Cannondale's tests of disks and QRs
 

At last, I've got hold of a report of Cannondale's disk brake/QR test
(you may recall that the CPSC asked them for help last year). It makes
interesting reading.

They tested a single fork/QR/brake combination. None of the components
are named, although the brake seems to be Magura Louise (the brake
_pads_ are described as such). The bicycle was secured in a test rig
with powered rollers under each wheel, rotating at 15.5mph.

I'm not going to type it all in, but this section is taken directly from
the test description:

"A light hand force of 5 lbs was applied to the brake lever every 10
seconds for 3 seconds duration. This caused braking torque to be applied
to the wheel. The drums had 3 equally-spaced cleats (0.5" high the same
as those used on wheel fatigue test T027) to create bumps for the front
wheel to go over."

And then we have:

"Conclusion:

"The conclusion is that the braking action of disc brakes is not causing
the quick release mechanism to unscrew. This test is unable to cause
loosening. At this time there are no reasons to believe that anything is
missing or over constrained in this test."

James
--
If I have seen further than others, it is
by treading on the toes of giants.
http://www.ne.jp/asahi/julesandjames/home/

James Annan wrote:

"The conclusion is that the braking action of disc brakes is not
causing the quick release mechanism to unscrew. This test is unable
to cause loosening. At this time there are no reasons to believe that
anything is missing or over constrained in this test."

See Yellow Pages under "whitewash suppliers"

Guy
--
May contain traces of irony. Contents liable to settle after posting.
http://www.chapmancentral.co.uk

88% of helmet statistics are made up, 65% of them at Washington
University

James Annan wrote:
snip
"The conclusion is that the braking action of disc brakes is not causing
the quick release mechanism to unscrew. This test is unable to cause
loosening. At this time there are no reasons to believe that anything is
missing or over constrained in this test."


james, did you check out the pics i posted of my own disk brakes?

dropout he
http://home.comcast.net/~carlfogel/d...d/Img_3199.jpg

info shot of setup he
http://home.comcast.net/~carlfogel/d...d/Img_3196.jpg

there's no evidence of slippage. there /is/ evidence of indentation
where the axle serrations bite into the fork.

James Annan typed

"A light hand force of 5 lbs was

Umm... I used to have a grip of 100lb[1]. Of what would 5lb be representative?

[1] measured by hand surgeon doing research.

--
girlie

--
Helen D. Vecht:
Edgware.

In article ,
says...
James Annan typed

"A light hand force of 5 lbs was

Umm... I used to have a grip of 100lb[1]. Of what would 5lb be representative?

[1] measured by hand surgeon doing research.

Reflexive grip caused by sneezing?

Jon

Helen Deborah Vecht wrote:
James Annan typed

"A light hand force of 5 lbs was

Umm... I used to have a grip of 100lb[1]. Of what would 5lb be
representative?

[1] measured by hand surgeon doing research.

--
girlie

What are you doing Friday night?

Bill "Shaun was thinking it too" S.

S o r n i Wrote:
Helen Deborah Vecht wrote:
James Annan typed

"A light hand force of 5 lbs was

Umm... I used to have a grip of 100lb[1]. Of what would 5lb be
representative?

[1] measured by hand surgeon doing research.

--
girlie

What are you doing Friday night?

Bill "Shaun was thinking it too" S.

Bill, YOU kill me!! LOL

S o r n i strikes again.


--
mark_kendrick

In message , James Annan
writes
At last, I've got hold of a report of Cannondale's disk brake/QR test
(you may recall that the CPSC asked them for help last year). It makes
interesting reading.

"Conclusion:

"The conclusion is that the braking action of disc brakes is not causing
the quick release mechanism to unscrew. This test is unable to cause
loosening. At this time there are no reasons to believe that anything
is missing or over constrained in this test."

James

0.5" bumps and 5lb of brake effort!!! What's missing Mr Cannondale is
realism.

--
Steve

jim beam wrote:

James Annan wrote:
snip

"The conclusion is that the braking action of disc brakes is not causing
the quick release mechanism to unscrew. This test is unable to cause
loosening. At this time there are no reasons to believe that anything
is missing or over constrained in this test."


james, did you check out the pics i posted of my own disk brakes?

Yes, but if you thought I'd be interested in a single case of "my wheel
didn't slip" then you have missed the point very very badly indeed.

Now, have you any "reasons to believe that anything is missing or over
constrained in this test"?

Inquiring minds want to know...

James
--
If I have seen further than others, it is
by treading on the toes of giants.
http://www.ne.jp/asahi/julesandjames/home/

On Wed, 15 Sep 2004 20:40:53 +0900, James Annan
wrote:

[snip]

zzzzz, zzzzz, zzzz,
Bill