Amazing ridership with disintegrating wheel
Tim McNamara
carbon fiber disc wheel gets smaller and smaller until it looks like
they are brought down by a pedal strike. Amazing that the captain kept
it upright as long as he did.
http://www.youtube.com/watch?v=Ngv7Iu3y1o0
and another astonishing save, which has been posted before:
http://www.youtube.com/watch?v=Y-z0Kh0pvNM
--
"I wear the cheese, it does not wear me."
Nate Nagel
> Track tandem blows a front tire, and in Flintstone fashion the front
> carbon fiber disc wheel gets smaller and smaller until it looks like
> they are brought down by a pedal strike. Amazing that the captain kept
> it upright as long as he did.
>
> http://www.youtube.com/watch?v=Ngv7Iu3y1o0
nice nerves o' steel. I'd have probably flinched.
nate
--
replace "roosters" with "cox" to reply.
http://members.cox.net/njnagel
Peter Rathmann
> Track tandem blows a front tire, and in Flintstone fashion the front
> carbon fiber disc wheel gets smaller and smaller until it looks like
> they are brought down by a pedal strike. Amazing that the captain kept
> it upright as long as he did.
>
> http://www.youtube.com/watch?v=Ngv7Iu3y1o0
Tubular wheels are frequently credited as being more rideable than
clincher ones in the event of a puncture. Guess that doesn't apply to
light carbon fiber disc models.
DougC
> On Sat, 6 Mar 2010 17:31:12 -0800 (PST), Peter Rathmann
> <prat...@yahoo.com> wrote:
>
>> Tubular wheels are frequently credited as being more rideable than
>> clincher ones in the event of a puncture. Guess that doesn't apply to
>> light carbon fiber disc models.
I wonder if it did the track flooring any favors also....
>
> CF is unsuitable for structural components on a bicycle due to its
> failure mode. Ride it with that knowledge.
PURE cf/composite is unsuitable.
With many (non-bicycle) CF items I've seen they used at least one layer
of kevlar in the middle somewhere. The kevlar is tough and holds things
together if the carbon get shattered.
~
Tim McNamara
<ced56b51-873d-4182...@s36g2000prh.googlegroups.com>,
Peter Rathmann <prat...@yahoo.com> wrote:
I don't know why that myth exists. A flat tubular is more likely to
come off the rim than a flat clincher IME.
Tim McNamara
DougC <dci...@norcom2000.com> wrote:
> On 3/6/2010 8:47 PM, * Still Just Me * wrote:
> > On Sat, 6 Mar 2010 17:31:12 -0800 (PST), Peter Rathmann
> > <prat...@yahoo.com> wrote:
> >
> >> Tubular wheels are frequently credited as being more rideable than
> >> clincher ones in the event of a puncture. Guess that doesn't apply to
> >> light carbon fiber disc models.
>
> I wonder if it did the track flooring any favors also....
There's something I hadn't thought about. I did think about shard of CF
out there waiting for the tires of other competitors.
Chalo
>
> Track tandem blows a front tire, and in Flintstone fashion the front
> carbon fiber disc wheel gets smaller and smaller until it looks like
> they are brought down by a pedal strike. Amazing that the captain kept
> it upright as long as he did.
>
> http://www.youtube.com/watch?v=Ngv7Iu3y1o0
I wonder how their time on that run compares to another run using a
real tire on a real wheel.
Equipment that goes the distance has higher performance, in real
appreciable terms, than equipment that saves a tiny bit of weight or
aero drag but quickly fails. That principle works as well when the
relevant units are seconds as when they are decades.
Chalo
carl...@comcast.net
Dear Chalo,
Some improved spoked wheels may be as good or even better than disks
in zero side wind, but nothing else does as well as a disk with a side
wind, where the sail effect can actually produce a slight negative
drag.
A somewhat dated page with a table showing drag for several wheels:
http://www.analyticcycling.com/WheelsConcept_Disc.html#Wheel%20Aerodynamics
The conventional 36-spoke wheel has a drag coefficient of 0.0491,
about 35% higher than the 0.0361 and 0.0364 for the two disks tested.
If you plug in the 0.0491 and the 0.0361 wheel drags for both wheels
in the pursuit calculator on that site, the two-disk bike leads by
1.192 seconds and 17.2 meters after a standing start 4k run:
The results:
http://tinyurl.com/yghdwwk
The calculator:
http://www.analyticcycling.com/WheelsPursuit_Page.html
If you double the power from 550 watts to 1100 watts as a crude
estimate of a tandem, the 4k lead drops to 0.8 seconds and 15 meters.
Of course, rear disks are pretty much standard in high-level time
trials.
Cheers,
Carl Fogel
carl...@comcast.net
<noEmai...@stillnodomainey.com> wrote:
>On Tue, 9 Mar 2010 11:49:45 -0800 (PST), "carl...@comcast.net"
><carl...@comcast.net> wrote:
>
>>Dear Chalo,
>>
>>Some improved spoked wheels may be as good or even better than disks
>>in zero side wind, but nothing else does as well as a disk with a side
>>wind, where the sail effect can actually produce a slight negative
>>drag.
>
>Isn't that video of an indoor track? The wind would be minimal
>indoors, I'd wager :-)
Dear S,
Yes, but I thought that it was worth pointing out the striking sail
effect.
You did know about that, right? :-)
Cheers,
Carl Fogel
thirty-six
> In article <FBNkn.4409$ao7.1...@newsfe21.iad>,
>
> DougC <dcim...@norcom2000.com> wrote:
> > On 3/6/2010 8:47 PM, * Still Just Me * wrote:
> > > On Sat, 6 Mar 2010 17:31:12 -0800 (PST), Peter Rathmann
>
> > >> Tubular wheels are frequently credited as being more rideable than
> > >> clincher ones in the event of a puncture. Guess that doesn't apply to
> > >> light carbon fiber disc models.
>
> > I wonder if it did the track flooring any favors also....
>
> There's something I hadn't thought about. I did think about shard of CF
> out there waiting for the tires of other competitors.
>
> --
> "I wear the cheese, it does not wear me."
Ban them. That's a damn good reason.
thirty-six
> Peter Rathmann <prathm...@yahoo.com> wrote:
>
> > On Mar 6, 2:50 pm, Tim McNamara <tim...@bitstream.net> wrote:
> > > Track tandem blows a front tire, and in Flintstone fashion the
> > > front carbon fiber disc wheel gets smaller and smaller until it
> > > looks like they are brought down by a pedal strike. Amazing that
> > > the captain kept it upright as long as he did.
>
> > >http://www.youtube.com/watch?v=Ngv7Iu3y1o0
>
> > Tubular wheels are frequently credited as being more rideable than
> > clincher ones in the event of a puncture. Guess that doesn't apply
> > to light carbon fiber disc models.
>
> I don't know why that myth exists. A flat tubular is more likely to
> come off the rim than a flat clincher IME.
>
> --
> "I wear the cheese, it does not wear me."
A stuck tub stays stuck even with deflation. Motor paced and events
with sprinting should have their tyres shellacked in place. Wired on
tyres are never safe on the track because of the loss of control which
is inherrent when using a lightweight cover which becomes quickly
deflated.
thirty-six
wrote:
> On Tue, 9 Mar 2010 11:49:45 -0800 (PST), "carlfo...@comcast.net"
>
> <carlfo...@comcast.net> wrote:
> >Dear Chalo,
>
> >Some improved spoked wheels may be as good or even better than disks
> >in zero side wind, but nothing else does as well as a disk with a side
> >wind, where the sail effect can actually produce a slight negative
> >drag.
>
> indoors, I'd wager :-)
I'd rather be outdoors when the audience is fuelled up on burgers and
beers.