The Chainlink

Chicago Divvy bikes blowing in the wind, 31 Oct 2014

Found this online, OMG

Views: 1857

▶ Reply to This

Replies to This Discussion

Permalink Reply by BruceBikes on November 5, 2014 at 5:00pm

Despite h's and Brent's obvious trolling (bravo gentlemen), I find this video fascinating.

For those interested in a (dubious?) scientific explanation, winds last Friday afternoon were out of the N to NNW, according to the weather station on the Harrison-Dever Crib.  Sustained windspeeds were over 50 mph and gusts were over 65 mph.  This Divvy station, located on inner Lake Shore Drive at Ohio, has virtually no shelter from the full force of the wind coming down the lake.  Assuming a flat surface area of around 2 square feet for the rear triangle and skirt guard, simplistic wind load calculations suggest these winds could put a load of 25 to 45 lbs on the bikes.  As the bikes themselves weigh only 40 lbs, it seems reasonable these winds could pick up the back end of the bike.

Permalink Reply by Duppie on November 5, 2014 at 5:06pm

I found the video more than fascinating. 

Glad to hear that it would take significant more wind to lift up the docking stations itself (a Divvy employee mentioned that each segment weighs about 300lb.)


BruceBikes said:

Despite h's and Brent's obvious trolling (bravo gentlemen), I find this video fascinating.

For those interested in a (dubious?) scientific explanation, winds last Friday afternoon were out of the N to NNW, according to the weather station on the Harrison-Dever Crib.  Sustained windspeeds were over 50 mph and gusts were over 65 mph.  This Divvy station, located on inner Lake Shore Drive at Ohio, has virtually no shelter from the full force of the wind coming down the lake.  Assuming a flat surface area of around 2 square feet for the rear triangle and skirt guard, simplistic wind load calculations suggest these winds could put a load of 25 to 45 lbs on the bikes.  As the bikes themselves weigh only 40 lbs, it seems reasonable these winds could pick up the back end of the bike.

Permalink Reply by Doug Haynes on November 5, 2014 at 5:49pm

Just so ya know.

Brent Powell said:

Sorry "notorious" (what does that even mean lol) nice try.

Permalink Reply by h' Zerocats on November 5, 2014 at 5:56pm
Marketing effort? To show that Divvy bikes blow around in extreme wind and therefore you should ride them?>>

Am I the only one here that remembers Megawhoosh?
https://www.google.com/#q=megawoosh
Permalink Reply by Lisa Curcio on November 5, 2014 at 7:21pm

Never hoid of it, but I pretty much live in a cave.  Are you trolling h'?

h' 1.0 said:

Marketing effort? To show that Divvy bikes blow around in extreme wind and therefore you should ride them?>>

Am I the only one here that remembers Megawhoosh?
https://www.google.com/#q=megawoosh
Permalink Reply by Matt M. 18.5KM on November 5, 2014 at 8:46pm
Awesome.

BruceBikes said:

Despite h's and Brent's obvious trolling (bravo gentlemen), I find this video fascinating.

For those interested in a (dubious?) scientific explanation, winds last Friday afternoon were out of the N to NNW, according to the weather station on the Harrison-Dever Crib.  Sustained windspeeds were over 50 mph and gusts were over 65 mph.  This Divvy station, located on inner Lake Shore Drive at Ohio, has virtually no shelter from the full force of the wind coming down the lake.  Assuming a flat surface area of around 2 square feet for the rear triangle and skirt guard, simplistic wind load calculations suggest these winds could put a load of 25 to 45 lbs on the bikes.  As the bikes themselves weigh only 40 lbs, it seems reasonable these winds could pick up the back end of the bike.

Permalink Reply by Haddon on November 5, 2014 at 9:33pm

- I sent the original video poster a message and he may reply.

- I would go with real.  If you were going to fake this the easiest way would probably be to have people on the other side of the wall pulling fishing line, shoot the video and then go back and scrub the line from the film. There are 6 bikes moving in total and all the manpower (3-4 people) needed to move them and shot video and then one would have to take out any digital artifacts left by the fishing line is a fucking shit ton of frame by frame work. 

For the work it would take to do this you could do something else that was actually cool and impressive. To spend the time and effort to make some bikes swing around is pretty lame. I think the wind vs. surface are analysis provided is far more compelling.

The other video from the same persons youtube account.

Permalink Reply by Mike Schwab on November 5, 2014 at 11:18pm
Permalink Reply by Daniel I. Applebaum on November 6, 2014 at 8:02am

Well, I'm the guy who shot this video on my ride home from work on Friday, 31 Oct.  I'm honestly amazed that anybody thinks this is fake because I can't even figure out how to fake it if I wanted to do do.

On that day, I couldn't take my normal route home due to the winds preventing me from rounding Lake Point Tower.  The front wheel of my 50 lb Dutch omafiets was literally lifted off the of the ground and the whole bike pivoted 180 degrees while I was standing, holding the bike, trying to stay upright.  That happened again near this Divvy station.

Also, why is it so hard to think that a bike can be lifted partially off of the ground by wind?

Anyway, as others have said, there was a north wind, and the station is oriented north-south, so the buildings around and the wall served to direct the wind straight down that stretch of sidewalk.  It was hard to walk against the wind.

Dan.

Permalink Reply by h' Zerocats on November 6, 2014 at 8:18am

Thanks, Mike!

Mike Schwab said:

Permalink Reply by Daniel I. Applebaum on November 6, 2014 at 8:27am


Exactly!

Dan.


Haddon said:

...

For the work it would take to do this you could do something else that was actually cool and impressive.

...

Permalink Reply by Lisa Curcio on November 6, 2014 at 8:36am

Cameron, that is an analogy that I think I can remember.  Thank you!
 
Cameron 7.5 mi said:

I'm at least close enough to a scientist that I could play one on TV. The easiest way to picture how Chicago's buildings impact wind is to think of a river. This isn't an entirely accurate comparison because unlike water, air is a compressible fluid and there are many more variables at play, but the concept is similar. When a calm flowing river hits a series of rocks it forms a rapids as the water searches for a path around the rocks. The water flow becomes turbulent as the water has to change direction to flow around the rocks and the current becomes faster as the rocks restrain the flow of the river and force it through a smaller area. When a strong wind blows into Chicago, buildings in the Loop and River North basically act like rocks in a rapids, producing strong winds in unexpected directions.



Lisa Curcio 4.1mi said:

I am no scientist and don't even play one on TV, but I am pretty sure concrete walls deflect wind, not absorb wind.  Someone on this site once explained the whole windsheer thing that happens with buildings in Chicago.  Maybe that person is still around and could refresh our memories.

Brent Powell said:

Sorry but you're wrong. It's fake. Fake fake fake.

There's that 2 ft tall wall right there that would have absorbed a huge amount of the wind necessary to lift the bike. Even with that rear fender, the cross section of the bike isn't very large relative to it's weight. 

RSS

Groups

© 2008-2016   The Chainlink Community, L.L.C.   Powered by

Disclaimer  |  Report an Issue  |  Terms of Service