November 12, 2019 Login  


Weird Crash
Last Post 10/31/2019 06:25 PM by Cosmic Kid. 40 Replies.
Printer Friendly
Sort:
PrevPrev NextNext
You are not authorized to post a reply.
Page 1 of 3123 > >>
Author Messages
6ix

Posts:298

--
10/20/2019 12:13 PM
Was on descent yesterday with a very strong crosswind.  Got up to a little over 40mph when i made the decision to basically brake to a near complete stop as it felt unsafe.  had knees clamped on top-tube and was bracing myself.  While decelerating, my bike went out of control.  The wheels seemed to be oscillating and violently shaking the bike even as I braked.  Felt like both wheels had turned oval and I had blown out the tires (I hadn't.  Wheels were perfectly true.)  I ended up crashing in the ditch and breaking my hand in three places. 

I'm not super light at 158 lbs and was on my Chapter 2 Rere with the latest Mavic Cosmics.  I've experienced crazy crosswinds before even to the point of having to put a foot down.  But I've never had my bike suddenly start bobbing up and down so violently that i lose control. 

This took me forever to type since hand is in cast. 
Orange Crush

Posts:2628

--
10/20/2019 02:29 PM
Sorry to hear that 6ix. Heal well.

Where you cold? I've had similar sensations basically caused by intense shaking of my body due to cold.

As it happens I did a 12k descent in torrential rain and frigid temperatures yesterday (it was supposed to be dryish) but I only started feeling really cold at bottom.
6ix

Posts:298

--
10/20/2019 05:54 PM
nah, wasn't cold at all. mid 60's, i think. I have been cold enough to shake before and that isn't what happened. Something bizarre happened with the aerodynamics of the wheels causing it to violently bob up and down even though i was trying to come to a stop. Might shoot this over to Zinn at Velonews.
smokey52

Posts:297

--
10/20/2019 06:29 PM
resonant frequencies? https://en.wikipedia.org/wiki/Tacoma_Narrows_Bridge_(1940)
79pmooney

Posts:2200

--
10/20/2019 07:05 PM
What model Cosmics? I went to their website and see that the Cosmic name covers a huge array of rim depths and shapes. Being an aero geek (specifically from the lift side of the equation, not so much the drag) I want to know exactly what rim shape acted so badly. (I was fascinated by sail theory since I was a kid The two most important books I owned were "Theory of Wing Sections" by Abbott and Von Doenhoff and Sailing Theory and Practice" by C. A. Marchaj. Still have them.

I wonder if your particular rim was alternating between attached flow and creating lift and detached flow, creating far less lift.

Ben
79pmooney

Posts:2200

--
10/20/2019 07:06 PM
Bah!  Double post
79pmooney

Posts:2200

--
10/20/2019 07:07 PM
Bah!  Double post
79pmooney

Posts:2200

--
10/20/2019 07:08 PM
Bah!  Double post
79pmooney

Posts:2200

--
10/20/2019 07:12 PM
Bah!  Double post
79pmooney

Posts:2200

--
10/20/2019 07:14 PM
Bah!  Double post
79pmooney

Posts:2200

--
10/20/2019 07:15 PM
Bah!  Double post
79pmooney

Posts:2200

--
10/20/2019 07:15 PM
Bah!  Double post
79pmooney

Posts:2200

--
10/20/2019 07:16 PM
Bah!  Double post
79pmooney

Posts:2200

--
10/20/2019 07:18 PM
Bah!  Double post
huckleberry

Posts:546

--
10/20/2019 08:41 PM
For god's sake, Ben!

; )
You are not authorized to post a reply.
Page 1 of 3123 > >>


Active Forums 4.1
NOT LICENSED FOR PRODUCTION USE
www.activemodules.com

Latest Forum Posts
My TiCycles goes low Q posted in Gear Advice

No Amgen Tour of California 2020 posted in Professional Racing

Met another warrior yesterday posted in Road Cycling

Weird Crash posted in Road Cycling

politics posted in The Coffee Shop

Zinn's new Clydesdale posted in Gear Advice

Gravel bikes posted in Gear Advice

No articles match criteria.
  Terms and Conditions | Privacy Policy  Copyright 2008-2013 by VeloNation LLC