Rim fatigue failure

On Thursday, April 23, 2020 at 8:50:49 AM UTC-7, Frank Krygowski wrote:
On Wednesday, April 22, 2020 at 11:12:26 PM UTC-4, Sir Ridesalot wrote:
On Wednesday, 22 April 2020 21:52:37 UTC-4, Frank Krygowski wrote:

I'll add that "you can be the safest driver and get killed" sometimes
gets interpreted as "It doesn't matter what you do." But I believe
drivers who are properly attentive and smart, who watch for situations
developing, get into far fewer crashes.

I'm frequently amazed at motorists rushing ahead into situations I spot
from half a mile back. Not crashes, necessarily, although I've seen some.

BTW, my closest call in the past 20 years happened last October. Driving
a crowded, hilly, up-and-down interstate 26 through South Carolina, I
was in a line of cars in the left lane making our way past a semi on an
uphill. There was a sudden loud bang, and the semi headed for the
shoulder. The semi's driveshaft came sliding and rotating down the lane
line. Not spinning on its long axis - rotating like a thrown tomahawk..

I swerved left as far as I could, which wasn't really far enough. But at
the moment I passed it, it happened to be parallel to the lane line. I
squeezed by on its left. The guy behind me wasn't as lucky.

For a long time after that, the interstate was very peaceful.

--
- Frank Krygowski

Tell that to my father who had slowed for other traffic on an on-ramp to an expressway and an idiot driver plowed into the back of his vehicle at high speed. Sometimes Lady Luck just isn't with you. You're very fortunate to have had so many miles driving and bicycling without any relatively serious mishaps.

I assume your "Tell that..." refers to my sentence " I believe drivers who are
properly attentive and smart, who watch for situations developing, get into far
fewer crashes."

Please note that I did not say "get into NO crashes." Yes, bad things can happen
to good people.

But are you really going to claim that it's all just "Lady Luck"? That being
competent has no effect on one's crash history? Sorry, that's nonsense.

I probably avoided some crashes by being "very fortunate." But I'm sure I avoided
far more crashes by being watchful, careful and competent. Others can do the same.

Others often don't do the same. I don't think people should be cowering in fear, but there are rational reasons for having auto safety standards and safer cars. I once avoided a multi-car highway crash only to get rear-ended by an oncoming PU truck. "Fwew, missed that . . . smash." The impact pushed me and my family into the cars I had missed and collapsed our 4Runner. We walked away. I suspect the outcome would have been much worse in a '63 Corvair -- at least based on my experience with old cars in crashes.

-- Jay Beattie.

On 4/23/2020 2:28 PM, jbeattie wrote:
On Thursday, April 23, 2020 at 8:50:49 AM UTC-7, Frank Krygowski wrote:
On Wednesday, April 22, 2020 at 11:12:26 PM UTC-4, Sir Ridesalot wrote:
On Wednesday, 22 April 2020 21:52:37 UTC-4, Frank Krygowski wrote:

I'll add that "you can be the safest driver and get killed" sometimes
gets interpreted as "It doesn't matter what you do." But I believe
drivers who are properly attentive and smart, who watch for situations
developing, get into far fewer crashes.

I'm frequently amazed at motorists rushing ahead into situations I spot
from half a mile back. Not crashes, necessarily, although I've seen some.

BTW, my closest call in the past 20 years happened last October. Driving
a crowded, hilly, up-and-down interstate 26 through South Carolina, I
was in a line of cars in the left lane making our way past a semi on an
uphill. There was a sudden loud bang, and the semi headed for the
shoulder. The semi's driveshaft came sliding and rotating down the lane
line. Not spinning on its long axis - rotating like a thrown tomahawk.

I swerved left as far as I could, which wasn't really far enough. But at
the moment I passed it, it happened to be parallel to the lane line. I
squeezed by on its left. The guy behind me wasn't as lucky.

For a long time after that, the interstate was very peaceful.

--
- Frank Krygowski

Tell that to my father who had slowed for other traffic on an on-ramp to an expressway and an idiot driver plowed into the back of his vehicle at high speed. Sometimes Lady Luck just isn't with you. You're very fortunate to have had so many miles driving and bicycling without any relatively serious mishaps.

I assume your "Tell that..." refers to my sentence " I believe drivers who are
properly attentive and smart, who watch for situations developing, get into far
fewer crashes."

Please note that I did not say "get into NO crashes." Yes, bad things can happen
to good people.

But are you really going to claim that it's all just "Lady Luck"? That being
competent has no effect on one's crash history? Sorry, that's nonsense.

I probably avoided some crashes by being "very fortunate." But I'm sure I avoided
far more crashes by being watchful, careful and competent. Others can do the same.

Others often don't do the same. I don't think people should be cowering in fear, but there are rational reasons for having auto safety standards and safer cars. I once avoided a multi-car highway crash only to get rear-ended by an oncoming PU truck. "Fwew, missed that . . . smash." The impact pushed me and my family into the cars I had missed and collapsed our 4Runner. We walked away. I suspect the outcome would have been much worse in a '63 Corvair -- at least based on my experience with old cars in crashes.

Everybody's got anecdotes, Jay. I don't have them about car crashes, but
I have some about near misses.

Have motor vehicles gotten safer? Yes, especially for those inside.
(They seem to have gotten more dangerous for pedestrians and possibly
bicyclists.)

But please don't make that an argument against what I was advocating:
Being watchful, careful and competent.


--
- Frank Krygowski

On Monday, April 20, 2020 at 3:55:11 PM UTC-7, pH wrote:
On Monday, April 20, 2020 at 12:54:14 PM UTC-7, Mark J. wrote:
On 4/20/2020 6:18 AM, AMuzi wrote:
This was in my overnight email:

https://www.youtube.com/watch?v=qKeeHDuoFq8

Thanks, Andy, this was the best thing I've found on R.B.T. in years!

To everybody: IF you haven't watched the video yet, it's rather long
and slow, but worth the time, IMHO. There is actual data obtained by
actual /measurements/ made in a /systematic/ way.

It's admittedly very wonky, but this is a TECH group, yes?

Oh, and it happens to confirm a bunch of my preconceived notions, though
I also learned some new things, e.g. WHY spoke-hole cracks nearly always
start running toward the next spoke hole rather than toward the braking
surface.

In my youth, I ran a lot of tandem wheels at low tension, so I have a
lot of experience with rim cracks. The video makes a very persuasive
case that higher tension would have helped, and why.

It also makes a pretty impressive case (at first glance!) for Sapim
spoke nipples and washers, though maybe DTs have the same noted
features. Good to think about any such claims critically.

Mark J.

Boy, if ever a thread cried out for a good old Jobst and Sheldon commentary. Sigh.

I wore out a Specialized front rim one time in my life as the metal began to bulge. (brake wear).

Since I'm a 27" curmudgeon I hope my Mavic Mod 4's hold up for the next decade or two, I have not found spares. (Should have bought the Velocity Dyad while Peter White had them.)
I have a Wolber in the basement just in case.
I run 48H in back and 40H in front since I am a Clydesdale....I think Chalo said he is, too, and Ron Wallenfang might be one besides.

Thanks for the link.
pH in Aptos

https://www.probikekit.com/bicycle-w.../12056928.html