Ugly but effective, with fairing for rain and (i hope) aero!

Discussion in 'Conversion Kit' started by hamishbarker, Sep 19, 2013.

  1. hamishbarker

    hamishbarker Well-Known Member

    My conversion has gotten heavier - I added a fairing. But the fairing is GREAT for keeping more than half of me dry in wet weather, even really pouring rain my legs only get a little damp. No noise, the mountings I made are working great. Crosswinds are no problem. I can feel a little tugging in really gusty winds, but quite safe riding.

    Speed wise - I think about 5% more top speed but will have proper data soon (note the yellow hub - a low cost secondhand old powertap which I built into a velocity rim, so I will be doing some Chung method power data analysis soon to determine CdA and Crr with and without fairing (and possibly with both the old and new (shorter) rear shock. Initial indications seem to show a CdA around 0.32 and Crr 0.005 but poor data, so better estimates later. Note how low the old bottom bracket is now - means my seat is a little lower than the front bottom bracket, I made the mod to reduce frontal area a bit. New 100mm rear shock to achieve this (for kids bike I think? The original was 150mm, I chose 100mm to specifically make the lowering mod) cost a big $10 (new) including postage from Hong Kong on ebay. Seems to work fine.

    I have 1.75" tires on it. The Front is a Compass (same mould as panaracer T-serve, lighter casing for less rolling resistance apparently - soon testing will tell), the rear is still a panaracer T-serve I haven't bothered to change yet.

    The thing is heavy. 19kg. ugh. And ugly (especially with all the 3M retroreflective tape) But for my daily 23km commute (46km round trip), over 2500km so far, it's the business!



    The top of the fairing is supported on a couple of spinaci type bars (copies of cinelli spinaci aero handles for DF drop bars, not allowed in races these days so really cheap).

    Full fenders are also keeping me nice and dry.

    The little clamps out past the edge of the fairing hold my lights (not mounted in the photo).

  2. Charles.Plager

    Charles.Plager Recumbent Quant

    Starting to look quite

    Starting to look quite interesting.

    As long as you're setup to see how aero you are, put a sock on it (and a tail box).

    I think you could see some real improvements!

    Nicely done,
  3. hamishbarker

    hamishbarker Well-Known Member

    That is part of the plan. I'm

    That is part of the plan. I'm turning over ideas on the best way to configure it. I don't like the socks which are open all the way along the bottom.I'm thinking of enclosing everything aft from the down tube plus rear disc cover, then front sock over the front fairing, from the lower front edge straight back to join the rear sock. the only opening would be below pedals to about the front edge of the seat. Entry would be by a side zipper like a lightning f40.
  4. Charles.Plager

    Charles.Plager Recumbent Quant

    Hi Hamish,
    That sounds quite

    Hi Hamish,

    That sounds quite cool. I am very much looking forward to what you do (and may be stealing ideas)!

    Keep us posted and good luck!

  5. Eric Winn

    Eric Winn Zen MBB Master

    Hamish,When you are riding


    When you are riding are you looking through that fairing or over the top edge?

    Fun stuff, you and Jim Gerwing appear to be having a blast with this stuff.

  6. hamishbarker

    hamishbarker Well-Known Member

    I'm looking over the top.

    I'm looking over the top. It's hard to say whether it would be more aero to look through, as that would increase the frontal area a bit ( the fairing is of course much wider than my head, about same as shoulders. Anyway, looking through it would be no good with,raindrops on it.the rain coverage now keeps everything from lower sternum and below dry, so I just wear a rain jacket, not rain pants.
  7. I have also done some

    I have also done some experiments with a Streamer with cloth and coroplast.
    I did get some fast speeds with good weather conditions.
    I did notice side wind could be dangerous here the roads aren't straight and the terrain can vary.
    So when I come from a forest area to an open area with a curve the wind can really push the recumbent sideways. I never went down because of this but did get scared several times.

    I raced with these setups and it did get scary sometimes going fast down a hill passing other riders and leaning as much as possible to control the recumbent.
    When the wind was favorable it was like sailing and I don't think any other non-faired bike would be able to follow.
    It was a fun experience trying different setups.

    Most of these setups will make you slower climbing but you can increase your speed downhill and on the flat sections.
    I haven't used the Streamer for some time now.

    The recumbent I ride now most of the time is a Vendetta.
    On the other recumbents I couldn't keep up on the climbing sections.
    With the Vendetta I can easily keep up with the average club member on the climbs.
    I feel the Vendetta is fast enough without any fairing I'm able to pass fast pace lines and I don't have to worry about side wind.
  8. Charles.Plager

    Charles.Plager Recumbent Quant

  9. Charles.Plager

    Charles.Plager Recumbent Quant

  10. Charles.Plager

    Charles.Plager Recumbent Quant

  11. billyk

    billyk Well-Known Member

    Who made your fairing?

    Hi Hamish -

    With you on fairings for raingear. Yup, they help speed but mostly it changes the whole experience of daily commuting in a rainy climate (in my case, Seattle). What a pleasure to have dry feet! It's also a lot warmer - too warm for summer use, in fact. I suggest a long helmet visor which keeps rain from pelting into your eyes, and even can keep glasses dry.

    Where'd you find the fairing? How much did it cost? What model?

    I'm looking at replacing mine (15 years of near-daily use), which has scratches from a few crashes. Polycarbonate is incredibly tough but scraping on concrete at 15-20mph does some damage. Photos at:

    (Putting photo link here causes the site to think this is spam. These photos have been posted here before. You can find them if you want.)

  12. hamishbarker

    hamishbarker Well-Known Member

    4000 commuting on a cruzbike conversion

    Just ticked over the 4000th km on my cruzbike conversion today. Almost entirely it has seen daily 46km commuter duty, except for two sessions of Chung method aero testing on weekends.

    Good things:
    -the windwrap gx fairing and fenders makes rainy day riding almost no inconvenience. Dry shoes, dry drive train, nearly dry legs, i just need to wear a rain jacket.
    -never any wrist or neck discomfort. Occasional minor aches in the backside until i got the lower seat part angle dialed in. I replaced the two big hose clamps for the seat pan bracket with three 6mm bolts by drilling and tapping the holes into the frame top tube.
    - low cost (as long as one does not get excited about putting on better wheels!)
    -efficient. The fairing cuts drag (CdA) by about 12 percent according to one test session with and one without, but more data would be good to have when i find time and energy (Chung method actually makes it pretty easy to get good data sets).

    Bad things
    -heavy, because the donor bike was already 16kgwithout fenders, fairing and (backpack) seat bag the conversion is now19kg.
    - too different, drawing too many comments from Co workers who regard it as a "mad inventor creation with no advantage over a regular bike"
    - trickier to work on the drive train or brakes because the front end wants to swing around to the rear when the bike is standing.

    The good outweighs the bad for me, but if my commute was hilly i would be more motivated to do something about the weight, suchas search for a frame with compatible geometry at lower weight than the original, junker-quality donor frame.

    I have bought a vendetta (!) but don't have possession yet ( its in Australia waiting for me, as i expect to travel there soon and will save on shipping it), but the conversion frankenbike will remain at least my nasty weather bike when the V arrives. the cost savings of riding a conversation have thus been destroyed (or well used, depending on one's point of view. :) )
  13. Charles.Plager

    Charles.Plager Recumbent Quant

     Thanks for the update. 12%

    Thanks for the update. 12% is nothing to sneeze at. I'd love to see what happens if you socked it with a tail box...
  14. billyk

    billyk Well-Known Member

    one data point re fairing speed increase

    There's a hill I roll down every day on my way to work, so I've tested the speed gain without fairing (summer) and with (winter). This is on my Quest 2. Unaccounted-for variables include tire pressure (mainly).

    I approach the crest as close to 15mph as I can. There's a crosswalk at the top where I check this. Then I roll down freely. Without fairing the average speed at the bottom is 23.5-24.0mph. With fairing it is 26.5-27.5. That's about a 13% increase.

    Photos of the fairing and its mounts are at

  15. baov

    baov Active Member

    Is the plastic windshield

    Is the plastic windshield heavy? Why not just stretch fabric over a frame, then you could remove it when you don't need it. Kinda like the Hase Klimax.

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