Drag reduction for upright bicycles

[freebeard]

Rick Tegelaar interview: Meshmatics Chandelier for Moooi | Design Dreams | Dezeen

At 1:11 you can see his techniques for forming compound curves with [rather high-end] chickenwire.

[matt36415]

Or just get a timetrial bike and skinsuit. They are pretty unstable, not good for turning...because of the geometry but they produce good aero

[JulianEdgar]

Originally Posted by matt36415

Or just get a timetrial bike and skinsuit. They are pretty unstable, not good for turning...because of the geometry but they produce good aero

The requirement was for a commuter bike, and - if we're up for outright low drag - a recumbent velo would kill a time trial bike.

(Basically all fast, low-drag pedal machines are banned from competition. It gets me very cross, because people then assume that fundamental bicycle tech stopped in about 1920.)

This is state of the art in low drag cycling, not a time trial bike...



It still brings me out in goose pimples watching this:

https://www.youtube.com/watch?v=qYeuTXj1FY8

[freebeard]

Are the cameras in that stalk? Awesome.

duckduckgo.com/?q=ant+farm+media+burn

What goes 'round comes 'round.

[Grant-53]

The nose section has to be strong in compression both because of pressure and for crush space in a collision. One can make a set of aero bars from a pair of bar end grips, some aluminum angle stock, and tubing that fits on a flat handlebar. The speed limit for most roads commuters use is 25-30 mph. Back angle will depend on riding style and traffic conditions. A low drag shell is needed to get energy consumption down to 0.1-0.2 hp. The ground clearance of the shell would be much higher so that a rider can put a foot down at a stop. The simplest set up is a parabolic nose and a conic tail piece ala Oscar Egg's Rocket.

[Grant-53]

Doval, Peter Nicholas, "Aerodynamic Analysis and Drag Coefficient Evaluation of Time-Trial Bicycle Riders" (2012). Theses and Dissertations. Paper 28.
Cd listed at around o.6 at 0 yaw.

[JulianEdgar]

Originally Posted by Grant-53

Doval, Peter Nicholas, "Aerodynamic Analysis and Drag Coefficient Evaluation of Time-Trial Bicycle Riders" (2012). Theses and Dissertations. Paper 28.
Cd listed at around o.6 at 0 yaw.

But don't feel bad matt36415 - as I said, because proper aero bikes are banned* from pretty all competition, most people have no idea of what is really possible.

(*By that I mean: no small wheels, no recumbents, no fairings. Some of these have been banned in competition for over 50 years!)

[skyking]

I know it is late, but I would add that it would nice to think of things that:
1: is compact enough for inside commuter trains.
2: can survive a trip on the front of a bus.

I know those are tall orders.
I did a year of combined commuting to Seattle from Puyallup. Some days and legs required a bus trip, most involved stowing in the train.
Here's my commuter for those days, as it sat on the train. I had to carry it up 3 flights of stairs when I got to Seattle.

[Grant-53]

That would be the basis of an aero commuter. I worked 6 years for a company that made the interiors for commuter train cars. Our regional buses have front racks for bicycles. An aero shell would not have to be much longer than the overall length of a typical bicycle. A commuter bike does not have to follow UCI rules. There are plans of sailplanes that could be sized and shortened to a Kamm tail.

[skyking]

I beat myself back into bicycle shape that year, then took a hard fall and tore both rotator cuffs bad. I kept riding but eventually had to get surgeries.
The train commute was great. I could ride the train in, and then ride as far as I wanted back home on bike paths that ran with the tracks more or less. I would ride as far as I felt like, then get on the train to get to my car.