fairing missing from end bikeism

[Opik]

as bentors always go about the 1934 UCI ban, which came after Faure's record, how about talking about the other aspect of speed, which is the fairing. And fairing history is kinda murky and not clear.

I'm trying to search of the history of fairing ban, but have come into some conflicts. Many wrote the history like this:
https://bikefix.co.uk/information/recumbent-history

In the meantime various designers and bike enthusiasts had begun experimenting constructing cloth fairings. In 1913 the French man Etienne Bunau-Varilla began offering a fairing that could be fitted to a regular bike. German bike manufacturers like Goericke and Brennabor let riders of their teams take part in races with cloth-faired vehicles. In the following years various faired bikes competed with each other. The first race of this kind took place in Berlin in 1914. The Dutch world champion Piet Dickentman and the European champion Arthur Stellbrink from Berlin raced. The world champion crashed and died. Possibly as a result of the fatality, the UCI changed the rules in 1914 and specifically prohibited add-on aerodynamic devices such as fairings or nosecones. The faired racing events soon fell into oblivion.

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Problem is, if you look into Piet Dickentman wiki:

Died7 October 1950 (aged 71)
Amsterdam, the Netherlands

and other sites:
https://www.flickr.com/photos/letterlust/5099661062

Piet Dickentman did not dy in 1914 during that first demonstration race! Neither did the UCI forbid riding cloth faired bikes in 1914.

Quite a lot of sites about aerodynamic bikes are giving this noninformation.

Two things are confused here. The Rennbahnkatastrophe in Berlin in 1909, and the ban on recumbents etcetera by the UCI mid 1930.

As thre are some confusion, I think probably the 1934 UCI ruling also covers fairing

I think we need an addition of fairing into the bikeism as velomobiles are going to be more mainstream. Fairings are not only for speed, they also provide comfort for shielding wind, sun and rain, so they have practical uses. Also they can be places solar panels.

 

[woodguy]

I had been thinking about a fairing for my Q45, but when it was discussed at the Cruzbike retreat there was some concern about stability of the bike because the front end is so heavy. I haven't seen many Cruzbikes with a fairing, but living in Wisconsin I can imagine it would improve my comfort level on some of the cold days. Anyone have experience with a fairing on a Cruzbike?

 

[benphyr]

Hamish Barker had a fairing on his conversion kit. A Windwrap one from Teracycle that he had mounted for his long commute (42km if I remember correctly). I am the proud owner of that conversion kit minus the mountain bike frame. I also have the fairing which I mounted on my Catrike Trail and it worked great. Reminded me of a Sopwith Camel.

Anyway, you may be able to find more by searching the forums but I remember him saying that it his experience was:
- little to no negative effects on handling for his set up (fastened in front of the feet and to handlebar extensions about 6" above the bar - I think he had the bike set at 40 degree seat angle or slightly less.
- kept him completely dry from the upper chest down (full fenders of course too)
- improved headwind AND crosswind speed - I think he said 15% improvement in aerodynamic drag for flat, straight, no wind. Better when headwind involved.

I have never mounted it on my bike (only the trike) so I can't personally comment on that but I was just reading about someone else who had similar experience of much better into headwind and feels like a slight tailwind when in a cross wind. That might have been on the HP Velotecknik site reading about StreetMachine.

@woodguy you have ridden enough that you will be able to handle adding a little more weight to the front. For what they are worth there are my thoughts. If you do it please let us know how it turns out and remember pictures are awesomely appreciated.

 

[billyk]

I've ridden fairings on recumbents for decades, mostly for raingear. I'm a daily year-round commuter in Seattle ... nuff said.

There's quite a bit of discussion here over the years (seems like these topics get discussed, then forgotten, and we go round and round again). Simply searching "cruzbike fairing" will pull some up, including a detailed design I posted in 2014 (for a Q2):

https://forum.cruzbike.com/threads/new-homemade-fairing-for-quest.6959/

The big advantage of my design over the commercial ones is that my attachment is much lighter and less bulky. It's stood up to thousands of miles, including a few crashes, without any damage. IMO, Windwrap overdoes the structure.

This is a windy place, and I have never noticed any handling difficulty in thousands of miles. Crosswinds are just not a problem.

Here's a photo of my present fairing on a Q45:

https://forum.cruzbike.com/attachments/img_8812_reduced-jpg.7288/

As you see this is entirely homemade, which means it is only curved on only one axis. It's great raingear for the reasons @benphyr mentions above. Dry hands and feet are such a pleasure, it's somewhat out of the wind so warmer (uncomfortably so on a hot day), and the drivetrain stays way cleaner.

I used a blown Windwrap fairing for years on a BikeE, which gave significant speed increase above 15mph. But my homemade curved-in-one-axis fairing doesn't seem to give much advantage. I roll down one hill on my way to work every day at about 27-30mph, and the fairing really isn't much faster than without. Increasing the tire pressure makes a much bigger difference.

When I get some time (hah!) I intend to post instructions to build this. But this is a project for someone who enjoys working on their bike about as much as riding it ...

 

[Balor]

Fairings are tricky - partial fairings are marginally effective aerodynamically, up to and including working more like a parachute than a fairing ('rain roofs' for instance).
On MBB front fairing is particularly unviable because it exacerbates the problem of steering inertia and you get huge wind steer problem on top (like full disk front wheel, only worse I presume).

Rear fairings 'by themselves' are also marginally effective - they don't really capture highly turbulent air coming of your body/bike front bits, I have some ideas of increasing effectiveness that seem to work in CFD but they are not without their costs.

FULL fairing, that gradually 'parts' the air in front, accelerating it along the sides and than slow it down along the 'tail', creating a zone of high pressure that actually push your bike forward instead of 'sucking it back' (as a rear zone of separated flow does on a blunt body) - is an order of magnitude more effective than upright bike and many times more than the best unfaired recumbent.

Unfortunately, minimizing frontal area and Cd comes at, basically, maximizing lateral area and lateral Cd, leading to problems with wind guests and 'truck suck', which in turn require the vehicle to be low to minimize this effect - and, preferably, multitrack (with everything that entails).
You also get problem with extra weight, greatly increased size (basically requiring a garage), reduced visibility (due to low profile and streamlined shape being not 'eye catching') and vision, ingress/egress difficulties.

Basically, between unfaired bents and fully faired velomobiles there exists a 'no-mans land' where benefits do not (usually) outweigh the disadvantages.

Of course, if actually going faster is not your goal, but rain/sun protection there are multiple options, but that does not rally count as a fairing (no more than an umbrella).

 

[billyk]

On MBB front fairing is particularly unviable because it exacerbates the problem of steering inertia and you get huge wind steer problem on top (like full disk front wheel, only worse I presume).
...
Of course, if actually going faster is not your goal, but rain/sun protection there are multiple options, but that does not rally count as a fairing (no more than an umbrella).

My Q45 fairing is indeed not much "more than an umbrella", but then again that's my main need as a year-round commuter in rainy Seattle.

@Balor is mostly correct in the above except for the statement about "huge wind shear problems". My many years and thousands of miles riding on exposed roads in a windy place show that that is absolutely not the case. Please read my post above.

My experience with both professional (blown plastic, fully rounded) fairings vs my present homemade (curved in one dimension) fairing is that the rounded ones do indeed give an aerodynamic advantage, apparently by reducing the effective Cd. 10-15% speed increase in downhill roll-down tests at about 25mph. My present one does not.

On the other hand, my present fairing is designed so the rider's view is precisely along the straight line of the top of the fairing (until it bends down over my feet). The straight line is from "clears my hands" to "clears my feet". I essentially don't see it at all. This can't be achieved with a rounded fairing, which will necessarily be higher than the minimum rise and obstruct the close-in view. Since I ride in traffic and on the bumpy, potholey streets around here, that view is crucial and motivated me to make my simpler one.

But unless the fairing has substantial side area, it has little to no effect on stability or controllability, even in high winds.

 

[bladderhead]

You want a brolly. Is a fairing without sides any good for that? Rain in a crosswind goes sideways.

 

[billyk]

You want a brolly. Is a fairing without sides any good for that? Rain in a crosswind goes sideways.

I'll cop to it being mostly a brolly. Not a bit ashamed of enjoying dry hands and feet, and clean drivetrain. It sure makes it more palatable to get on the bike some morning when it's 37F and spitting rain. Like this morning for instance, when the fairing plus a simple raincoat kept me dry enough to arrive at work and not need to change clothes.

I really should post a complete description and build instructions, maybe this Christmas break could be the time.

Mine has folded-down "wings" extending about 4 inches sideways and down (maybe you can see this in the photo linked in my first post above). About a mile of my commute is across the main wind direction when it rains here, completely open and unprotected, but I'm moving at least 15mph forward, while the wind is about the same from the side. With those wings I just don't get that wet. I prove it by test many days each winter. Sure, if it pours I'll be wet, but that's not how it rains here, usually.

As above, this is not the fairing you want for speed. You need more rounded for that. But being able to enjoy a commute in the rain, not having to give much thought to the weather as I haul my bike out on a dreary morning, is a beautiful thing.

 

[Balor]

Well, to be fair, that's not a fairing. Fairing, by definition, is an aerodynamic aid to reduce drag. If it does not reduce drag - it is not a fairing, just like umbrella is not a fairing. It does not mean that it is not useful of course, but that's a different object with a different purpose... and there are similar devises for DF bikes as well, it may even work as an actual fairing:

I don't think that it is physically possible to make an actual, working fairing that does not add to lateral area however, otherwise we are looking at flat plate wind shield that will work more like a parachute.

LWB fairings come very close to being working (somewhat) fairing and be of litte detriment, but it mostly works because their aerodynamics is abysmal to begin with (by bent standards). (Like rain cover in video above).

 

[bladderhead]

But being able to enjoy a commute in the rain, not having to give much thought to the weather as I haul my bike out on a dreary morning, is a beautiful thing.

Bloody hell yes! I have always wanted a fairing. Do not give a hoot about the aero, just the brolly.

 

[billyk]

I don't think that it is physically possible to make an actual, working fairing that does not add to lateral area however, otherwise we are looking at flat plate wind shield that will work more like a parachute.

Ok. But we need a better word for my whatever than "umbrella".
I'm looking forward to the video you posted but right now I've gotta throw on my raincoat, pull out the bike, and go to work.

I'll just note that it might not take much lateral area to provide significant aero benefits. The Zzipper and Windwrap 3-d rounded "fairings" I've used have no more than a few inches of lateral area but give a 10-15% speed increase in roll-down tests. I wonder how much more you could get from even a full fairing.

 

[Balor]

I've used have no more than a few inches of lateral area but give a 10-15% speed increase in roll-down tests. I wonder how much more you could get from even a full fairing.

Zzipper fairing work on bikes that have very bad aerodynamics to begin with - like DFs and LWBs. Better lowracers with streamlined tubing and reclined position are very hard to improve with aerodynamic aids - this project is particulartly instructive:
http://www.recumbents.com/wisil/misc/nocom/tb/default.htm

For a while I've toyed with an idea of making a 'ducted' tailbox (thread on BROL). It does show some theoretical merit and confirmed by CFD (and I might find use of this idea after all), but otherwise effect not groundbreaking.

As for full fairing... Cd of a DF rider is close to 1. Cd of a perfectly streamlined shape is 0.04. - nearly two orders of magnitude less. As you may know, hour record on DF bike is a bit more than 50 kmh, while on a streamlined bike (also track at about seal level) is 92 kmh and likely set on a fraction of power it took to set DF record.

BM results are a bit misleading becaus they take place at high attitude and on a (slightly) downhill course.

I've been blitz-studying aerodynamics because I want to make my own velo:

Exactly because it is THAT good. Given conservative estimates, I should cruise at 40 kmh at 150 watts and on a more or less steep downhill I should hit 100 mph with ease.
Frankly, I am a bit bored by local trails and using public trainsport is a pain, so a velo (with Tetz-like 'light' e-assist) should considerably broaden my horizons, probably allowing me to travel up to 500 kms to brevets in other cities, leaving the battery and doing them under my own power.

Even given extra wheels sticking out, extimated CdA is 0.04 sans head, with head - 0.07 (yep, that's a large difference! I'll need to think of something).
Milan SL's CdA is actually better, but it is extremely low and not practical for our roads.

 

[benphyr]

Ok. But we need a better word for my whatever than "umbrella"....

It has a primary purpose that is rain relief but it still does decrease aerodynamic drag. I say call it a fairing and let scoffers scoff until they can provide you with a better one across all the categories: rain, aerodynamics, weight, cost, ease of construction, etc.

 

[billyk]

From Wikipedia "bicycle fairing":

A bicycle fairing is a full or partial covering for a bicycle to reduce aerodynamicdrag or to protect the rider from the elements.[1]

The rest of the article comments on the aerodynamics of various partial fairings, but in fact cites very few sources and it sounds like @Balor might be able to improve it.

But we are coming at this from entirely different angles. Orthogonal I would say. That velomobile would be of no use to my urban commuting, and my fairing of no use to you in trying to go 100mph. (I've ridden it at 40mph downhill, but wouldn't vouch for its stability at 100).

And mine is not a "flat plate"! See pic above. It curves in one dimension, and the folded "wings" add a kind of curve in the other.

 

[bladderhead]

extimated CdA is 0.04 sans head

It was a dark and stormy night. I was riding alone on a long lonely road. In my mirror I saw a strange shape that seemed to glow with an eerie white light. It was moving incredibly fast. It flew past silently, seeming not to touch the road and it nearly forced me into the ditch.

The ravings of a madman? A hallucination brought on by too much coffee at the Italian cafe? Or was it really the HEADLESS RECUMBENT CYCLYST?

 

[Balor]

It was a dark and stormy night. I was riding alone on a long lonely road. In my mirror I saw a strange shape that seemed to glow with an eerie white light. It was moving incredibly fast. It flew past silently, seeming not to touch the road and it nearly forced me into the ditch.

The ravings of a madman? A hallucination brought on by too much coffee at the Italian cafe? Or was it really the HEADLESS RECUMBENT CYCLYST?

I just want to avoid using a hood because it limits hearing and vision, but I will have to think of something (windscreen?) because aerodynamic penalty of head sticking out is pretty high.

 

[benphyr]

...HEADLESS RECUMBENT CYCLYST?

Thank you @bladderhead appreciation flowing your way.