Getting Aero - Speed Gains

Discussion in 'Performance Mods' started by lowracer, Mar 11, 2012.

  1. lowracer

    lowracer Member

    I've been an avid cyclist for many years & have owned & raced many different type of bikes ranging from Road, Track, MTB, BMX, Lowracer, Tadpole trike, Recumbent...etc
    On all of the bikes I've pedaled, lowering my body into an aerodynamic tuck (time trial position) has increased my speeds by reducing aero drag.
    One bike I owned was known as a Lightning F40 (see 1st pic) & was basically a 3/4 faired recumbent (just head sticks out) with a fiberglass nosecone & fabric body (which I later replaced with a coroplast plastic body for better aerodynamics & speed). I estimated the Lightning F40 gained ~40% speed advantage being mostly faired (max ~30 mph unfaired, ~42 mph faired). Human powered bicycle speed records in excess of 80 mph have been set due to extreme aerodynamic bodies.
    The full fairing 2 wheel bikes are awesome until the wind blows, then the sail effect created scary situations & unpractical for street usage.
    Recently I began surfing for aero body fairings for upright bicycles & landed on Gravity Bikes. These BMX bikes built in the 80's & 90's with very slick motorcycle type fairings to race down hills. They are making a comeback & the fairings look slick for MB applications.
    I would like to build a fairing onto one of my three MB's to see what kind of aero gains are accomplished, & not just for speed but for efficiency & comfort. Smaller engine MB's could see significant gains in performance & efficiency by lowering the power required to move at any given speed.
    I also added a bubble & coroplast to a tadpole trike creating a 3/4 fairing (similar, but a crude variation of the slick velomobiles available today such as the Rotovelo by Trisled (see pic). The trike handled the wind much better than the F-40 but had a lower top speed, was heavier & took up more road width.
    Anybody have any ideas/comments about partial fairings and how they can be integrated onto Motored Bikes for performance, efficiency, comfort?
    -Lowracer-
     

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    Last edited: Mar 11, 2012
    roughrider likes this.

  2. motorpsycho

    motorpsycho Active Member

    I don't know how much the fairing would help with speed, but someone could make a really cool looking, cafe type racer with that blue style fairing that's on the bike in the 4th picture.
     
  3. Al.Fisherman

    Al.Fisherman Active Member

    Air flow for cooling the engine? I like that one also. that picture and 2nd row center,I know same same. What NO peddles?
     
    Last edited: Mar 12, 2012
  4. motorpsycho

    motorpsycho Active Member

    I think there's no peddals because they are gravity bikes, meant to coast downhill at high speed.
     
  5. lowracer

    lowracer Member

    Yeah, these gravity bikes wer emeant for racing downhill on the streets without pedals.
    I think since we MB'ers need pedals, a fairing such as the blue one in the pics could improve both performance & fuel efficiency without much of the drawbacks of a larger fairing (wind blown)...
    -Lowracer-
     
  6. HeadSmess

    HeadSmess Well-Known Member

    hardest bit with an upright style bike is making a fairing that looks decent... most everything ends up looking like a cop bike, or simply lame...

    the performance gains are worthwhile though :)


    mmmm, gpv with small brushcutter :)
     
  7. lowracer

    lowracer Member

    I was experimenting with mouting a lightweight aluminum rack on the front & attaching a small milk crate that would also serve as mouting points for some aero shaped plastic material....see pic
    -lowracer-
     

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  8. lowracer

    lowracer Member

    Today, I got the milk crate nicely mounted using some aluminum bar & angle aluminum. Also incorporated some cheap handlebar mounts made for mounting water bottle cages to handlebars. I can now carry one of my two plastic gas cans (as large as 2 gallons) for long travels without gas stations fill-ups with extra room for stuff. Now I want to get some plastic fairing material to mount over & in front of the basket to get aero...
    Still researcing blown lexan type fairings from ZZipper & Mueller, but also might just experiment with some thin plastic sheet (like those roll up snow sleds) or coroplast to create a decent shape to break the wind...
    -lowracer-
     

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    Last edited: Mar 17, 2012
  9. mbatl

    mbatl Member

    Any updates on your front fairing idea?

    That blue fairing bmx style bike looks nice. That would be great for a long mb trip and it just look so awesome. People would crash their cars trying to see an standard upright motorized bike with fairings!
     
  10. lowracer

    lowracer Member

    mbatl,
    I havent gone any further with the fairing plan. I removed the front milk crate from that bike & re-mounted the engine onto the front wheel.
    Speaking of cars, I had two cars stop me a few days ago. One beeping its horn & holding up traffic, the other cutting across a field & hopping down off a sidewalk curb just to stop & ask me where they can buy one & if mine was for sale.
    I directed them to the Dax & Staton websites.
    Maybe there is a real market for these MB's?
    -Lowracer-
     
  11. happycheapskate

    happycheapskate Active Member

    There is a market for them. We are it. hahaha. If I see someone driving to get to me, I haul away! You are pretty brave. I would assume they were intoxicated cagers coming to start a fight. I've heard of cagers even driving onto bicycle paths in order to car-murder bicyclists.

    I keep little flyers about the Dax Friction Drive for polite curiousity seekers, but no one in several years has actually called me or bought one. They expect me to build it for them for free. hahaha. No way. I think it is just a fun diversion, to them, a novelty. One auto parts store worker kept asking me about it for weeks, but then said it was "too slow" for him. :rolleyes7: When I was single and working for peanuts, I would have loved to have 1 or 2 of these bikes to avoid car expenses!
     
  12. roughrider

    roughrider Member

    Thanks, lowracer for posting those useful photos. I'm currently working on a model boat and some bicycle fenders, all made out of laminated wood. I have been considering how to apply the same techniques and materials to fairings. It was nice to see how others had built them.
     
  13. lowracer

    lowracer Member

    Its an old thread, but I needed to revive it after my wife found these old pics today of some of my cycling contraptions from yesteryear.
    Getting more aero never goes out of style!
    I only wish I had been into adding small gas engines to bicycles back in the days these pics were taken.
    I would have added an extended swingarm & engine mount similar to '2High' the motorized tall bike to the Greenspeed GTR trike you see in the 1st few pics. Low outside the fairing mount would get the noise and exhaust away from my head and allow engine cooling. The entended rear swingarm also for added stability.
    The Lightning F40 (yellow bike) was too scary in crosswinds & when trucks would pass at speed to even consider adding an engine, but that bike was awesome & fast!
    2nd trike in the body is a Windcheetah.
    Also had a Gold Rush Replica and a Optima Baron but never fully faired those.
    Cheers,
    -Lowracer-
     

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    Last edited: Apr 21, 2014
  14. max350

    max350 Member

    Combining handlebar/rack, It is a smart solution for a front rack
     

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  15. RichieRich888

    RichieRich888 New Member

    I have a poket bike faring I'm going to use on one of my bike's just don't know Wich one to use it on
     
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