Fast(er) bike

Discussion in 'Motorized Bicycle General Discussion' started by Bikeguy Joe, Mar 1, 2013.

  1. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

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    #1 Bikeguy Joe, Mar 1, 2013
    Last edited: Mar 1, 2013
  2. Groove

    Groove New Member

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    Somewhere on youtube (I couldn't find it just now), there is a hilarious video of this English guy (looks like a butler) riding a motorized bike. He's wearing a suit and hat. At one point he lays out in an aerodynamic position. If anyone can find that video post the link!!
     
  3. 16v4nrbrgr

    16v4nrbrgr New Member

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    When you add fairings you increase the frontal area but lower the coefficient of drag. On my OCC I experienced a couple mph increase in top speed and a much more comfortable ride at cruising speed because the screen creates a bubble of low pressure you ride in.

    Of course if your fairing is a flat piece of plastic placed perpendicular to direction of movement, yeah a fairing is all frontal area drag due to a turbulent large low pressure wake.
     
    #3 16v4nrbrgr, Mar 1, 2013
    Last edited: Mar 1, 2013
  4. wheelbender6

    wheelbender6 Active Member

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    I saw a post a few years back where a member made a mini fairing from an old motocrosser rear fender. He claimed to gain 4mph top speed.
     
  5. racie35

    racie35 Active Member

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    with the horsepower available ....isnt much to be gained probably.
     
  6. jji7skyline

    jji7skyline New Member

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    The wind buffeting around makes you feel like you're going faster anyway :p
     
  7. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

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    See, that's the thing...speed takes horsepower. Overcoming rolling resistance takes horsepower. We don't have much horsepower, so any advantage is going to help.

    Especially those who want to go fast(er).
     
  8. Toadmund

    Toadmund New Member

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    That's why I maintain my trim figure.
    For less air resistance while motorbicycling.

    What can a guy do with fibreglass and resin?
    Probably more work than it's worth for someone who lacks motivation.

    So failing making a wind cowling, one can at least keep low on the bike when you need less wind resistance.
     
  9. biknut

    biknut Active Member

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    This is kind of a relative statement.

    Actually there is, but you have to think about it a little differently than a motorcycle. A motorcycle goes fast enough to build up a lot of wind resistance all by itself.

    Motor bicycles you would tend to think don't, but the wind doesn't think. You can easily be trying to do 30 mph against a 30 mph headwind. That's a lot of wind resistance. In a circumstance like that aerodynamics can make a big difference.

    I've noticed on my bike that wind seems like a bigger hindrence than hills.
     
  10. biknut

    biknut Active Member

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    I've noticed that in the winter when the air is dense, there's a lot more wind resistance than in the summer when the air is thin.

    Personally I'm not motovated enough to care because my bike already goes faster than I think is safe.
     
  11. Toadmund

    Toadmund New Member

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    People ask me how fast does it go?
    Too fast for a bicycle, I say.
     
  12. Andyinchville1

    Andyinchville1 Manufacturer/Dealer

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    HI,

    Bike Nashbar used to sell aero wheel covers years ago.....They claimed you should be able to ride a bike 1 hear higher than without the covers.

    I bought 2 sets ( 4 pcs) and it seemed to help a lot!

    WARNING THO: Putting them on the front is NOT advised per the instructions because side winds can twist the steering (I used it for awhile for the aero drag reduction BUT it is true about side winds affecting steering....I took the ones off my front wheel just to be safe....I left the ones on the rear.

    Andrew
     
  13. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

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    I've seen those on racing bikes. A lot of the aero stuff goes on behind the vehicle. That's why short little cars don't get better mileage, they aren't shaped right (long enough) to allow the air to close behind properly. A couple years ago, motorcycle racers found that by directing the exhaust at the proper angle allowed gains of several mph.

    What I was getting at with this thread is that because we have so little hp, there is an advantage to be gained by any amount of streamlining.
     
  14. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

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  15. lambofgod121980

    lambofgod121980 New Member

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    I would love to know more about fairings - where to get them/how to make some. I deff notice lately (wind been about 15-20mph) that I can feel myself slowing down with every gust even when I lay myself out as much as possible. I'm a big dude at 6"1' 220lbs and in my opinion decent shape, and my body/clothing catches some serious wind.
    I would think if I could streamline my bike with some kind of decent fairings I could gain some speed. When I'm in my neighborhood its not such a big deal as the streets are fairly short and the houses and landscapeing create a decent wind break. However when I head out on the main roads with cars flying by me at 45 - 55mph the wind is deff an issue.
    I also have no delusions that I could make my bike a 0 wind drag w/o turning my bike into some kind of 8ft bubble looking thing. Bwahahahah I have seen solar bikes and such which are covered completely and I'm not looking to go that route. But would fairings like would be on a pocket bike help?
     
  16. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

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    For starters, I have seen windshields/fairings on recumbent bikes.

    Seems a good place to start could be to use thin lexan/plexi glass and aluminum tubing for a mount. You can shape lexan/plex with a simple mold carved out of foam and HOT water.
     
  17. 16v4nrbrgr

    16v4nrbrgr New Member

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    that won't work water doesn't get hot enough znd the foam would melt. Lexan melts at 380 F and needs a heat gun or an oven of sorts to be thermoformed. It works out well though if you take your time and the moisture level of the plastic has been reduced as much as possible.

    [​IMG]
    A nice side consequence of a fairing like this is that if your visor is fogging up, lean forward and the blast goes up your mouth vents and defrosts your visor really quickly.
     
    #17 16v4nrbrgr, Mar 5, 2013
    Last edited: Mar 5, 2013
  18. Bikeguy Joe

    Bikeguy Joe Godfather of Motorized Bicycles

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    Hmmm, sorry for the mis-info. I know we have done it with plexi-glas...I think, now Idon't know what it was.
     

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