss balloon, not your common old tat bit of rubber 😉

    rusty90
    Free Member

    What if the bike was nearer 20lb?

    Stop it Matt, I’m supposed to be working.
    Oh, alright then
    You need roughly 1m3 of helium to lift 1kg
    So 20lbs (9kg) needs 9m3 of helium, giving a balloon 1.6m (about 5 foot) in diameter.
    Although that doesn’t really work because in order to inflate the balloon the helium would need to be under pressure so would weigh more so the balloon would need to be bigger than that.

    thepurist
    Full Member

    And they could’ve filled the tyres with helium…

    epicyclo
    Full Member

    Yes, but, it’s a 29er balloon… 🙂

Viewing 10 posts - 1 through 10 (of 10 total)

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