wphamilton

From the testing I've done, I believe this is correct with windscreens (which I distinguish from fairings which have more full covering). However, recumbent riders report a discernible improvement with the wind-screens. I have to attribute that to the shape, size and positioning, typically different that what you'd see on diamond frames.

Like mine but it's not at all impractical. Dangerous possibly but practical.

Jax Rhapsody

This might sound stupid(which is why i never made a thread on it), but I've got an old army bag I use o carry laundry, coming from my house you have to go under a train overpass nomatter the direction. When I'm carrying laundry in this bag, it feels like I'm so much faster with it. I can climb out of those things with less effort and downshifting, and on level ground, I feel so much faster. This was on my Nishiki Prestige. with bill bars.

RChung

This isn't quite what I've found.

timtak

Zzipper fairing claim to reduce drag by as much as 20%, according to wind tunnel tests. Please see the chart on page 150 of the following pdf
https://zzipper.com/documents/HPV_Paper.pdf
If it is true then it is a hell of a lot more difference than purchasing a S-Works Venge, or (equally effective) shaving ones legs, getting tight fitting clothing, or an aero helmet.

A fairing would certainly have some effect as a rain shield, water droplets having more mass than air molecules. For that matter, the lower the rider's position, the warmer and drier they will be. This is very noticeable to those who have ridden aero bars in the rain.[/QUOTE]

For the time being, I will expect only this advantage. But if it is really slowing me down it will have go to and perhaps i will get a Zzipper. For the time being I am going to keep experimenting. I will make a notch in the bottom and put it upright and try to extend it upwards. It has cost me 10USD. I am having fun.

There is a specialized Windtunnel report on that.


I find that my vision is impeded by my eyebrows when I am in the drops

by timtak, on Flickr
So my frames would need to be above my eyebrows. It is clear that this is not the case with Cavendish's Oakleys for instance. I have tried cycling glasses and I could see the frames.

timtak

That sounds like it could be very possible. The area behind the ride is perhaps as important as what is in front.

Human Powered Vehicles of (Planet) Earth

Jax Rhapsody

I don't want say I'm more aero with a green cylinder on my back, I mean with my knowledge of aeridynamics, and savant mental imagry of such things, I figure the bag which is marginally wider than my torso, possibly smooths out the airflow around me versus my bare body or me and my backpack, probably causing a 6" or so wide strip of dead or ambient air directly behind the bag, the air may not even curve that far given the slow speeds. Probably acts in the same way an aero helmet works, or similar. The claim is still extreme, and effects would still probably marginal despite the feeling to say it was more aero.

Campag4life

Agree. Its a cool machine you have...not sure to call it a bike. It seems to be quite purpose built unlike a bicycle than can be ridden on all kinds of terrain including jumping off curbs etc. So from a practicality standpoint, it doesn't seem to wash. There are many different styles of bikes on the closed cycling road I ride...including recumbents scraping along the ground and 3 wheelers. The fastest guys in my town are on recumbents...they can hold 25 mph where most guys on a road bike can't. Staying with them is pretty futile. Only way I could on my road bike is with a supplemental motor which I don't have.
Recumbents have their place for sure and seem to still have an element of practicality versus an entirely enclosed bicycle and will be interesting what the future holds. I believe supplemental electrical power is the future to combat the tradeoff of ergonomics versus aerodynamics...but maybe well into the future where it will be more common place. But already there e-bikes around where I ride and the form factor and motor integration will no doubt change over time...smaller motor size can be offset with improved aerodynamics...a balance that can be improved moving into future. A top cruising speed of say 28-30 mph with a 50 mile range would be a good target.

RChung

That hasn't been my experience.

Carbonfiberboy 

I've been going by the results from John Cobb's '03 testing:
Tech Center

AFAIK, these tests were done with a pedaling rider, which will give different results from no rider and a dummy rider. You have newer, different results?

Carbonfiberboy 

Note that this reduction is achieved in a full crouch with the rider's eyes just above the top of the fairing. I think you would find that the fairing might increase drag in other positions, as was found in the BQ tests. For practical drag reduction, it's the average drag during a ride that's important.

Reynolds 

Why? If I wanted a motorcycle, I'd get a motorcycle.

RChung

Yes.

f4rrest

The obvious solution is a big beer belly.

Carbonfiberboy 

Descending muscles are very important.

wphamilton

I would have thought so, by my coast-down test showed that a full backpack was worse aerodynamically than on a rack but better than panniers.

timtak

There was a sidewind last night and I was blown into the centre of a road! Fortunately it was a country road, otherwise I would have been roadkill. It was making me slower in all but nose-to-fairing areo tuck, and the wind/rain protecting advantage will not match the danger, at least till January. The fairing is coming off.

It needs to be frame (head tube) mounted aswphamilton has been saying all along. I am not sure I will have time to develope head tube mount.

Zzipper is bigger and also handlebar mounted and would likewise cause me to be blown into roads, so I will not be buying one. Specialized is still in league with the UCI.

I guess I will just have to use my drops, and possibly save up for a recumbent.

I had also seen another non-Cobb set of results showing that a bottle on a bicylce downtube improved bicycle aerondymics and was persuaded. That is one of the reasons that I presumend that fairings could work on bikes since the bottle in this case is (acting as?) a fairing. But Specialized claims, in the following video, that bottles are better in the back pocket out of the wind since bottles on cyclocross downtubes reduce aerodynamics of bike and rider.


But then, Specialized would say that since they are in league with the UCI!;-)

Good point. My fairing is coming off.

That said, I feel confident that if the UCI rules permitted them there would be ways of improving upright bicycle aerodynamics using frame, rather than handlebar, mounted fairings, at least while in the drops, as demonstrated by the down tube mounted bottle data. And the weather protection advantages remain. I will try and think of ways of mounting one on my head tube.

K.Katso

Tim, judging by your Strava profile, you don't look like a half bad rider. Why don't you just train harder instead of worrying about all of this? Do you think you've reached you maximum potential already or do you just enjoy the tinkering? (nothing wrong with either, not trolling, just wondering)

timtak

Thank you.
I guess it is like getting a new bike, or some carbon wheels, or some tight new clothes - it is a reward or incentive to encourage me to get on the bike, in winter.
I have some clothes on order
Wholesale Product Snapshot Product name is 2014 New Winter Fleece thermal full zipper long sleeve cycling jersey/wear & bib Pants Set cycling clothing -BF0109
(and dream of modified time trial and recumbents)
And also perhaps I hate the fact that UCI rules appear to have stymied innovation. And also I know it is going to get cold soon. I came accross the fairing idea on a thread about poagies. Someone was using a spinach box in the place where I had my fairing.
And wphamilton's fairings on the same thread
https://www.bikeforums.net/commuting/...-pictures.html

Carbonfiberboy 

It's good to have fun with your bike, trying different things. That's how we learn. We don't have to accept everything as received wisdom. Sometimes it's good to challenge the way things are and see if they could be different. That's how civilization advances. And there are always going to be those who defend the status quo and see everything new as a challenge to their right to decree what is right and proper. And sometimes it'll turn out things are the way they are for very good reasons which we just haven't yet appreciated.

Reynolds 

Call me a retro grouch, but I wouldn't mind having as my main or only road bike a top quality one from 30 or even 40 years back. It weighs 9.5 kg instead of 7, so what? Total weight difference is 79.5 vs. 77, about 3.5%. That won't make me noticeably slower than I already am. Only thing I'd change is clinchers for tubulars, and that only because they are more practical.

timtak

Hear, hear.
Well, one of the reasons for this is that he UCI has specified the double diamond and that has affected the design. We'd probably be riding much lighter faster more cushioned bikes but for this.



I would also far prefer to clip into my pedals, shift using my brake levers rather than using levers on the down tube, click into the gears rather than have to find them, and ride on silky smooth carbon rather than steel.

bbattle

There are no UCI regulations preventing timtak from riding whatever bike he wants.

There's some Softride bicycles on eBay.

Carbonfiberboy 

Softride isn't all that great. Most folks bounce on them and lose power. The old Trek carbon Y-Flyer, though, it was a pity to lose that. Still, I've easily coasted right by a Y-Flyer on a DF. Again, it's the rider that makes a difference. Current DFs are plenty comfortable.

wphamilton

I hope this isn't too zombie for forum sensitivities, but I wanted to let you know that I finally got my Kawasaki windshield in from Aliexpress a few of weeks ago, and it works perfectly with my fairing! $20 well spent IMO. I am grateful that you brought this up with this thread.

RChung

It doesn't count without photos.