More on disk brakes and wheel ejection

In article ,
"John Rees" wrote:

Well, I didn't see the rest of the discussion. Your post stands as
the first in the thread on my newsreader. The post you responded
to and quoted was undated, makes it tough for me to located the
original thread..

I was the original poster and let me clarify a few things. First, the
title of this thread is the title I used for my first post, but that
was several weeks ago (and it was promptly ignored by most of the loud
voices trying to shout down james Annan). The odds are it's spooled
off your news server some time ago, but you can find the original post
at Google.

You can also find a lot of other posts on this very topic- search for
James Annan as the author and you'll find them.

In article ,
(Spider) wrote:

Why? AFAIK, there has been *no* experiemental research done on this
system. If there are published articles, could you please post a
link? I am very interested.

I did. The very first article in this thread was by me posted July
17th, prompted by seeing publication of experimental research that
confirms there *is* a problem with current disk brake fork design.
The doubting Thomases promptly ignored it.

You can find it at Google. You can also find the reference article at:

http://www.singletrackworld.com/article.php?sid=1063

Tim McNamara wrote in message ...
In article ,
(Spider) wrote:

Why? AFAIK, there has been *no* experiemental research done on this
system. If there are published articles, could you please post a
link? I am very interested.

I did.

No, you didn't. The German firm gave STW some preliminary results,
but I could not find a single, published article on this - and by that
I mean an article that describes the materials and conditions under
which the preliminary result was discovered. IOW, a scientific
article, published in a peer-reviewed journal.

The very first article in this thread was by me posted July
17th, prompted by seeing publication of experimental research that
confirms there *is* a problem with current disk brake fork design.
The doubting Thomases promptly ignored it.

No, that article *did not* contain published work that describes the
experiment.

I apologize for not being clear on what I meant by "published
article." The world of science attaches something wholly different to
this term than the layman, and it behooves me to make that clear.

Again, my apologies.

Spider

In article
,
Dave Lehnen wrote:

That would require re-desining the calipers, n'es-ce pas?

snip

If the caliper is moved from the rear of the left fork to the front
of the right fork, the hydraulic line or cable would still exit in
about the correct (upwards) direction.

You have to modify both the fork and the caliper mounts, so it requires
redesigning the whole system. It makes non sense to revamp the caliper
when the real problem is the hub-fork interface.

--
Fact of life #15: Heads bleed, walls don't.

Maki wrote:
In article
,
Dave Lehnen wrote:


That would require re-desining the calipers, n'es-ce pas?


snip

If the caliper is moved from the rear of the left fork to the front
of the right fork, the hydraulic line or cable would still exit in
about the correct (upwards) direction.


You have to modify both the fork and the caliper mounts, so it requires
redesigning the whole system. It makes non sense to revamp the caliper
when the real problem is the hub-fork interface.


For most calipers, you only need to modify the fork, as suggested
above. An exception would be calipers like the Shimano XT, with
different diameter leading and trailing pistons.

Dave Lehnen

In article
,
Dave Lehnen wrote:

For most calipers, you only need to modify the fork, as suggested
above. An exception would be calipers like the Shimano XT, with
different diameter leading and trailing pistons.

Oh, sorry. I missed the "from left to right part".
Yes, in theory it will work, but I'm not sure all the calipers are made
to brake backwards. The pads may very well be more supported in one way
than the other. And you still need to replace the fork, usually the most
expensive part.
I don't understand what's wrong with improved skewers.

--
Fact of life #15: Heads bleed, walls don't.

Why bother moving anything? Just replace the open end dropout with a
bolt on retainer, like on motorcycle F forks? Dio we really need thirty
second wheel changes on a MOUNTAIN BIKE, for Christ's sake?

May you have the wind at your back.
And a really low gear for the hills!
Chris

Chris'Z Corner
"The Website for the Common Bicyclist":
http://www.geocities.com/czcorner

In article ,
Rick Onanian wrote:

I saw skewers the other day that have a lock against
unintentional loosening. They have a spring-loaded
button you must press to release or turn/loosen them.

Suppose these would help?

IMHO yes. Experience shows that QRs that exceed by far the current iso
standards exist, so it is clearly possible to make them strong enough.
It remains the problem of sloppy users that dont' tighteen enough, so
the QR can unscrew. With the lock this is gone too.
However the ISO standard should be updated and require a specific logo
on the skewer so that one can distinguish the good ones.

--
Fact of life #15: Heads bleed, walls don't.

In article ,
Maki wrote:

In article ,
Rick Onanian wrote:

I saw skewers the other day that have a lock against
unintentional loosening. They have a spring-loaded button you
must press to release or turn/loosen them.

Suppose these would help?

IMHO yes. Experience shows that QRs that exceed by far the current
iso standards exist, so it is clearly possible to make them strong
enough. It remains the problem of sloppy users that dont' tighteen
enough, so the QR can unscrew.

Not so sure that this last sentence is really accurate.

In article ,
Maki wrote:

Calipers are fine where they are, the weak link is the wheel/hub
interface.

No, the problem is that the fork design is flawed. Not the wheel/hub
interface, not the QRs, etc. The fork puts the caliper in exactly the
right place to push the wheel out of the dropout. Annan has
demonstrated this quite clearly, yet people like yourself insist on
shilly-shallying around looking for some kludge to try to overcome a
significant design flaw.

Why is this so difficult to comprehend? People's lives quite
literally depend on this. The design should be corrected to prevent
the wheel from being ejected from the dropout even if the skewer is
left open, if it unscrews, if it breaks under tension, or whatever.
The wheel should NEVER be forced out of the dropout as a result of
braking!